Common use of Tenant Improvement Allowance Clause in Contracts

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A

Tenant Improvement Allowance. Commencing Subject to the terms of this Section 38 set forth below, there shall be paid by the Landlord as the Landlord’s contribution toward Tenant’s Initial Alterations, the sum (“Allowance”) of January $7,191,555.84, based upon a contribution of $68.04 per rentable square foot for 105,696 rentable square feet in the Initial Premises. Tenant shall submit to Landlord Tenant’s good faith estimate (“Qualified Cost Estimate”) of the Qualified Costs (hereinafter defined) to be incurred by Tenant in connection with its move to and the construction of Initial Alterations in the Premises. Installments of the Allowance shall be payable in accordance with the procedures set forth below. Installments of the Allowance, which shall in no event exceed in the aggregate the amount of the Allowance, shall be paid to Tenant (or, at Landlord’s option if Landlord reasonably determines that Tenant is not paying its contractors and such failure to pay may give rise to a lien against the Building, to the order of the contractor that performed the work set forth in the respective invoices) or, at Tenant’s option to Tenant’s contractors, with respect to Qualified Costs theretofore incurred by Tenant (and not theretofore paid to Tenant or which were Tenant’s responsibility as set forth in this Article 38) for which Tenant has submitted a requisition consisting of, (i) in the case of other than costs incurred under architectural and engineering contracts (collectively “Professional Services Contracts”) or under construction contracts, such as furniture or moving or professional fees that are contracted for by Tenant separate from construction and Professional Services Contracts, paid invoices, (ii) in the case of Professional Services Contracts, invoices, and (iii) in the case of construction costs (a) an application for payment and sworn statement of a contractor performing general contracting work in the Premises substantially in the form of AIA Document G-702 covering all work for which disbursement is to be made to a date specified therein which is part of the construction contract; (b) a certification from an AIA architect substantially in the form of the Architect’s Certificate for Payment which is located on AIA Document G702, Application and Certificate of Payment; (c) contractor’s, project managers and subcontractor’s waivers of liens which shall cover all applicable items of Qualified Costs under such construction contracts for which disbursement is being requested and any other statements and forms required for compliance with the mechanics’ lien laws of the Commonwealth of Massachusetts, together with invoices with respect to such Qualified Costs and such other supporting data as Landlord or Landlord’s Mortgagee may reasonably require; (iv) a cost breakdown for each trade or subcontractor performing the work included in Qualified Costs for which a request for disbursement under such construction contracts is being made; (v) copies of all construction contracts for the such Alterations, together with copies of all change orders, if any; and (iii) a request to disburse from Tenant containing an acknowledgement by Tenant of the work done and a good faith estimate of the cost to complete the Initial Alterations to the Premises. Upon completion of the Initial Alterations, and as part of the requisition for final disbursement of the Allowance for hard construction costs, Tenant shall furnish Landlord with: (1) general contractor and architect’s completion affidavits, 2011(2) full and final waivers of lien, (3) receipted bills covering all labor and materials expended and used, (4) as-built plans of the Alterations, and (5) the certification of Tenant’s architect to the Landlord that, based on on-site observation and the data comprising the application for disbursement, to the best of the architect’s knowledge, information and belief, the Alterations have progressed as indicated in the application, the quality of the Alterations is in accordance with the construction contract documents and the contractor is entitled to; payment of the amount certified in the application. Notwithstanding the foregoing, if the Qualified Cost Estimate exceeds the Allowance, Tenant shall be entitled to use payments with respect to any requisition in accordance with the “Tenant Improvement Allowance”, as defined terms hereof except that each individual disbursement of the Allowance by Landlord shall be in Section 2 of this Amendment, for the costs relating same ratio to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement amount properly requisitioned as the Allowance items,” as that term is defined in Section 2.2.1, below bears to the Adjusted Qualified Cost Estimate (collectively, the “Tenant Improvements”hereinafter defined). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT AAdjusted

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use the “"Tenant Improvement Allowance”", as defined in Section 2 5 of the Summary to this AmendmentLease, for the costs relating to the initial design and construction of Tenant’s improvements 's improvements, which are permanently affixed to the Premises or which are otherwise “"Tenant Improvement Allowance itemsItems,” " as that term is defined in Section 2.2.1, below (collectively, the “"Tenant Improvements”"). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s 's construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s 's approval of the “"Final Working Drawings”", as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly following any earlier termination of this Lease, at Tenant’s 's expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is for which disbursement has not disbursed or allocated for disbursement been requested by December 31, 2013the end of the first eighteen (18) months following the Lease Commencement Date, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing A. Subject to Tenant’s compliance with the provisions of this Exhibit, Landlord shall provide an allowance for the planning, designing, obtaining approvals of, permitting, and construction of the Tenant Improvements to be performed in the Premises, as described in the Initial Plans and the Approved Final Drawings, in the amount of January 1, 2011, Tenant shall be entitled to use Six Hundred Seventy Thousand 00/100 Dollars ($670,000.00) (the “Tenant Improvement Allowance”). Tenant shall not be entitled to any credit, as defined abatement or payment from Landlord in Section 2 the event that the amount of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” specified above exceeds the actual Tenant Improvement Costs. The Tenant Improvement Allowance shall only be used for costs and expenses relating to tenant improvements typically installed by Landlord in buildings similar to that of which the Premises are located which are generic in nature and that will likely be used by a subsequent tenant for normal use of the Premises (referred to herein as that term is defined in Section 2.2.1, below (collectively, the “Tenant Generic Improvements”). In no event shall Landlord be obligated For example, Generic Improvements would include items such as new or relocated office demising walls and Building Standard electrical, plumbing and mechanical fixtures, equipment and distribution and telecommunications and network installations useable by any subsequent tenant, while items such as lab equipment and cabling and piping specific to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any business operations would not be considered Generic Improvements. The Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds shall be the sum of maximum contribution by Landlord for the Tenant Improvement AllowanceCosts. All Tenant Improvements for which the Tenant Improvement Allowance has been made available Landlord shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice have no obligation to pay to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term all or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance unless Tenant timely complies with all time requirements hereunder and such that all work is not disbursed or allocated for disbursement by December 31completed and the Tenant [UNREADABLE] Allowance shall include all reasonable costs and expenses associated with the design, 2013preparation, shall revert approval, planning, construction and installation of the Tenant Improvements (the “Tenant Improvement Costs”), including a construction management fee payable to Landlord in the amount of three percent (3%) of the Tenant Improvement Allowance (the “CM Fee”). The Tenant Improvement Allowance shall be the maximum contribution by Landlord for the Tenant Improvement Costs, and the disbursement of the Tenant shall have no further rights with respect thereto. EXHIBIT AImprovement Allowance is subject to the terms contained hereinbelow.

Tenant Improvement Allowance. Commencing as of January 1Provided Tenant is not in default under this Lease beyond any applicable cure period, 2011, Landlord hereby grants to Tenant shall be entitled to use the “Tenant Improvement Allowance, for use to reimburse Tenant for actual out-of-pocket costs incurred and paid for by Tenant during the period commencing on the Lease Commencement Date and expiring on November 30, 2015 (the “TI Allowance Period”, as defined ) in Section 2 connection with the improvement and/or refurbishment of the Premises pursuant to and in accordance with the terms of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below Article 8 (collectively, the “Tenant Improvements”); provided that Tenant may only apply up to an aggregate amount of the Tenant Improvement Allowance equal to $3.00 per rentable square foot of the Premises toward the cost of professional fees (such as engineers, architects, space planners and interior designers), subject to and conditioned upon Landlord’s receipt of all information (including mechanics lien releases, if applicable) reasonably requested by Landlord. In no event shall Landlord be obligated to make disbursements pursuant to this Any costs incurred by Tenant Work Letter or otherwise in excess of the Tenant Improvement Allowance in connection with Tenant’s construction the performance of the Tenant Improvements or any shall be the sole responsibility of Tenant. Following Tenant’s substantial completion of the Tenant Improvement Improvements, Landlord shall reimburse Tenant for the reasonable, actual, third-party, out-of-pocket costs (which costs may include, without limitation, labor and materials costs, professional fees (such as engineers, architects, space planners and interior designers and permitting fees)) incurred by Tenant during the TI Allowance Items, as defined below, Period in a total performing the Tenant Improvements (up to the amount which exceeds the sum of the Tenant Improvement Allowance. All , but after first subtracting a construction oversight fee equal to five percent (5%) of the total cost of the Tenant Improvements) within thirty (30) days following Landlord’s receipt from Tenant of evidence reasonably satisfactory to Landlord that Tenant has paid for and completed the Tenant Improvements for which in full and in accordance with the terms hereof and that there will be no liens recorded against the Building arising out of or relating to the Tenant Improvement Allowance has been made available Improvements, which evidence shall be deemed Landlordinclude: (a) properly executed, unconditional final mechanic’s property under lien releases from Tenant’s architect/space planner, engineers, consultants, contractors, vendors, subcontractors, laborers, and material suppliers retained and/or used by Tenant (“Tenant’s Agents”), showing the terms amounts paid, in compliance with California Civil Code Sections 8132, 8134, 8136 and 8138; (b) Tenant’s contractor’s last application and certificate for payment (AIA form G702 1992 or equivalent) signed by Tenant’s architect/space planner; (c) a breakdown sheet (AJA form 0703 1992 or equivalent); (d) original stamped building permit plans; (e) copy of the Leasebuilding permit; provided, however, Landlord may, by written notice to Tenant given concurrently (f) original stamped building permit inspection card with Landlord’s approval all final sign-offs; (g) full size bond copies and a CD R disk containing electronic files of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end built” drawings of the Lease Term or promptly following any earlier termination of this LeaseTenant Improvements in both “dwg” and “pdf’ formats, at from Tenant’s expensearchitect/space planner for architectural drawings, to remove any and from Tenant’s contractor for all other trades; (h) air balance reports; (i) excess energy use calculations; (i) one year warranty letters from Tenant’s Agents; (k) manufacturer’s warranties and operating instructions; (l) final punchlist completed and signed off by Tenant and Tenant’s architect/space planner; (m) letters of compliance from Tenant’s engineers stating that the engineers have inspected the Tenant Improvements and to repair that they comply with the engineers’ drawings and specifications; (n) a copy of the recorded Notice of Completion; and (o) a final list of all contractors/vendors/consultants retained by Tenant in connection with the Tenant Improvements and any damage to other improvements in the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Section 8.6, which final list shall set forth the full legal name, address, contact name (with telephone/fax/e mail addresses) and the total price paid by Tenant Work Letter (includingfor goods and services to each of such contractors/vendors/consultants; provided that Landlord has determined that no substandard work exists which adversely affects the mechanical, without limitationelectrical, Larc improvements) which constitute standardplumbing, nonheating, ventilating and air conditioning, life-extraordinary improvements for ordinary officesafety or other systems of the Building, laboratory and/or Larc uses the curtain wall of the Building, the structure or exterior appearance of the Building, or any other tenant’s use of such other tenant’s leased premises in biotech facilitiesthe Building. Any Landlord shall have no obligation to disburse any portion of the Tenant Improvement Allowance with respect to any Tenant Improvements that is not disbursed or allocated for disbursement by December 31are performed after the expiration of the TI Allowance Period, 2013, and any such unused amounts of the Tenant Improvement Allowance as of the end of the TI Allowance Period shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as As of January 1the Effective Date, 2011and for a period of twelve (12) months following the first day of the first month thereafter, Tenant shall be entitled to use a tenant changes allowance (the “Tenant Improvement Changes Allowance”, as defined in Section 2 ) of this Amendment, up to TEN DOLLARS ($10.00) per useable square foot of the Premises for the costs relating to the design and construction a total maximum Tenant Changes Allowance of Five Hundred Seventy Five Thousand Four Hundred Dollars ($575,400.00) for Tenant’s improvements or which are otherwise “use in making Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”Changes, as that term is defined in Section 3.312 of the Lease, below, require Tenant, prior to the end Premises. Alternatively, Landlord will allow Tenant to apply up to Eight Dollars ($8.00) per useable square foot of the Premises ($460,320.00) to offset (“Rent Offset”) Monthly Basic Rent during the twelve month period commencing on the first day of the first month following the Effective Date. No later than sixty (60) days after the Effective Date, Tenant shall give Landlord written notice of its election to use either the Tenant Changes Allowance to effect Tenant Changes to the Premises or the Rent Offset to offset Monthly Basic Rent or a combination of both on a per square foot basis. For example, Tenant may elect to use $250,000 of Tenant Changes Allowance and $325,400 of Rent Offset. In the event and to the extent that Tenant elects to utilize the Tenant Changes Allowance, the provisions of Section 12 of the Lease Term or promptly following any earlier termination shall apply to all such Tenant Changes completed within the aforementioned twelve (12) month period and the provisions of this LeaseExhibit “C”, at Tenant’s expenseWork Letter Agreement, to remove any Tenant Improvements and to repair any damage shall apply to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion disbursement of the Tenant Improvement Changes Allowance just if such Tenant Change Allowance were in fact the Tenant Improvements Allowance under Exhibit “C”. In the event and to the extent that is not disbursed Tenant fails to utilize the Tenant Changes Allowance or allocated for disbursement by December 31notify Landlord of its intent to apply the Rent Offset as provided in this Second Amendment, 2013then and in such event, shall revert the Tenant will be deemed to Landlord have elected the Rent Offset and Tenant shall have no further rights with respect thereto. EXHIBIT Awill be entitled to the Rent Offset described in this paragraph.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Landlord and Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which hereby acknowledge the Tenant Improvement Allowance has been which Landlord made available to Tenant pursuant to Section VI of the Fifth Amendment (the “Fifth Floor TI Allowance”). Notwithstanding the early termination of the Lease Term as it relates to the Existing Fifth Floor space, as such early termination is more fully described in Section VI of this Sixth Amendment above, in the event that any of the Fifth Floor TI Allowance remains un-advanced by Landlord to Tenant upon the Existing Fifth Floor Space Lease Expiration Date as such is defined above (such un-used TI being referred to herein as the “Un-Used Fifth Floor TI”), Landlord hereby agrees to make such Un-Used Fifth Floor TI available to Tenant for Tenant’s use in defraying the total cost of any approved Tenant Alterations made by Tenant to Suite 500. The terms regarding the availability of any Un-Used Fifth Floor TI shall continue to specify, per the agreed terms of Section VI of the Fifth Amendment, that an $18,500.00 portion thereof shall only be made available by Landlord to Tenant if Tenant, in writing, conclusively waives its right, via formal written notice to Landlord, to terminate the Lease Term as it relates to the Suite 500 early, as outlined in Section IV above. Any improvements Tenant shall make to Suite 500 and any advancements by Landlord to Tenant of the Un-Used Fifth Floor TI funds shall be deemed Landlord’s property under pursuant to the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior Workletter attached to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing Landlord shall provide a Tenant Improvement Allowance of $250,000 to be used to fund costs associated with Tenant’s build out of the Premises, including without limitation plumbing, electrical, and HVAC, but excluding any soft costs other than architectural fees and general contractor fees. Up to $75,000 of the $250,000 can be spent on personal property items for use in the Premises, such as a modular clear room, and that may be removed from the Premises on termination of January 1the Lease, 2011subject to compliance with Section 6.12. Prior to commencement of construction of Tenant Improvements, Tenant shall be entitled provide Landlord with plans and specifications for all such Improvements, together with a construction contract (with a general contractor reasonably acceptable to use Landlord), a construction line item monthly budget and any necessary permits from the Town of Natick (the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant ImprovementsConstruction Documents”). In no event No work on Improvements shall commence until Landlord has approved all the Construction Documents, such approval not to be obligated to make disbursements pursuant to this Tenant Work Letter unreasonably withheld, conditioned or otherwise in connection with Tenant’s delayed. After commencement of construction of the Tenant Improvements or Improvements, Tenant shall submit to Landlord monthly a requisition for reimbursement of costs incurred for work put in place (less any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum retainage of not more than 5% of the requisition) during the preceding month with detailed information as to vendor, amount and work performed. Tenant Improvement Allowanceshall also provide lien waivers from all contractors, sub-contractors and vendors. All Tenant Improvements for which the Tenant Improvement Allowance Landlord may require an inspection report by its designated agent to certify that work has been made available shall be deemed Landlord’s property under performed in compliance with the terms of the Lease; provided, however, Construction Documents. Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, may also require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, a title update (at Tenant’s expense, ) to remove confirm the absence of any Tenant Improvements and liens relating to repair any damage to the Premises and Building caused work performed by such removal and return the affected portion or on behalf of the Premises to a Building standard general office condition; provided, however, that Tenant. Landlord shall not pay each monthly requisition (less any retainage) within ten (10) business days of receipt and acceptance of all the foregoing in form and substance reasonably satisfactory to Landlord. If any item exceeds the budgeted amount for that item for that month, then Landlord may require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of pay the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert excess amount prior to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Amaking any payment on the requisition.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as Provided that Tenant is not in default under the Lease beyond any applicable notice and cure period, Landlord shall provide a tenant improvement allowance of January 1, 2011, Tenant shall be entitled to use $35.00 per rentable square feet in the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, Expansion Premises ($635,215.00) for the hard and soft costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise incurred in connection with Tenant’s construction of 's Work in the Expansion Premises, plus $5.00 per rentable square feet in the Current Premises($ 183,925.00) for the hard and soft costs incurred in connection with Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, 's Work in a total amount which exceeds the sum of Current Premises (the Tenant Improvement "TI Allowance"). All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that The term "Tenant's Work" is defined in Section 3.3Exhibit B (Work Letter). The TI Allowance is applicable to sales tax, belowdesign costs, require permitting costs, and a construction supervision fee payable to Landlord's agent (in the amount of $150/hour, not to exceed 15 hours/week) but is not applicable to cabling, telecommunications, fixturing, equipment or moving costs. Upon completion of Tenant's Work and issuance of the permanent certificate of occupancy for the Expansion Premises (the "CofO"), prior Tenant shall provide to Landlord documentation satisfactory to Landlord of the costs of Tenant's Work along with copies of lien releases from Tenant's contractor and all subcontractors or material men providing work or materials and detailed breakdowns of the cost incurred by Tenant 5 /s/ CL for Landlord's cost segregation and depreciation purposes. Landlord shall reimburse Tenant for the cost of Tenant's Work up to the end TI Allowance and Additional Allowance within 30 days after receipt of the Lease Term or promptly following any earlier termination foregoing and issuance of this Leasethe CofO. The TI Allowance and Additional Allowance shall each be available for draw until March 1, at Tenant’s expense, to remove any Tenant Improvements 2021 only and to repair any damage to the Premises and Building caused by such removal and return the affected no disbursements will be available thereafter. Any unused portion of the Premises to a Building standard general office condition; provided, however, that TI Allowance and/or Additional Allowance shall be retained by the Landlord and shall not require be either refunded to Tenant to remove upon termination or expiration available as a credit against any obligations of this Tenant under the Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”), as defined of eighty-five dollars ($85) per square foot contained in Section 2 of this Amendment, the Leased Premises for the costs relating to the initial design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below Improvements (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of Improvements shall not include any Shell Work. If the Tenant Improvements or plus any additional costs of any change orders total more than the Tenant Improvement Allowance, then that amount shall be considered the “Over-Allowance ItemsAmount.” Such Over-Allowance Amount shall be paid by reimbursement to Landlord in whole or part within fifteen (15) days of the date Tenant receives an itemized and certified statement from Landlord documenting (i) the calculation and back-up information concerning the Over-Allowance Amount; and (ii) Landlord’s expenditure of the entire Tenant Improvement Allowance. It is the intent of the parties that Tenant shall be responsible for the whole of the Over-Allowance Amount, as defined belowunless otherwise agreed in writing by Landlord and Tenant, in a total but that Tenant will have no obligation to pay the Over-Allowance Amount until Landlord has exhausted the full amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which If the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of costs are less than the Tenant Improvement Allowance, then the Base Rent shall be decreased to reflect the savings using the same methodology that would be used for any Over-Allowance Amount (that is not disbursed or allocated is, the savings would be amortized over the same term as the permanent financing obtained by Landlord for disbursement by December 31, 2013, shall revert the Project to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Adetermine the per square foot dollar reduction).

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a ---------------------------- one-time tenant improvement allowance (the “"Tenant Improvement Allowance”") in an amount up to, but not exceeding, the product of (i) $20.00 and (ii) the number of rentable square feet of the Suite 600 Space as defined in Section 2 of this Amendmentthe Lease Commencement Date, to be used to help Tenant pay for the costs relating to the of design and construction of Tenant’s 's improvements or set forth in the approved Final Drawings (as defined herein) which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “"Tenant Improvements”") and the other Tenant Improvement Allowance Items (as such term is defined below). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that which is not used to pay for the Tenant Improvement Allowance Items; provided, however, to the extent there remains any unused portion of the Tenant Improvement Allowance and thus Landlord is not providing any Additional Allowance, Tenant may use such excess to help Tenant pay for any Alterations Tenant installs in the Premises pursuant to Article 8 of the Lease after substantial completion of the Tenant Improvements. Such excess amount shall be disbursed or allocated for disbursement by December 31, 2013, shall revert Landlord after Tenant has completed the Alterations and has delivered to Landlord appropriate invoices, paid receipts, lien releases and Tenant shall have no further rights with respect thereto. EXHIBIT Aother information reasonably requested by Landlord.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the Lease or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011the cost of construction of the Tenant Improvements shall be paid or reimbursed by Landlord up to a maximum amount equal to $2,364,672.00 (the “Tenant Improvement Allowance”), which amount is being made available by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Premises. Tenant shall be responsible, at its sole cost and expense, for payment of the entire Cost of Improvements of the Tenant Improvements in excess of the Tenant Improvement Allowance, including (but not limited to) any costs or cost increases incurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “entire Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, toward the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction Cost of Improvements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or any Tenant Improvement Allowance Items, as defined below, charges set forth in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to in this Tenant Work Letter (including, without limitation, Larc improvementsLetter) which constitute standard, non-extraordinary improvements prior to being required to expend any of Tenant’s own funds for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe Tenant Improvements. Any portion The funding of the Tenant Improvement Allowance that is not disbursed shall be made on a monthly basis or allocated for disbursement at other convenient intervals mutually approved by December 31, 2013, shall revert to Landlord and Tenant and in all other respects shall have be based on such commercially reasonable disbursement conditions and procedures as Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no further rights circumstances shall the Tenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for any Cost of Improvement (or any other cost or expense) associated with any moveable furniture or trade fixtures, personal property or any other item or element which, under the applicable provisions of the Lease, will not become Landlord’s property and remain with the Building upon expiration or termination of the Lease. Notwithstanding anything to the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for and the Tenant Improvement Allowance shall not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials, if any, but with respect thereto. to removal and remediation of any such Hazardous Materials, only to the extent such removal or remediation is required by Applicable Laws enforced as of the date of this Lease for improvements in the Premises generally (as opposed to the specific Tenant Improvements) and to the extent the same required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary occupancy density; (b) costs to bring the Project into compliance with Applicable Laws to the extent required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary office occupancy density; (c) construction costs in excess of the contract amount stated in the contract with the General Contractor, as approved by Tenant (not to be unreasonably withheld), except for increases set forth in change orders approved by Tenant; (d) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed); (e) attorneys’ fees incurred in connection with negotiation of Bayside Acquisition, LLC EXHIBIT AB [Britannia Life Science Center] construction contracts, and attorneys’ fees, experts’ fees and other costs in connection with disputes with third parties; (f) interest and other costs of financing construction costs; (g) costs incurred as a consequence construction defects or default by a contractor; (h) costs as a consequence of casualties; (i) penalties and late charges attributable to Landlord’s failure to pay construction costs, and (j) costs due to compliance with any soil management plan for the Project or its appendices

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “"Tenant Improvement Allowance”"), as defined in the amount set forth in Section 2 5 of this Amendmentthe Summary, for the costs relating to the initial design and construction of Tenant’s 's improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “"Tenant Improvements”"). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of Tenant Improvement Allowance and "Landlord's Drawing Contribution," as that term is defined in Section 3.1, below. In the event that the Tenant Improvement AllowanceAllowance is not fully disbursed by Landlord to, or on behalf of, Tenant on or before the date which is one (1) year following the Lease Commencement Date, then such unused amounts shall revert to Landlord, and Tenant shall have no further rights with respect thereto. Any Tenant Improvements that require the use of Building risers, raceways, shafts and/or conduits, shall be subject to Landlord's reasonable rules, regulations, and restrictions, including the requirement that any cabling vendor must be selected from a list provided by Landlord, and that the amount and location of any such cabling must be approved by Landlord. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly given following any earlier termination of this Lease, require Tenant, at Tenant’s 's expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require their condition existing prior to the installment of such Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT AImprovements.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, which amount shall include Space Planning Allowance and Construction Management Fee for the costs relating to the design design, permitting and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds to be constructed at the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office conditionPremises; provided, however, that Landlord shall not require Tenant have no obligation to remove upon termination disburse all or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated to Tenant unless Tenant makes a request for disbursement by pursuant to the terms and conditions set forth below. Landlord shall have no obligation to disburse all or any portion of the Tenant Improvement Allowance if Tenant makes a request for a disbursement of the Tenant Improvement Allowance on or after December 31, 20132016. Without limiting the foregoing, the portion of the Tenant Improvement Allowance to be expended by Landlord for space planning, shall revert not exceed the Space Planning Allowance. Subject to Landlord the provisions of the Lease, the Tenant Improvement Allowance shall be used to pay for any actual, out-of-pocket costs and expenses incurred in connection with the design and engineering work performed by Tenant under Section 2.5.1(a) above and for the permitting and construction of the Tenant Improvements pursuant to the Plans and Specifications performed by Tenant pursuant to Section 2.5.1(b) above, provided that such costs and expenses are deemed Qualified Expenses. For the avoidance of doubt, no portion of the Tenant Improvement Allowance shall be used to pay for the costs and expenses of any work at the Premises not included in the Plans and Specifications, and Tenant shall have no further rights be responsible, at its sole cost and expense, for all costs and expenses incurred in connection with respect theretosuch work. EXHIBIT ALandlord shall reimburse Tenant for any actual, out-of-pocket costs and expenses which constitute Qualified Expenses paid by Tenant for the Tenant Improvements up to the amount of the Tenant Improvement Allowance. Landlord’s payment of such amount shall not be deemed Landlord’s approval or acceptance of the work furnished or materials supplied in connection with the Tenant Improvements as set forth in Tenant’s payment request. Tenant shall pay the applicable excess out of its own funds if, when and to the extent that (a) the cost of the Tenant Improvements exceeds the Tenant Improvement Allowance, or (b) the cost of space planning exceeds the Space Planning Allowance. Tenant shall not be entitled to a credit for any unused portion of the Tenant Improvement Allowance. Landlord shall be entitled to receive the Construction Management Fee from the Tenant Improvement Allowance and the Supplement Tenant Improvement Allowance, if applicable, in connection with its management of the construction of the Tenant Improvements.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the Lease or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011the cost of construction of the Tenant Improvements shall be paid or reimbursed by Landlord up to a maximum amount equal to $145 per RSF of the Premises (i.e. $5,525,805.00 (the “Tenant Improvement Allowance”), which amount is being made available by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Premises. Tenant shall be responsible, at its sole cost and expense, for payment of the entire Cost of Improvements of the Tenant Improvements in excess of the Tenant Improvement Allowance, including (but not limited to) any costs or cost increases incurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “entire Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, toward the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction Cost of Improvements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or any Tenant Improvement Allowance Items, as defined below, charges set forth in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to in this Tenant Work Letter (including, without limitation, Larc improvementsLetter) which constitute standard, non-extraordinary improvements prior to being required to expend any of Tenant’s own funds for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe Tenant Improvements. Any portion The funding of the Tenant Improvement Allowance that is not disbursed shall be made on a monthly basis or allocated for disbursement at other convenient intervals mutually approved by December 31, 2013, shall revert to Landlord and Tenant and in all other respects shall have be based on such commercially reasonable disbursement conditions and procedures as Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no further rights circumstances shall the Tenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for any Cost of Improvement (or any other cost or expense) associated with any EXHIBIT B moveable furniture or trade fixtures, personal property or any other item or element which, under the applicable provisions of the Lease, will not become Landlord’s property and remain with the Building upon expiration or termination of the Lease. Notwithstanding anything to the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for and the Tenant Improvement Allowance shall not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials in the Premises, if any, but with respect thereto. EXHIBIT Ato removal and remediation of any such Hazardous Materials, only to the extent such removal or remediation is required by Applicable Laws enforced as of the date of this Lease for improvements in the Premises generally (as opposed to the specific Tenant Improvements) and to the extent the same required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary office occupancy density; (b) costs to bring the Project into compliance with Applicable Laws to the extent required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary office occupancy density; (c) construction costs in excess of the final contract amount in the contract with the General Contractor, as approved by Xxxxxx (not to be unreasonably withheld), except for increases set forth in approved change orders; and (d) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed);.

Tenant Improvement Allowance. Commencing as Landlord agrees that it will provide to Tenant an allowance of January 1, 2011, Tenant shall be entitled to use $4,300,000 (the “Tenant Improvement Allowance” or “TIA”, as defined in Section 2 of this Amendment, ) which shall be used to pay for the costs relating to the design and construction of TenantLandlord’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined belowWork, in a total amount which exceeds accordance with the sum of Final Plans and Specs. Tenant shall have the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice right to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion apply part of the Tenant Improvement Allowance that toward the costs of Tenant design, preparation, renovation and construction within the Premises including without limitation to Tenant’s Work and may also apply part of the TIA towards non-building related items such as, but not limited to, permitting, space plans, moving, architectural and engineering, attorneys’ fees and expenses, project management, wiring and cabling, special electrical power distribution, telephone and security systems and the purchase and installation of any furniture, fixtures and equipment to be used for or within the Premises. Prior to commencing the Tenant Improvements, Tenant must approve Landlord’s budget for the Landlord’s Work (the “Budget”) and any changes thereto must be approved by Tenant. After the Rent Commencement Date any unused portion of the TIA shall be credited against future Tenant Improvements required for the occupancy by Tenant of additional portions of the Premises as required by the Lease and may also be used by Tenant to cover up to three (3) months Base Rent which shall be amortized over the remaining initial Term of the Lease. When the TIA is not disbursed or allocated entirely expended for disbursement by December 31the purposes set forth in this Lease, 2013including Landlord’s Work, shall revert Tenant hereby agrees to pay to Landlord all costs and expenses in a timely manner in excess of the TIA for unfunded Tenant shall have no Improvements and Landlord’s Work. Tenant further rights agrees to pay all costs for Tenant Improvements for future portions of the Premises to be occupied by Tenant in accordance with respect thereto. EXHIBIT AExhibit B once the TIA is fully expended.

Tenant Improvement Allowance. Commencing Landlord will not charge Tenant for a construction management fee with respect to the Improvements. Landlord will provide Tenant an allowance of up to One Hundred Twenty Three Thousand Six Hundred Ninety and 00/100 Dollars ($123,690.00) (the “First Floor Tenant Improvement Allowance”) (which is equal to Thirty Dollars ($30.00) per square foot of the 4,123 square foot area now known as the library and file room) towards the cost of January the Improvements pursuant to the First Floor Plans. Additionally, Landlord will provide Tenant an allowance sufficient to accomplish the build-out, painting and carpeting of the second floor portion of the Demised Premises pursuant to the Second Floor Plans as identified in Paragraph (1, 2011, ) above with building-standard materials and finishes (the “Second Floor Tenant shall be entitled Improvement Allowance”) toward the cost of the Improvements pursuant to use the Second Floor Plans. The First Floor Tenant Improvement Allowance and the Second Floor Tenant Improvement Allowance are hereinafter collectively referred to as the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no the event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction that the cost and expense of constructing the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of is less than the Tenant Improvement Allowance. All , then Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice entitled to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior a credit equal to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that against the next-due monthly Base Rent, and, if applicable, against any payments of monthly Base Rent due thereafter until such unused portion is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and exhausted. Tenant shall have no further rights be responsible for all costs and expenses of the Improvements (except as otherwise stated in Paragraph 6 below) that exceed the Tenant Improvement Allowance. Tenant shall be responsible for paying any excess with respect theretoto the first floor portion of the Demised Premises directly to Tenant’s Contractor. EXHIBIT AAny excess with respect to the second floor portion of the Demised Premises shall be deemed to be additional rent and shall be payable within fifteen (15) days of receipt of an invoice therefor from Landlord.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”, as defined ) in the amount set forth in Section 2 13 of this Amendment, the Summary for the costs relating to the initial design and construction of Tenant’s improvements or improvements, which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1permanently affixed (including furniture, below fixtures and equipment attached to the walls, ceiling or slab) to the Premises (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of Tenant Improvement Allowance. In the event that the Tenant Improvement AllowanceAllowance is not fully utilized by Tenant on or before the first (1st) anniversary of the Lease Commencement Date, then such unused amounts shall revert to Landlord, and Tenant shall have no further rights with respect thereto. Any Tenant Improvements that require the use of Building risers, raceways, shafts and/or conduits, shall be subject to Landlord’s reasonable rules, regulations, and restrictions, including the requirement that any cabling infrastructure designer must be selected from a list provided by Landlord, and that the amount and location of any such cabling must be approved by Landlord. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly given following any earlier termination of this Lease, require Tenant, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office conditiontheir condition existing prior to the installment of such Tenant Improvements; providedPROVIDED FURTHER; HOWEVER, howeverTHAT (i) NOTWITHSTANDING THE FOREGOING, that Landlord UPON REQUEST BY TENANT AT THE TIME OF TENANT’S REQUEST FOR LANDLORD’S APPROVAL OF THE “FINAL WORKING DRAWINGS, AS THAT TERM IS DEFINED IN SECTION 3.3, BELOW, LANDLORD SHALL NOTIFY TENANT WHETHER ALL OR ANY PORTION OF THE TENANT IMPROVEMENTS WILL BE REQUIRED TO BE REMOVED PURSUANT TO THE TERMS OF THIS SECTION 2.1, (ii) in no event shall not require Tenant be required to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed which (a) are normal and customary business office improvements, (b) do not affect the Base Building, and (c) cannot be seen from the exterior of the Premises, and (iii) in no event shall Tenant be required to remove the catering kitchen permitted pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion the terms of Section 5.1 of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT ALease.

Tenant Improvement Allowance. Commencing Provided that Tenant has delivered the Letter of Credit to Landlord and Tenant is not then in default under this Work Agreement or the Lease beyond the expiration of any applicable notice and grace periods, from and after the Tender Date, except as of January 1otherwise set forth in Paragraph C.3, 2011below, Landlord agrees to provide to Tenant shall be entitled to use the “Tenant Improvement Allowance”, to be applied solely to the Construction Costs. Provided that Tenant has fully performed all of its obligations under the Lease and this Work Agreement, Construction Costs shall be disbursed by Landlord from the Available Allowance, as defined in Section 2 and when such costs are actually incurred by Tenant. Tenant shall submit to Landlord, from time to time, but not more often then once per calendar month, requests for direct payments to third parties, of this Amendmentor for reimbursement to Tenant for Construction Costs incurred by Tenant out of the Available Allowance, which requests shall be accompanied by (a) paid receipts or invoices substantiating the costs for which payment is requested; (b) a signed statement from Tenant certifying that the costs were actually incurred for the stated amount; (c) partial lien waivers from the party supplying the services or materials for which payment is sought; and (d) such other information as Landlord reasonably requires. Provided Tenant delivers to Landlord an approved draw request, prepared as set forth above, Landlord shall pay the costs relating covered by such payment request within thirty (30) days following receipt thereof (but Landlord shall not be obligated to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined make more than one (1) such payment in Section 2.2.1, below (collectively, the “Tenant Improvements”any calendar month). In Notwithstanding the foregoing, in no event shall Landlord be obligated to make disbursements pursuant pay, in the aggregate, an amount in excess of ninety percent (90%) of the Tenant Improvement Allowance until satisfaction of the following conditions: (A) Tenant’s occupancy of the Premises for general business use; (B) Tenant’s execution and delivery to this Tenant Work Letter Landlord of the Lease Memorandum attached to the Lease as Exhibit D; (C) receipt by Landlord of appropriate paid receipts or otherwise invoices and a final lien waiver from the Contractor and each subcontractor and supplier covering all work performed by the subcontractors and all materials used in connection with Tenant’s the construction of the Tenant Improvements; and (D) Tenant’s delivery to Landlord of (1) all receipts, invoices or other documentation reasonably necessary to substantiate ail costs payable by Landlord hereunder; (2) an electronic copy (CD-ROM) of CAD background files of the Tenant’s Plans; (3) an electronic version of the “As-Built” drawings of the Tenant Improvements or any prepared by the Tenant’s Architect; and (4) hard copy scaled drawings of the “As-Built” drawings of the Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds Improvements prepared by the sum Tenant’s Architect. If Tenant does not expend all of the Tenant Improvement Allowance. All Tenant Improvements Allowance for which Construction Costs as permitted hereunder on or before the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms last day of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of thirty-ninth (39lh) full calendar month following the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this LeaseCommencement Date, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance not so used shall be retained by Landlord. Notwithstanding the foregoing, upon thirty (30) days prior written notice to Landlord, up to Six Hundred Thirty-One Thousand Nine Hundred Twenty and 00/100 Dollars ($631,920.00) of the Tenant Improvement Allowance may be used by Tenant (1) as a credit towards the next monthly installment(s) of Base Rent becoming due and payable by Tenant under the Lease, or (2) towards the reimbursement of FF&E Costs (hereinafter defined), provided that is not disbursed or allocated for disbursement by December 31, 2013, shall revert Tenant delivers written notice to Landlord and of its election to apply such portion of the Tenant Improvement Allowance as a rent credit or towards FF&E Costs on or before the last day of the thirty-ninth (39lh) full calendar months following the Commencement Date. In the event Tenant fails to deliver such written notice to Landlord on or before the last day of the thirty-nine (39th) full calendar months following the Commencement Date, Tenant shall have no further waive any and all of its rights with respect theretoto receive such rent credit or reimbursement of FF&E Costs. EXHIBIT AAs used herein, the term “FF&E Costs” shall mean the acquisition and/or installation within the Premises of Tenant’s telecommunications equipment (including wiring and cabling), and furniture, fixtures, equipment, project management services, interior and/or exterior building signage, and stationery to be used or installed in the Premises.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the amount of up to, as defined in Section 2 of this Amendment, for the costs relating but not to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below exceed Eighty Thousand Dollars (collectively, the “Tenant Improvements”$80,000.00). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, Paragraph 5 in a total amount which exceeds the sum of Tenant Improvement Allowance and in no event shall the Tenant Improvement AllowanceAllowance be utilized for any trade fixtures, furniture or equipment (including freezers or coolers) of Tenant. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property under upon the terms expiration or earlier termination of the term of this Lease and may not be removed by Tenant from the Premises at any time unless required by Landlord in accordance with the provisions of Paragraph 11 of the Lease; provided, however, Landlord may, by written notice to . Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination any payment or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, credit for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance. The Tenant Improvement Allowance shall be funded by Landlord upon completion of the installation of improvements (the “Work”) in the Premises and after Tenant has submitted all invoices, lien waivers, affidavits of payment, and such other evidence as Landlord may reasonably require to evidence that the cost of the Work has been paid for and that no mechanic’s, materialman’s or other such liens have been or may be filed against the property or the Premises arising out of the design or performance of the Work. In no event shall Landlord be required to pay any portion of the cost of the Work in excess of the Tenant Improvement Allowance. If the Work is not disbursed or allocated for disbursement by December 31, 2013, shall revert substantially completed with all invoices submitted to Landlord and within twelve (12) months after possession of the Expansion Space is tendered to Tenant, then Landlord shall not be obligated to reimburse Tenant shall have no further rights with respect thereto. EXHIBIT Afor invoices submitted after such date.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the amount of up to, as defined but not exceeding [***] per rentable square foot of the Premises (i.e., an amount up to [***] based on 149,273 rentable square feet in Section 2 of this Amendmentthe Premises), for the costs relating to the initial design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, receive any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements cash payment for ordinary office, laboratory and/or Larc uses in biotech facilities. Any any portion of the Tenant Improvement Allowance that which is not used to pay for the Tenant Improvement Allowance Items (as such term is defined below) or disbursed or allocated following the Effective Date of the Lease in accordance with the terms of this Tenant Work Letter. Notwithstanding the foregoing, an amount not to exceed [***] of any unused amount of the Tenant Improvement Allowance shall be made available to Tenant to help Tenant pay for the actual and documented costs incurred by Tenant (collectively, the “Moving/Cabling/FF&E Costs”) for (i) moving and relocating to the Premises, (ii) installing in the Premises telephone and data cabling for Tenant’s telephone and data equipment in the Premises and for establishing security services for the Premises; (iii) the purchase of and installation of furniture, fixtures and equipment for the Premises; and (iv) the cost of signage for the Premises and the Building. Landlord shall disburse from the Tenant Improvement Allowance the available portion thereof to help Tenant pay for the Moving/Cabling/FF&E Costs actually incurred by Tenant within thirty (30) days after Xxxxxxxx has received Xxxxxx’s written request for disbursement together with copies of invoices from third parties evidencing the amount of such Moving/Cabling Costs to be paid by December 31Landlord. Any remaining balance of the Tenant Improvement Allowance after the Lease Commencement Date may, 2013for the first twelve (12) months after the Lease Commencement Date (but not thereafter), shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Abe used as a credit toward the Base Rent first coming due under the Lease.

Tenant Improvement Allowance. Commencing Landlord will contribute to the costs of designing the Tenant Improvements and performing the Tenant Improvement Work, as depicted on the Approved TI Construction Drawings and any approved Plan Modifications, to the extent of January 1, 2011, the lesser of (a) Thirteen Million Nine Hundred Fifty Three Thousand Six Hundred Sixty and 00/100 Dollars ($13,953,660.00) (calculated at the rate of $70.00 per square foot of rentable area in the Premises) or (b) the actual cost of Permitted Allowance Items (as hereinafter defined) for the Tenant shall be entitled to use Improvement Work (the “Tenant Improvement Allowance”, as defined ). Tenant shall pay all costs in Section 2 excess of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, for the “design of the Tenant Improvements”)Improvements and performance of the Tenant Improvement Work. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise Agreement in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total an amount which exceeds the sum of the Tenant Improvement Allowance. All costs associated with the construction of the Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, shared with Landlord may, by written notice to on an “open-book” basis promptly upon request. Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises shall not be entitled to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, credit for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that is not disbursed in the form of a rent credit, rent abatement or allocated for disbursement by December 31otherwise. Notwithstanding Tenant’s election to initially occupy only one (1) floor of the Premises, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aconstruct Tenant Improvements to the entirety of the Premises and the Tenant Improvement Allowance shall be equitably allocated to Tenant Improvements on each of the floors of the Premises.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use receive from Landlord a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the amount of up to, as defined but not exceeding Two Million One Hundred Seventy-Five Thousand Four Hundred Fifteen and 80/100 Dollars ($) (i.e., One Hundred Ninety-Six and 71/100 Dollars ($196.71) per rentable square foot of the Premises based on 11,059 rentable square feet in Section 2 of this Amendmentthe Premises) , to help pay for the costs relating to of the design design, permitting and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that which is not disbursed or allocated used to pay for the Tenant Improvement Allowance Items (as defined below), except that Tenant may use up to the lesser of (i) Ten Dollars ($10.00) per rentable square foot of the Premises (i.e., up to $110,590.00 based on 11,059 rentable square feet in the Premises) and (ii) an amount equal to fifteen percent (15%) of the total aggregate fair market value of the real and personal property included within the Premises (as determined by Landlord in its sole discretion), to help Tenant pay for the actual and documented costs incurred by Tenant (collectively, the “FF&E Costs”) for the purchase and installation of furniture, fixtures, equipment and cabling for use in the Premises and as a rent credit (not to exceed the Ten Dollars ($10.00) per rentable square foot of the Premises when aggregated with the FF&E Costs). Landlord shall disburse from the Tenant Improvement Allowance the portion thereof to help Tenant pay for the FF&E Costs actually incurred by Tenant within thirty (30) days after Landlord has received Tenant’s written request for disbursement together with copies of invoices from third parties evidencing the amount of such FF&E Costs to be paid by December 31Tenant, 2013but Landlord shall have no obligation to disburse any portion of the Tenant Improvement Allowance to pay for the FF&E Costs: (A) until after the Commencement Date has occurred and (B) with respect to any disbursement request made by Tenant more than one hundred eighty (180) days after the Commencement Date. Except with respect to the foregoing FF&E Costs, Tenant shall be solely responsible for the cost and installation of all data telecom wiring, and furniture, fixtures and equipment as may be required by Tenant and in no event shall the Tenant Improvement Allowance be applied to the cost of any such items. Notwithstanding any provision to the contrary contained herein, to the extent any portion of the Tenant Improvement Allowance is unused by Tenant as of the date which is one hundred eighty (180) days after the Lease Commencement Date, then the remaining balance thereof shall revert to Landlord Landlord, and Tenant shall have no further rights with respect thereto. EXHIBIT Aright to use such amount for any remaining improvements or alterations, nor as a Rent credit or cash allowance.

Tenant Improvement Allowance. Commencing 10.5.1. If and for as of January 1, 2011long as Tenant is not in default under the Lease beyond any applicable grace period, Tenant shall be entitled to use a tenant improvement allowance in the amount of $[*] allocated as follows: $[*] ($[*]/sf) for the Building 8 Expansion Space, and $[*] ($[*]/sf) for the Building 3 Expansion Space (the “Tenant Improvement Allowance” or “Allowance”, as defined in Section 2 of this Amendment, for ). Tenant shall have the costs relating right to apply the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term towards Tenant Improvements within its Premises whereby the Tenant Improvement Allowance is defined not required to be disbursed or allocated towards only the Expansion Spaces. The Tenant Improvement Allowance shall be paid to Tenant in Section 2.2.1, below (collectively, reimbursement for the total out of pocket costs paid by Tenant for the design professional fees and the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s hard costs” of construction of the Tenant Improvements or any Tenant Improvement Allowance Itemsto the Premises, as defined belowincluding architectural and engineering fees, specialty consultants including acoustical and lighting specialists, permitting and expeditor fees, construction of interior improvements including millwork, built-in a furniture, furniture systems, data cabling and wiring, telecommunications systems, relocation expenses, security, studio equipment, project management fees, and other similar expenses in fitting out the Expansion Space. If the total amount which exceeds paid by Tenant for the sum of Tenant Improvements is less than the Tenant Improvement Allowance. All , Tenant Improvements may receive a credit for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected unused portion of the Premises Allowance up to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration $[*] ($[*]/sf) applied towards the next payment(s) of this Lease, or condition its approval upon Base Rental and Tenant’s agreement to remove upon termination or expiration Percentage Share of this LeaseOperating Expenses due, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that until such sum is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aexhausted.

Tenant Improvement Allowance. Commencing Landlord shall reimburse Tenant for the Costs of Tenant Improvements (as hereinafter defined) in an amount not to exceed $174,150 (the “Improvement Allowance”). Landlord shall also provide Tenant up to an additional $164,475 (the “Reimbursable Allowance”) to be applied to the Costs of January 1, 2011, Tenant Improvements. The Improvement Allowance and Reimbursable Allowance shall be collectively referred to herein as the “Allowance”. Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, solely responsible for the costs relating amount by which the Costs of Tenant Improvements exceeds the Allowance. Tenant acknowledges that any request for payment of the Allowance must be delivered to Landlord in the form of AIA Document G702 (Application for Payment) together with evidence of paid invoices and fully executed, notarized lien waivers (without contingency) covering the work for which reimbursement is then being requested; provided that no disbursement of the Allowance shall occur until such time that Landlord has received (a) final, Landlord-approved Construction Drawings signed by Tenant’s architect, (b) a copy of the building permit and (c) a copy of the fully-executed construction contract for the Tenant Improvements. Subject to the design foregoing, Landlord shall make disbursements of the Allowance not more often than once every thirty (30) calendar days within ten (10) business days after the Landlord’s receipt of a requisition therefor, together with all required documentation and construction of after Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction completion of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowancecovered by such requisition. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at After Tenant’s expense, to remove any completion of Tenant Improvements and delivery to repair any damage Landlord of (a) evidence that the Tenant Improvements have been fully paid for, (b) fully executed and notarized final lien waivers for all Tenant Improvements work, (c) as-built plans for all Tenant Improvements signed by Tenant’s architect and (d) an HVAC balancing report reasonably acceptable to Landlord, Landlord shall, after written request from Tenant, disburse to Tenant the final installment of the Allowance to the Premises and Building caused by such removal and return extent Tenant has satisfied the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements requirements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Adisbursement.

Tenant Improvement Allowance. Commencing Landlord will provide a Tenant Improvement Allowance of Five Hundred Thousand 00/100ths Dollars ($500,000.00) toward improvements in 892 and 000 Xxxx Xxxxx. Tenant may allocate this Tenant Improvement Allowance at Tenant’s discretion between the two Premises and the two Leases. However, the total amount to be provided by Landlord for both Leases and both Premises shall be $500,000.00 and no more. The Allowance will be provided as a reimbursement of January money actually expended by Tenant toward new Tenant Improvements (which must be approved by Landlord under the provisions of the Lease relating to construction) prior to December 31, 2005. Subject to the provisions below, reimbursement by Landlord will be made within sixty (60) days of presentation of reasonably adequate documentation evidencing the expenses incurred and confirming that (1) all Tenant Improvements for which reimbursement is sought have been completed; (2) all contractors, 2011materialmen, suppliers, and others entitled to a lien have provided evidence satisfactory to Landlord releasing or waiving any such liens (or a proper Notice of Completion has been filed and the statutory period for filing of liens following recordation of a Notice of Completion has expired in the reasonable opinion of counsel for Landlord); and (3) said funds have actually been expended by December 31, 2005 for the Tenant Improvements approved by Landlord. Upon application for funds in conformity with the above period, Landlord may audit Tenant’s records upon request made within thirty (30) days after the request is made in regard to each such request for reimbursement. Notwithstanding the above provisions, Landlord shall not be obligated to pay any reimbursement to Tenant in accordance with the above prior to March 31, 2005. Tenant may apply for reimbursement of such matters at any time to and including March 31, 2006. Landlord will have no duty to reimburse based on any application which is received by Landlord after such date. Tenant may not apply for reimbursement under this Paragraph 4 more often than three (3) times in any calendar year. In the event of any non-payment of reimbursement which was due to Tenant, after said reimbursement was due under the above provision, the Tenant shall be entitled to use set the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has it should have been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert reimbursed off against Rent due to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aunder either Lease.

Tenant Improvement Allowance. Commencing as The Landlord shall provide to the Tenant an allowance equal to Fifteen Dollars ($15.00) per square foot of January 1, 2011, Tenant shall be entitled to use the Rentable Area of the Leased Premises (the “Tenant Leasehold Improvement Allowance”, as defined in Section 2 of this Amendment, ) for constructing the Tenant’s Work. The Tenant will be permitted to allocate the Leasehold Improvement Allowance to costs relating to but not limited to: construction, moving costs, project management, legal fees, phone and data cabling. At the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1one time election, below (collectively, the “Tenant Improvements”). In no event shall Landlord such election to be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, exercised by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, Landlord prior to the end Commencement Date, the Landlord will increase the amount of the Lease Leasehold Improvement Allowance up to an additional Thirty-Five Dollars ($35.00) per square foot of the Rentable Area of the Premises (the “Additional Allowance”) which additional amount, if any, would be paid as part of and in the same manner as the Leasehold Improvement Allowance and amortized over the last ten (10) years of the initial eleven (11) year Term or promptly following any earlier termination of this Lease, such amortization to commence on the first anniversary of the Commencement Date, at Tenant’s expensea rate of eight percent (8%), which additional amount shall be re-paid by the Tenant to the Landlord as additional Base Rental in addition to the amounts set out in the Section 2.3 of this Lease (Base Rental) and Section 2.3 of this Lease shall be amended accordingly. Notwithstanding the foregoing, the Tenant shall be entitled, at any time during the Term, to remove any Tenant Improvements and to repair any damage pay to the Premises Landlord all of (and Building caused by such removal and return not part of) the affected then current unamortized portion of the Premises Additional Allowance (an “Allowance Repayment”). Upon receipt by the Landlord of the Allowance Repayment, the Base Rental payable by the Tenant during the balance of the Term shall be amended accordingly to reflect such Allowance Repayment. At the option of either party the parties hereto shall enter into a Building standard general office condition; provided, however, that Landlord shall not require Tenant lease amending agreement from time to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement time to remove upon termination or expiration of this Lease, reflect any Tenant Improvements constructed changes in the Base Rental pursuant to this Tenant Work Letter (includingparagraph in a form acceptable to the parties hereto, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilitiesall parties acting reasonably. Any portion The Leasehold Improvement Allowance and any Additional Allowance shall be payable only after the occurrence or completion of all of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Afollowing:

Tenant Improvement Allowance. Commencing as It is agreed and understood that pursuant to the Original Lease Landlord previously provided Tenant a Tenant Improvement Allowance in connection with the construction of January 1Tenant Improvements within the Building, 2011including within the Leased Premises, Tenant shall be entitled to use in the amount of One Million Five Hundred and Fifteen Thousand Seven Hundred and Forty and 72/00 Dollars (the “Tenant Improvement Allowance”), receipt and sufficiency of which is hereby acknowledged by Tenant, used by Tenant for space planning, preparation of the Tenant Improvement Plans (as defined in Section 2 of this Amendmentdescribed below), for the costs relating architectural and engineering services related to the design Tenant Improvement Plans, permitting required in connection with the Tenant Improvement Plans, leasehold improvements (including modifications to the existing building specifications required as a result of the Tenant Improvement Plans), Tenant’s building signage, and other costs incurred by Landlord in connection with the Tenant Improvement Plans or construction of the Tenant’s Improvements. Accordingly, Landlord shall not provide any additional allowance for improvements or alterations to the Leased Premises in connection with this Lease. In the event of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that full and faithful compliance with each and every term is defined in Section 2.2.1, below (collectively, and condition of this Lease the “Tenant Improvements”). In no event Landlord shall Landlord not be obligated entitled to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum return of the Tenant Improvement Allowance. All , however in the event of Tenant’s abandonment of the Leased Premises or Tenant’s Default hereunder resulting in Tenant Improvements being evicted from the Leased Premises (as evidenced by court order or Landlord’s Notice of Default and Termination as provided for which herein) within five (5) years of the Lease Commencement Date Landlord shall, among other remedies provided for in this Lease, be entitled to the full and immediate repayment of the Tenant Improvement Allowance has been made available which Tenant shall be deemed Landlord’s property under repay to Landlord upon demand therefore. However, it is agreed and understood that the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion amount of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement Tenant shall be required to repay to Landlord, as required by December 31, 2013this provision, shall revert to Landlord be reduced by one hundred and Tenant shall have no further rights with respect thereto. EXHIBIT Afifty thousand dollars ($150,000.00) on each anniversary of the Lease Commencement Date hereunder.

Tenant Improvement Allowance. Commencing as of January 1, 2011the date of this Lease, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 5 of the Summary to this AmendmentLease, for the costs relating to the design and construction of Tenant’s improvements improvements, which are permanently affixed to the Premises, are demountable walls or which are otherwise “Tenant Improvement Allowance itemsItems,” as that term is defined in Section 2.2.12.3.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance, subject to Section 2.2 below. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, . Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this LeaseTerm, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that . Landlord shall not require Tenant to remove upon termination or expiration any of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any the Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe extent shown on the Space Plan attached hereto as Schedule 1. Any portion of the Tenant Improvement Allowance and “Additional Improvement Allowance”, as that term is defined in Section 2.2, below, that is not disbursed or allocated for disbursement by December 31, 2013the date that is two (2) years after the full execution and delivery of this Lease, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT ALandlord acknowledges that Tenant plans to perform multiple Tenant Improvement projects during such two (2) year period and that the terms of this Tenant Work Letter shall apply to each such project.

Tenant Improvement Allowance. Commencing Effective as of January 1the expiration of the Wachovia SNDA Termination Period (provided Tenant has not delivered the Wachovia SNDA Termination Notice to Landlord) and the expiration of the Mortgagee Approval Period, 2011if and so long as there is no Event of Default under the Lease and subject to the provisions of this Section 4, Tenant Landlord acknowledges and agrees that Landlord shall be entitled to use contribute the sum of $265,764.00 (the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating ) to the design hard and construction of soft costs, including, without limitation, architectural, design, consulting, permit and engineering fees, related to the Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below to the Premises (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated Tenant may apply up to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum thirty five percent (35%) of the Tenant Improvement Allowance. All Tenant Improvements Allowance to pay for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expenseaudio visual equipment for board rooms, demo/training rooms, computer rooms and other furniture, fixtures and equipment. In addition, Tenant shall have the right to remove use up to 25% of any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31as a rent credit to be applied against future Rent payments (the “Credit Amount”), 2013, shall revert to but Landlord and Tenant shall have no further rights obligation with respect theretoto any remaining unused portion of the Tenant Improvement Allowance if any portion of the Tenant Improvement Allowance above the Credit Amount remains unspent by Tenant as of October 31, 2011. EXHIBIT AFrom time-to-time, but not more than once a month, Tenant may give Landlord a Requisition (as defined below) for so much of the Work Cost (as defined below) as arose since the end of the period to which the most recent prior Requisition related, or, with respect to the first Requisition, for the Work Cost previously incurred. Provided that no Event of Default has occurred and is continuing, within thirty (30) days after Landlord receives a complete Requisition, Landlord shall pay Tenant ninety percent (90%) of the Work Cost reflected in such Requisition and shall withhold the remaining ten percent (10%) of Work Cost (the “Retainage”); and provided that no Event of Default has occurred and is continuing under the Lease, within thirty (30) days after Tenant furnishes Landlord with (x) a final, stamped set of “as built” plans for the Premises from Tenant’s architect which demonstrates that the Tenant Improvements have been completed substantially in accordance with plans and specifications approved by Landlord and (y) its final Requisition which demonstrates that the Tenant Improvements have been substantially completed and paid for in full by Tenant, Landlord shall pay Tenant the Retainage. In the event Landlord fails to pay any portion of the Tenant Improvements for which a Requisition is properly submitted hereunder within thirty (30) days, and such failure continues for more than five (5) days after a notice of intent to deduct from Tenant, then Tenant shall be entitled to offset the Requisition amount against twenty (20%) of the monthly Basic Rent and Additional Rent due under the Lease until such Requisition amount due to Tenant under this Section 4 has been reimbursed in full.

Tenant Improvement Allowance. Commencing Landlord and Tenant hereby acknowledge and agree that the Tenant Improvement Costs (defined in Section 9 below) for the Tenant Improvements, based upon the Initial Plans approved by Landlord and Tenant in accordance with the provisions of Section 4 above, are estimated to be approximately One Million Eleven Thousand Two Hundred Ninety and 00/100 ($1,011,290) (the “Estimated TI Costs”), as more particularly summarized in the Bid Summary attached hereto as Schedule 3. If the actual Tenant Improvement Costs varies from this estimate by more than twenty-five percent (25%), then Landlord may require any of January 1the following, 2011in its sole discretion: (a) except as otherwise provided in Section 3(k) above, changes be made to the Final Drawings to reduce the cost of the Tenant Improvements and Landlord may refuse to sign any construction contract or Change Orders to the construction contract, as the case may be, until such changes are made to the sole satisfaction of Landlord; (b) Tenant to deposit into a separate escrow account cash in an amount equal to the Excess Tenant Improvement Costs (defined in Section 10 below) or Tenant to pay Landlord the amounts set forth in Section 3(k) above, or any combination thereof as directed by Landlord; (c) Tenant to provide to Landlord evidence satisfactory to Landlord, in its sole discretion, that Tenant has adequate financial resources to pay for the Excess Tenant Improvement Costs, as solely determined by Landlord; and/or (d) Tenant to pay all of the Excess Tenant Improvement Costs before Landlord’s contribution of the Tenant Improvement Allowance (defined in Section 10 below) or Tenant to pay Landlord the amounts set forth in Section 3(k) above, or any combination thereof as directed by Landlord. Subject to the foregoing, Landlord shall provide an allowance for the planning and construction of the Tenant Improvements for the Work to be entitled to use performed in the Premises, as described in the Initial Plans and the Final Drawings, in the amount of Seven Hundred Twenty-One Thousand Seven Hundred Ten and 00/100 Dollars ($721,710.00) (the “Tenant Improvement Allowance”) based upon an allowance of Twenty-Two and 00/100 Dollars ($22.00) per rentable square foot for 32,805 square feet of the Premises which is to be improved, as defined described in Section 2 of this Amendment, for the costs relating to Initial Plans and the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the LeaseFinal Drawings; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected a portion of the Tenant Improvement Allowance up to Eight and 00/100 ($8.00) per rentable square foot of the Premises (or a total of up to a Building standard general office condition; Two Hundred Sixty-Two Thousand Four Hundred Forty and 00/100 Dollars ($262,440.00) may be used by Tenant toward the costs of purchasing, transporting and installing the Cubicles and Equipment, provided, however, that Landlord shall purchase not require less than seventy-three (73) Cubicles as provided in Section 35 of the Lease. Tenant shall not be entitled to remove upon termination any credit, abatement or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses payment from Landlord in biotech facilities. Any portion the event that the amount of the Tenant Improvement Allowance that is not disbursed specified above exceeds the actual Tenant Improvement Costs. The Tenant Improvement Allowance shall only be used for generic office non-specific to Tenant’s Permitted Uses, and generic lab improvements, and the Cubicles and Equipment (for purposes of this Section 8, the term “generic lab improvements” means Building Standard finishes (for walls, floors, ceilings, doors, windows, etc.), Building Standard lighting, Building Standard convenience electrical, standard HVAC capacity and distribution for open office area and excludes all plumbing, piping or allocated other mechanical work). The Tenant Improvement Allowance shall be the maximum contribution by Landlord for disbursement by December 31, 2013, the Tenant Improvement Costs and shall revert be subject to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Athe provisions of Section 10 below.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the Lease or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011the cost of construction of the Tenant Improvements shall be paid or reimbursed EXHIBIT B -4- [Britannia Gateway Business Park] [Aligos Thereapeutics, Inc.] by Landlord up to a maximum amount as set forth in Section 5 of the Summary to the Lease (the “Tenant Improvement Allowance”), which amount is being made available by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Premises. Tenant shall be responsible, at its sole cost and expense, for payment of the entire cost of construction (including all design and permit and other associated costs) (collectively, the “Cost of Improvements”) of the Tenant Improvements in excess of the Tenant Improvement Allowance, including (but not limited to) any costs or cost increases incurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “entire Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, toward the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction Cost of Improvements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or any Tenant Improvement Allowance Items, as defined below, charges set forth in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to in this Tenant Work Letter (including, without limitation, Larc improvementsLetter) which constitute standard, non-extraordinary improvements prior to being required to expend any of Tenant’s own funds for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe Tenant Improvements. Any portion The funding of the Tenant Improvement Allowance that is shall be made on a monthly basis or at other convenient intervals mutually approved by Landlord and Tenant and in all other respects shall be based on such commercially reasonable disbursement conditions and procedures as Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no circumstances shall the Tenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for any Cost of Improvement (or any other cost or expense) associated with any moveable furniture or trade fixtures, personal property or any other item or element which, under the applicable provisions of the Lease, will not disbursed become Landlord’s property and remain with the Building upon expiration or allocated termination of the Lease. Notwithstanding anything to the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for disbursement and the Tenant Improvement Allowance shall not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials in the Premises, if any; (b) costs to bring the Project into compliance with Applicable Laws to the extent required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary office occupancy density; (c) construction costs in excess of the contract amount stated in the contract with the General Contractor, as approved by Tenant (not to be unreasonably withheld), except for increases set forth in change orders approved by Tenant; (d) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed); (e) attorneys’ fees incurred in connection with negotiation of construction contracts, and attorneys’ fees, experts’ fees and other costs in connection with disputes with third parties; (f) interest and other costs of financing construction costs; (g) costs incurred as a consequence construction defects or default by a contractor; (h) costs as a consequence of casualties; and (i) penalties and late charges attributable to Landlord’s failure to pay construction costs. Tenant shall use at least twenty percent (20%) of the Tenant Improvement Allowance prior to December 31, 20132019, and the remainder prior to December 31, 2021. Any amounts not so expended shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Landlord shall provide Tenant shall be entitled with a tenant improvement allowance in an amount not exceeding $798,900 in the aggregate (the "Allowance") to use the “reimburse Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating incurred by Tenant in performing initial leasehold improvements to the design Premises and construction for the other items described below in this Section 3.4, including but not limited to architectural and engineering consulting costs, moving costs, telecommunications equipment and installations and the purchase of office furniture, but subject, however, to the limitations described in the next paragraph. The Allowance shall be paid to Tenant (in increments of not less $50,000), upon the submission to Landlord of a written requisition with copies of invoices supporting the costs sought to be reimbursed and, if applicable, (a) lien waivers from Tenant’s 's contractors and (b) a certificate from Tenant's architect certifying to the completion of the percentage of work sought to be reimbursed. Landlord shall pay each such approved requisition within twenty (20) days of its receipt. Notwithstanding the foregoing, Landlord shall only be obligated to pay such requisition submitted by Tenant up to the aggregate amount of the Allowance and only to the extent that the amount described in such requisition shall be included in the budget for Tenant's work that has been approved in writing by Landlord prior to May 15, 2000. At least 50% of the Allowance shall be expended for permanent leasehold improvements or which are otherwise “Tenant Improvement to the Premises, telecommunications wirin g, equipment and installations, and architectural and engineering costs, and no more than 50% of the Allowance items,” as that term is defined in Section 2.2.1, below (collectivelyshall be expended for moving costs, the “Tenant Improvements”)purchase of office furniture and other consultants' costs. In no event event, however, shall Landlord be obligated (i) to make disbursements pursuant any payments to this Tenant Work Letter or otherwise in connection with Tenant’s construction on account of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end Term Commencement Date or (ii) to make any payments to Tenant on account of the Lease Term or promptly following Allowance for requisitions received from Tenant after January 1, 2001, except if Tenant's failure to submit a requisition prior to January 1, 2001 shall be due to Landlord's inability to deliver any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; providedby November 1, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A2000.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant Landlord shall be entitled responsible for creating a "passthrough" in the hallway between Suite 504 and Suite 500 once Suite 500 becomes available. On or before their respective commencement dates, Landlord shall deliver to use Tenant Suite 504 and Suite 500 in their current "As Is" condition, and, except as provided herein, Landlord shall have no obligation whatsoever to provide any alterations or improvements with regard to the “Additional Premises. Landlord shall provide Tenant with an allowance (the "Tenant Improvement Allowance”") of $4,680.00 for Xxxxx 000, as defined in Section 2 of this Amendmentand $14,210.00 for Xxxxx 000, for Tenant's required work in those suites which may be used by Tenant for any improvement it makes to those suites (provided the costs relating to same is made in accordance with the design and construction of Tenant’s improvements or which are otherwise “Lease). The aggregate Tenant Improvement Allowance items,” amount may be allocated by Tenant to improvement work in Suites 500 and 504 as Tenant may elect (e.g., Tenant may elect to shift some of the allowance allocated to Suite 500 over to Suite 504), provided that term is defined in Section 2.2.1Landlord shall not be required to make available the amounts described above until following the commencement of the Lease for each respective Suite (i.e., below (collectively, Landlord shall not be required to make available the “Tenant Improvements”$14,210.00 amount allocated to Suite 500 until after the lease commences with respect to Suite 500). In no event Tenant shall Landlord be obligated to make disbursements construct the tenant improvements for the Additional Premises in accordance with all applicable laws and codes and pursuant to this Tenant Work Letter or otherwise plans and using such contractors as shall be approved in connection with Tenant’s construction of advance by Landlord. Landlord shall pay out the Tenant Improvements or any Tenant Improvement Allowance Itemsas any such work is completed based upon the stage of completion and provided Landlord has received bills and lien releases from Tenant's contractor(s) and/or suppliers, as defined belowsubject to a ten percent (10%) retention to be withheld until final, lien-free completion of the work. Tenant shall pay all costs for constructing its improvements in a total amount which exceeds the sum excess of the Tenant Improvement Allowance. All Tenant Improvements , and shall pay for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements all applicable fees and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Apermits.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement TI Allowance”, as defined ) in Section 2 of this Amendmentthe amount Seven Hundred Twenty Thousand Dollars ($720,000.00), for the costs relating to the initial design and construction of Tenant’s improvements or improvements, including the Landlord Work, which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”), of which Twenty-one Thousand Eight Hundred Dollars ($21,800.00) has already been expended by Landlord for certain work performed on the second floor of the Building (including design costs) at Tenant’s request prior to the commencement of the term of this Lease. Hence, the remaining balance of the TI Allowance is Six Hundred Ninety-eight Thousand Two Hundred Dollars ($698,200.00) (the “Remainder of the TI Allowance”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, Construction Rider in a total amount which exceeds the sum Remainder of the TI Allowance and any portion of the TI Allowance remaining after construction of the Tenant Improvement AllowanceImprovements shall belong to Landlord. Further, Landlord shall have no liability to Tenant for any portion of the TI Allowance not utilized by Tenant for Tenant Improvements to the Premises or FF&E, as provided hereinbelow, on or before December 31, 2019. All Tenant Improvements Improvements, whether paid for which by Landlord or Tenant, shall become a part of the Tenant Improvement Allowance has been made available Premises, shall be deemed Landlord’s the property under of Landlord and, subject to the terms provisions of the Lease; provided, howevershall be surrendered by Tenant with the Premises, Landlord maywithout any compensation to Tenant, by written notice to Tenant given concurrently with Landlord’s approval at the expiration or termination of the “Final Working Drawings”Lease, as that term is defined in Section 3.3, below, require Tenant, prior to accordance with the end provisions of the Lease Term or promptly following any earlier termination Lease. Notwithstanding the foregoing, Tenant shall be permitted to use up to Seventy-five Thousand Dollars ($75,000.00) of this Lease, at the Remainder of the TI Allowance for Tenant’s expensefixtures, to remove any Tenant Improvements furniture and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; providedequipment (“FF&E”), however, that Landlord which FF&E shall not require become the property of Landlord or surrendered by Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of with the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT APremises.

Tenant Improvement Allowance. Commencing as Landlord has agreed to provide Tenant with an allowance of January 1, 2011, Tenant shall be entitled $76,525 for the purpose of making improvements to use the Second Floor Premises (the “Tenant Improvement Allowance”), as defined in Section 2 of this Amendment, subject to the provisions set forth herein. Landlord shall reimburse Tenant for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “actually incurred by Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance ItemsWork, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (includingcosts may include, without limitation, Larc improvements) which constitute standardcosts in connection with engineering and design, nonas well as construction-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion related costs and expenses up to a maximum aggregate amount of the Tenant Improvement Allowance. Tenant must submit a reimbursement request for payment of the Tenant Allowance in accordance with the provisions of this Paragraph 5 on or before the date that is not disbursed or allocated for disbursement by December 31twelve (12) months after the Effective Date, 2013, shall revert to Landlord and Tenant shall not be entitled to any credit, offset, or payment from Landlord for any portion of Tenant’s Allowance for which Tenant has not properly submitted a draw request in accordance with this Paragraph 5 on or before such date. Tenant shall promptly pay in full all costs and expenses associated with Tenant’s Work. Upon Substantial Completion of Tenant’s Work, and provided that no Event of Default exists under this Lease, Landlord shall reimburse Tenant the amount requested by Tenant in a single individual written draw request submitted by Tenant to Landlord within thirty (30) days of such request upon satisfaction of all of the following conditions: (a) all Tenant’s Work shall have no further rights been completed substantially in accordance with the approved Space Plans and Build-Out Plans; (b) Tenant shall have submitted a detailed written draw request to Landlord itemizing the cost of Tenant’s Work and certifying that all such Tenant Work has been completed in substantially in accordance with the approved Space Plans and Build-Out Plans and specifications therefor and in compliance with all applicable legal requirements; (c) Tenant shall have submitted to Landlord copies of paid invoices related to that portion of Tenant’s Work to be reimbursed together with lien waivers and releases from all material contractors, subcontractors, suppliers and other parties furnishing labor and/or material for such portion of Tenant’s Work; and (d) Tenant has commenced to operate its business at the Premises and delivered to Landlord a final, unconditional Certificate of Occupancy with respect theretoto the Premises duly issued by the Town of Exeter, New Hampshire. EXHIBIT AUpon completion of Tenant’s Work, Tenant shall deliver to Landlord a Certificate of Substantial Completion from Tenant’s architect certifying that all Tenant’s Work has been installed and completed substantially in accordance with the approved Space Plans and Build-Out Plans therefor and in compliance with all applicable legal requirements. Tenant shall be responsible for the performance of Tenant’s Work to completion and the payment of any costs and expenses related to Tenant’s Work which exceed the Tenant Allowance.

Tenant Improvement Allowance. Commencing (a) Landlord will grant Tenant an allowance ("Landlord's Allowance") of Fifty Dollars ($50.00) per Rentable Square Foot of Initial premises, including Vault Space and Lobby Space, to complete Tenant's initial improvements to the Premises ("Tenant Improvements" or "Work"), to cover moving and moving-related costs and architectural, consulting and engineering fees, to purchase furniture and equipment for the Initial Premises and to pay other costs and expenses of Tenant directly related to occupancy of or moving in to the Initial Premises. Tenant is entitled to tenant improvement and other allowances for Post-Occupancy Expansion Space as provided in Section 44 or First Offer Space as provided in Section 45. In the event that Tenant contracts with an entity other than Landlord for performance of January 1, 2011Tenant Improvements, Tenant shall be entitled conform with requirements for construction set forth in Exhibit E attached hereto. Landlord or Landlord's designee may, at Tenant's option, have the right to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, submit a proposed contract for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord , but Tenant will not be obligated to make disbursements select Landlord or Landlord's designee as its contractor. Payment of Landlord's Allowance to Tenant shall be made by Landlord only after the Low-Rise Access Date, except as set forth in Section 37(b), as work progresses (based on percentage completion) pursuant to this a draw schedule approved in advance by Landlord based on Tenant's presentation of invoices or lien waivers (on a 30 day trailing waiver basis so long as Landlord and any Mortgagee are insured against mechanic's liens through and including such 30 day period) and other documentation customarily required for disbursement of construction loans, including requirements of Landlord's construction lender. Tenant Work Letter or otherwise shall cause Chicago Title Insurance Company to apply the same procedures and standards as would be applied to an independent third party in connection the lien review procedure with Tenant’s construction of the respect to Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice despite its relationship to Tenant given concurrently and shall comply with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior such procedures. Notwithstanding anything herein to the end of the Lease Term or promptly following any earlier termination of this Leasecontrary, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect theretoobligation whatsoever to deposit any of its own funds into a construction escrow, if any is required by the construction lender for disbursement of the Landlord's Allowance. EXHIBIT ALandlord's failure to timely pay any portion of Landlord's Allowance shall constitute a Landlord default under Section 29 hereof, subject to the notice and cure periods provided in Section 29.

Tenant Improvement Allowance. Commencing as Landlord shall provide Tenant an allowance (The 'Tenant Improvement Allowance') which shall be applied to the cost of January 1, 2011, the construction of Tenant Improvements (the 'Tenant Improvements') in the Premises (excluding Tenant's trade fixtures) and which shall be in an amount of Thirty-Four Thousand Nine Hundred Forty-Two Dollars ($34,942) which is based on 17,471 rentable square feet multiplied by $2.00 per rentable square foot. Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, responsible for the costs relating to the design and construction cost of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the all Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum excess of the Tenant Improvement Allowance. All As used herein, the phrase 'cost of the construction of Tenant Improvements' shall mean and refer to all costs expended by Tenant relative to the construction of Tenant Improvements, which shall include, but shall not be limited to, costs of equipment, material and labor; contractor's field overhead and fees; cost of preparation of 1988 Southern California Chapter Initials ________ of the Society of Industrial and Office Realtors, Inc. (Multi-Tenant Gross Form) preliminary space plans and specifications and working drawings; governmental agency fees relating to said construction; costs of any requirements regarding construction which are imposed by any federal, state or local governmental entity or agency which are not reflected in the approved Plans and Specifications for the Tenant Improvements; sales and use taxes (but not real property taxes); permits; plan check fees; bonds; demolition; and other costs directly related to the construction of the Tenant Improvements. Upon completion of the Tenant Improvements, Tenant shall provide for Landlord a certification by Tenant of the cost of such construction and a copy of the final unconditional certificate of occupancy for the Premises issued by the city of San Diego and a certification by Tenant's general contractor that the Tenant Improvements for which have been constructed in a good and workmanlike manner in accordance with the Plans and Specifications as defined in subparagraph B, below, and that all sums owing to subcontractors, materialmen, laborers and other persons having mechanics' lien rights have been paid (or, if any payment is in good faith disputed, have been adequately bonded). Landlord shall reimburse Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms amount of the Lease; providedconstruction costs, howeverup to $34,942, Landlord may, by written notice to Tenant given concurrently with Landlord’s within twenty (20) days of receipt and approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior items listed above. Landlord may withhold up to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter fifteen percent (including, without limitation, Larc improvements15%) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance until thirty-five (35) days after the recordation of a notice of completion to help ensure that is not disbursed all mechanic's lien claims have been paid or allocated provided for. No part of the Tenant Improvement Allowance may be expended for disbursement by December 31, 2013, costs other than the costs of the construction of Tenant Improvements which shall revert to Landlord and be deemed Leasehold Improvements. Tenant shall have no further rights with respect thereto. EXHIBIT Abe permitted to remove all trade fixtures that they install into the Premises.

Tenant Improvement Allowance. Commencing as Subject to the terms and conditions of January 1this ----------------------------- paragraph below, 2011Landlord shall reimburse Tenant up to a maximum amount of Six hundred fourteen thousand, Tenant shall be entitled to use five hundred forty-one dollars and fifty cents ($614,541.50) (the “"Tenant Improvement Allowance”, as defined in Section 2 ") for (i) hard and soft costs of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements Improvements, including without limitation, all architectural and engineering fees incurred in connection therewith, sums payable to Landlord in connection therewith, and cabling and signange costs, and (ii) the brokerage fee payable to Colliers Damner Pike as a result of the Lease. Provided no Event of Default, or any Potential Default, shall then exist under the Lease from and after the date hereof, Landlord shall make advances to Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Allowance upon presentation of invoices from Tenant Improvements for which or the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under person performing the terms of work or rendering the Lease; providedservice and such reasonable supporting documentation as Landlord may require, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvementsmechanics' lien releases and certificates of payment issued by the Tenant's Architect and, if applicable, Tenant's designated representatives. Invoices that are submitted and approved by Landlord shall be paid on or before the fifteenth (15/th/) which constitute standardday of the following month. In addition, non-extraordinary improvements Tenant must provide Landlord with valid invoices prior to June 30, 1999 to be available for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of reimbursement under the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by Allowance, provided said date of June 30, 1999 may be extended to a maximum outside date of December 31, 20131999, shall revert to Landlord if Tenant is delayed on constructing its tenant improvement as a result of matters beyond Tenant's reasonable control and Tenant promptly notifies Landlord of such delay. Except as expressly provided above, Landlord shall have no further rights obligation to disburse any additional monies to Tenant, with respect thereto. EXHIBIT Ato the Tenant Improvement Allowance, the Tenant Improvements or the reimbursement under this Paragraph 3.

Tenant Improvement Allowance. Commencing In addition to any sums expended by Landlord on Phase 1 and Phase 2 of Landlord’s Work, as set forth in section 4 above, Landlord shall make available to Tenant a tenant improvement allowance of January 1up to $45,000 (the “Additional TI Allowance”), 2011such allowance to be used for the construction of fixed and permanent improvements in the Second Expansion Premises desired by and performed by Tenant (subject to Landlord’s supervision) and which improvements shall be of a fixed and permanent nature (the “Premises Improvements”). Tenant acknowledges that (i) Landlord’s prior written consent shall be required with respect to the Premises Improvements (which consent shall be granted or withheld in accordance with the standards established in Section 12 of the Lease), which also shall define any required restoration of the Second Expansion Premises at the end of the Term, and (ii) upon the expiration of the Term of the Lease, the Premises Improvements shall become the property of Landlord and may not be removed by Tenant. Notwithstanding anything to the contrary contained herein, the Additional TI Allowance shall not be used to purchase any furniture, personal property or other non-Building system materials or equipment, including, but not limited to, lab equipment, process equipment and other scientific equipment not incorporated into the Premises Improvements. All furniture, personal property or other non-Building system materials or equipment paid for by Tenant shall be the sole property of Tenant unless the same constitute Installations (as defined in Section 12 of the Lease). Except for the Additional TI Allowance, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 solely responsible for all of this Amendment, for the costs relating to of the design Premises Improvements. The Premises Improvements shall be treated as Alterations and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements undertaken pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms Section 12 of the Lease. Landlord shall have the right to approve the contractor for the Premises Improvements. Landlord shall not unreasonably delay its approval of such contractor. Landlord shall fund the Additional TI Allowance upon completion of the Premises Improvements and upon presentation to Landlord of a draw request containing unconditional lien waivers. Promptly following completion of the Premises Improvements and prior to funding by Landlord, Tenant shall provide to Landlord: (i) sworn statements setting forth the names of all contractors and subcontractors who did work on the Premises Improvements and final lien waivers from all such contractors and subcontractors; providedand (ii) “as built” plans for the Premises Improvements. Tenant acknowledges and agrees that, howevernotwithstanding anything to the contrary contained in the Lease, other than Phase 1 and Phase 2 of Landlord’s Work, Landlord mayrequires that, where such restoration has been agreed as set forth in the preceding paragraph, Tenant remove the [***] = Certain confidential information contained in this document, marked by written notice brackets, has been omitted and filed separately with the Securities and Exchange Commission pursuant to Tenant given concurrently with Landlord’s approval Rule 24b-2 of the “Final Working Drawings”Securities Exchange Act of 1934, as that term is defined in Section 3.3, below, require Tenant, amended. Confidential treatment has been requested with respect to the omitted portions. Premises Improvements and restore the Premises to its original condition prior to the end installation of the Lease Term Premises Improvements (“Premises Restoration”) at the expiration or promptly following any earlier termination of this the Lease. If, at Tenant’s expenseas of the expiration or earlier termination of the Term, to remove any Tenant has not removed the Premises Improvements and to repair any damage to completed the Premises and Building caused by such Restoration as required hereunder, Landlord may undertake the removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Improvements and the Premises Restoration. If Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion undertakes the removal of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31Premises Improvements and the Premises Restoration, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Apay to Landlord, within 10 days after written demand by Landlord, the costs and expenses incurred by Landlord to complete the removal of the Premises Improvements and Premises Restoration.

Tenant Improvement Allowance. Commencing as A. Subject to Tenant’s compliance with the provisions of January 1this Exhibit F, 2011, Landlord shall provide to Tenant shall be entitled to use an allowance in the amount of One Hundred Sixty Eight Thousand Twelve and 00/100 Dollars ($168,012.00) (the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for ) to construct and install only the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice Tenant shall have the right to Tenant given concurrently with Landlord’s approval utilize (i) up to Thirty Five Thousand Two and 50/100 Dollars ($35,002.50) of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to Tenant Improvement Allowance for the end purchase of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to furniture for the Premises (as evidenced by third party invoices for such furniture costs) and Building caused by such removal and return the affected portion of the Premises to (ii) all or a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed for the tenant improvements being constructed by Tenant at premises owned by affiliates of Landlord and to be leased by Tenant located at 1003 – 1005 and 0000 Xxxxxxxx Xxxxxx, Menlo Park, California, subject to the terms of the leases between Tenant and such affiliates of Landlord. The Tenant Improvement Allowance shall be used to design, prepare, plan, obtain the approval of, construct and install the Tenant Improvements and for no other purpose. Except as otherwise expressly provided herein, Landlord shall have no obligation to contribute the Tenant Improvement Allowance unless and until the Construction Documents have been approved by Landlord and Tenant has complied with all requirements set forth in Paragraph 4.C. of this Exhibit F. In addition to the foregoing, Landlord shall have no obligation to disburse all or allocated for disbursement by any portion of the Tenant Improvement Allowance to Tenant unless Tenant makes a progress payment request pursuant to the terms and conditions of Section 5.B. below prior to December 31, 20132012 (time being of the essence). The costs to be paid out of the Tenant Improvement Allowance shall include all reasonable costs and expenses associated with the design, shall revert to Landlord preparation, approval, planning, construction and installation of the Tenant shall have no further rights with respect thereto. EXHIBIT AImprovements (the “Tenant Improvement Costs”), including all of the following:

Tenant Improvement Allowance. Commencing as Notwithstanding anything to the contrary contained herein, provided Tenant is not then in default of January 1any of the terms, 2011conditions, Tenant and covenants of the Lease, Landlord shall be entitled contribute up to use $185,000.00 (the “Tenant Improvement Allowance”, as defined in Section 2 ) toward the cost of this Amendment, for the costs relating following improvements to the design Premises: new carpeting, painting, installation of new lighting, HVAC repairs/replacement (the “Tenant Work”), and construction of Tenant’s improvements or which are otherwise “architectural costs in connection with such improvements. The Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”)may not be used to pay any costs associated with any water availability charges or sewer availability charges. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise If any ADA upgrades are required in connection with Tenant’s construction the Tenant Work, Landlord shall be responsible for payment of the cost thereof, provided that Tenant has notified Landlord of such costs, and Landlord has approved such costs. In addition, Tenant shall either obtain a second bid for the Tenant Work, or engage in a value engineering process for its existing plan. If either of these results in costs savings, such that the cost of the Tenant Improvements or Work is less than $185,000, cost savings, up to $50,000.00, shall be equally divided between Landlord and Tenant; any total costs savings of greater than $50,000.00 shall be shared $25,000.00 to Tenant, and any remaining to Landlord1. The Tenant Improvement Allowance ItemsWork shall be performed by Tenant in accordance with the terms and provisions of this Lease, as defined belowand in a good and workmanlike manner by properly qualified and licensed personnel. All such work shall be diligently prosecuted to completion and shall comply with applicable laws. Upon Tenant’s presentation to Landlord, from time to time, but in no event later than May 1, 2011, of true and correct copies of construction contracts, copies of invoices, lien waivers, and such other documentation reasonably required by Landlord supporting the charges for completion of such Tenant Work, Landlord shall reimburse Tenant for the cost of the completed, in a total whole or in part, Tenant Work up to the amount which exceeds the sum of the Tenant Improvement Allowance. All Except as set forth above, Tenant Improvements for which the Tenant Improvement Allowance has been made available shall not be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises entitled to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, credit for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement used. Except as otherwise set forth herein, all costs of any Tenant Work in excess of the Tenant Improvement Allowance shall be paid by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Apromptly when due.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled Lessor hereby covenants and agrees to use provide Lessee with an improvement allowance in an amount equal to up to Two Thousand Four Hundred and No/100 Dollars ($2,400.00) (the “"Tenant Improvement Allowance”"), as defined which amount Lessor shall reimburse to Lessee for Lessee's costs and expenses incurred in Section 2 the installation of this Amendment, for a fence (the costs relating to "Fencing Work") around the design and construction of Tenant’s parking improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to upon receipt from Lessee of a Building standard general office conditionreceipt or receipts for such installation, together with any supporting documentation that Lessor shall reasonably require; provided, however, that Landlord shall not require Tenant (i) Lessor's obligations to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed reimburse Lessee for the Fencing Work pursuant to this Section 7 shall (x) be excused during and throughout any period during which Lessee is in material default under Paragraph 13.1 of the Lease, and (y) in no event be deemed an assumption by Lessor of any obligations to provide security services to the Premises or to ensure the safety or security of the parking improvements portion of the Premises, and (z) in no event be deemed a guaranty by Lessor of, or a representation by Lessor as to the quality or fitness of the Fencing Work or the compliance thereof with any applicable laws, codes, rules and/or regulations; and (ii) in the event that there are any outstanding (past due and payable) monies due to Lessor pursuant to the Lease at the time that Lessee submits its request for reimbursement of the Tenant Work Letter (includingImprovement Allowance, without limitationthen Lessor may, Larc improvements) which constitute standardat Lessor's sole discretion, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion elect to apply the amount of the Tenant Improvement Allowance requested to he reimbursed to Lessee (and reasonably evidenced by supporting invoices) to such outstanding monies, rather than paying such amount to Lessee, and Lessee hereby acknowledges and agrees that is not disbursed or allocated such application of the Tenant Improvement Allowance shall satisfy Lessor's obligations to provide the Tenant Improvement Allowance pursuant to this Section 7. Lessee hereby acknowledges and agrees that Lessee shall be responsible for disbursement by December 31, 2013, shall revert all costs of the Fencing Work in excess of the Tenant Improvement Allowance and Lessee hereby covenants and agrees to Landlord perform the Fencing Work at all times in accordance with Paragraphs 7.5 and Tenant shall have no further rights with respect thereto. EXHIBIT A49

Tenant Improvement Allowance. Commencing as Subject to the terms and ---------------------------- conditions set forth below, Landlord shall reimburse Tenant for Tenant's costs incurred to complete Tenant's Work (specifically excluding the cost of January 1any generator and any of Tenant's trade fixtures) in the amount of $2,173,590, 2011less (i) the pre-approved costs for Landlord's "pre-stock" doors; i.e., 50 wood doors/$13,000 total and two (2) pairs of glass doors/$11,904 total) and (ii) Landlord's reasonable out-of-pocket costs for its review of Tenant's preliminary plans, construction documents and final as-built Tenant's Work towards the cost of Tenant's Work ("Landlord's ---------- Contribution"), such costs to include architectural, engineering, ------------ expediting and other consulting fees, all building department permits and all costs of construction (including labor and materials). On a monthly basis, Landlord shall disburse to Tenant that portion of Landlord's Contribution equal to the amount set forth in Tenant's requisition. Each such disbursement shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall made by Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term calendar month in which a requisition has been submitted by Tenant, provided that Tenant has submitted such requisition on or promptly following any earlier termination before the 8th day of this Leasesuch calendar month. If Tenant's requisition shall be submitted to Landlord after the 8th day of a calendar month, at the disbursement with respect thereto shall be made by Landlord within five (5) business days after its receipt of such funds from its construction lender (but in no event later than the last day of the next succeeding calendar month). No advance shall be made by Landlord until its receipt of a request therefor from Tenant and the submission by Tenant of (i) a certificate signed by Tenant dated not more than ten (10) days prior to such request setting forth the sum then justly due to contractors, subcontractors, materialmen, engineers, architects and other persons who have rendered services or furnished materials in connection with Tenant’s expense, to remove any Tenant Improvements 's Work and to repair any damage (ii) lien waivers executed by such contractors having performed and received payment for their services to the Premises and Building caused by date of such removal and return requisition. In the affected event any portion of Landlord's Contribution remains unused following the Premises to a Building standard general office condition; providedcompletion of Tenant's Work, however, that Landlord such balance shall not require be applied by Tenant to remove upon termination or expiration its next installment(s) of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT ARent payable hereunder.

Tenant Improvement Allowance. Commencing Landlord agrees that Landlord shall pay to Tenant a tenant improvement allowance equal to the lesser of (i) the actual cost of Tenant Improvements (as of January 1hereinafter defined), 2011, Tenant or (ii) One Million and No/100 Dollars ($1,000,000.00) ("Tenant's Allowance") on the terms and conditions contained herein. Tenant's Allowance shall be entitled paid to use Tenant to reimburse Tenant for all of the “Tenant Improvement Allowance”, as defined in Section 2 actual hard and soft costs arising out of this Amendment, for the costs or relating to the design work platform and construction material handling system and equipment to be installed by Tenant in the Premises and related labor (including, but not limited to, (i) installation of Tenant’s improvements sprinklers and any additional fire prevention materials or which are otherwise “devices, (ii) installation of lighting, (iii) installation of a wireless network and related components, (iv) all fees, costs and expenses of all software to be used in conjunction with the Tenant Improvement Allowance items,” as that term is defined Improvements, (v) all wireless devices to be used in Section 2.2.1conjunction with the Tenant Improvements, below (vi) all fees, costs and expenses associated with designing the Tenant Improvements, (vii) all fees, costs and expenses associated with (a) application for any local, state or federal governmental permits, licenses, approvals or authorizations necessary to complete the Tenant Improvements and (b) approval, testing and/or installation relating to the Tenant Improvements) (collectively, the “"Tenant Improvements”)") and, provided Tenant complies with Section 13 of the Lease, approval for such Tenant Improvements shall not be unreasonably withheld, conditioned, or delayed. In no event Landlord agrees that Tenant shall Landlord not be obligated required to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of remove the Tenant Improvements at the expiration, or any Tenant Improvement Allowance Itemssooner termination, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms Term of the Lease; provided. Landlord shall reimburse Tenant for Tenant Improvements, howeverfrom time to time after the date hereof, within thirty (30) days after submission by Tenant to Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any paid invoices for Tenant Improvements and lien waivers from Tenant's general contractor. Tenant may request partial reimbursements for Tenant Improvements prior to repair any damage to the Premises and Building caused by completion of all Tenant Improvements. The aggregate amount of such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord reimbursements shall not require Tenant to remove upon termination or expiration exceed the total amount of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A's Allowance.

Tenant Improvement Allowance. Commencing as (1) Subject to the conditions of January 1this Construction Rider, 2011, Landlord shall pay to Tenant shall be entitled to use a tenant improvement allowance (the “Tenant Improvement Allowance”, as defined ) in Section 2 of this Amendment, for the costs relating amount equal to the design lesser of: (A) One Million and construction of 00/100 Dollars ($1,000,000.00), or (B) Tenant’s improvements or which are otherwise actual costs incurred in connection with the Tenant Improvements (the “Tenant’s Cost”), to be used by Tenant toward payment of a portion of the cost of the Tenant Improvements as set forth below. Any cost of the Tenant Improvements over and above the Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1Allowance, below (collectivelyif any, the “cost of any improvements not shown on the Plans and Specifications and the cost of any additional work required by Tenant, if any, shall be paid by Tenant. The Tenant’s Cost shall mean all hard and soft costs incurred by Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s design, construction and completion of the Tenant Improvements or any Tenant Improvement Allowance Itemsin accordance with the Plans and Specifications, as defined belowproperly payable to bona fide third party unrelated claimants, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) data and voice cabling, fire protection system equipment, energy management system equipment, space planning fees, architects’ and contractors’ fees, attorneys’ fees directly related to review of construction documents related to the Tenant Improvements, insurance and bond premiums, building permits, fees and licenses, but exclusive of any consulting fees other than to architects and contractors which constitute standardare not affiliated with Tenant and construction management fees, non-extraordinary improvements for ordinary officeand, laboratory and/or Larc uses in biotech facilitiesexcept as expressly set forth above, exclusive of equipment, trade and business fixtures and other personal property of Tenant. Any portion Landlord shall not be obligated to pay any part of the Tenant Improvement Allowance that is unless and until (as determined by Landlord in Landlord’s sole I-1345641.7 judgment) all of the terms, conditions, and covenants set out in this Construction Rider (and specifically the requirements of Section III(2) below) have been satisfied. Notwithstanding the foregoing, Tenant has entered into an agreement with Xxxx X. Xxxxx & Associates Architects, Inc. (the “Architect”) for space planning services related to the Tenant Improvements. Fifty percent (50%) of any space planning fees related to work completed by the Architect prior to Tenant’s execution and delivery of this Lease and which become due and payable by Tenant to Architect prior to Tenant’s execution and delivery of this Lease (the “Early Space Planning Fees”) shall be reimbursed by Landlord within thirty (30) days after Landlord’s receipt of any invoices therefor. However, in no event shall Landlord’s reimbursement of the Early Space Planning Fees exceed $5,000.00. The Early Space Planning Fees shall not disbursed be included as part of the Tenant’s Cost. Any space planning fees from the Architect related to work completed by the Architect after Tenant’s execution and delivery of this Lease or allocated for disbursement by December 31, 2013, which become due and payable after the Tenant’s execution and delivery of this Lease shall revert be included as part of Tenant’s Cost and may be reimbursed as part of the Tenant Improvement Allowance pursuant to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Athe terms of this Construction Rider.

Tenant Improvement Allowance. Commencing as The cost of January 1constructing the Tenant Improvements shall be paid by Landlord; provided, 2011however, if the amount charged to the Landlord by Landlord's general contractor (the "Contractor") for acquisition, construction and installation of the Tenant Improvements, plus architectural fees and permits relating to such construction and installation, is more than $216,702, Tenant hereby agrees to pay for all costs incurred in connection with the Tenant Improvements except for $216,702, which is the Landlord's entire monetary obligation for the Tenant Improvements ("Landlord's Portion"). In the event that the initial contract amount charged by the Contractor, plus architectural fees and permits, indicates that the total cost of the Tenant Improvements will be greater than Landlord's Portion, Tenant shall be entitled obligated to use make the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, first payments for the costs relating Tenant Improvements up to an amount equal to the design difference between the initial contract amount, plus architectural fees and construction permits, and the Landlord's Portion ("Tenant's Initial Payment"). Tenant shall make Tenant's Initial Payment based upon requisitions setting forth in reasonable detail the work performed and containing invoices, together with any other information reasonably requested by Tenant, and shall be paid by Tenant within ten (10) business days of receipt of each such requisition and other information. After Tenant has met its initial obligation by paying all of the Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively's Initial Payment, the “Tenant Improvements”). In no event Landlord shall Landlord be obligated to make disbursements pursuant pay the Landlord's Portion. In the event that change orders or other events cause the final cost of the Tenant Improvements to this be less than the sum of the Landlord's Portion and Tenant's Initial Payment, then Landlord shall reimburse Tenant Work Letter such excess up to the amount of Tenant's Initial Payment. In the event that change orders or other events cause the final cost of the Tenant Improvements to be more than the sum of the Landlord's Portion and Tenant's Initial Payment, then Tenant shall pay each such increase as soon as any such increase is determined in accordance with the same procedures as for the payment of Tenant's Initial Payment. Except as otherwise provided above, Tenant shall have complete responsibility for the cost of the Tenant Improvements and for the construction of any other improvements and alterations to the Premises in connection with Tenant’s 's occupancy thereof, Tenant agreeing to accept the same "AS IS", subject only to the construction of the Tenant Improvements. It is contemplated that the Contractor will be Bjxxx Xuilders, Inc. ("Bjxxx"). Landlord shall furnish Tenant with estimates of the costs of the various Tenant Improvements promptly after receipt thereof from Bjxxx xnd of Bjxxx'x xotal bid price for the construction of the Tenant Improvements. If Tenant is dissatisfied with such estimates or bid, Tenant may exercise its rights under subparagraph 3(d) above to request a change in the Plans. In addition, if Tenant believes that lower costs may be obtainable for the Tenant Improvements, Tenant may, by a written request received by Landlord within five (5) business days after the furnishing to Tenant any such estimate or bid (and prior to commencement of the Tenant Improvements) request that Landlord seek bids for the construction of the Tenant Improvements or any Tenant Improvement Allowance Itemsfrom other general contractors. Upon receipt of such request for rebidding and after consultation with Tenant, as defined below, in a total amount which exceeds Landlord shall request bids from not less than two (2) alternative general contractors for the sum construction of the Tenant Improvement Allowance. All Tenant Improvements for which and Landlord will consider the results of such bids in determining, along with the Tenant, the general contractor who will construct the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the LeaseImprovements; provided, however, Landlord may(1) may consider reasonable factors other than price in determining the general contractor to be selected, by written notice including but not limited to Tenant given concurrently with Landlord’s approval the willingness of the “Final Working Drawings”general contractor to execute the standard construction contract used by Landlord and its affiliates, and (2) may also permit Bjxxx xo reduce its bid. Tenant also agrees to accept any delays, costs and charges resulting from the requesting of such additional bids and use of any substituted general contractor or Bjxxx, if applicable, with the same force and effect as if Tenant had requested a change in the Plans as provided in subparagraph 3(d) above. Landlord shall execute a construction contract with Bjxxx xr other bidder, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expenseapplicable, to remove any Tenant Improvements and be the Contractor, with the Contract Sum to repair any damage to be based on the Premises and Building caused bid made by such removal and return the affected portion of the Premises to a Building standard selected general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Acontractor.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time allowance (the “"Tenant Improvement Allowance”, as defined ") in Section 2 the amount of this Amendment, Eight and 00/100 Dollars ($8.00) per square foot of Floor Area in the Premises for the costs relating to the design design, permitting and construction of the Tenant’s improvements 's Work (with the exception of the costs of any furniture, trade fixtures, equipment, personal property, signs or which are otherwise “architect's fees) (the "Permitted Tenant's Work Items"). Provided that Tenant is not in default under this Lease (beyond written notice and the expiration of the applicable cure period), the Tenant Improvement Allowance items,” as that term is defined shall be disbursed to Tenant within thirty (30) after completion of all of the following: upon Tenant's (a) delivery to Landlord of a copy of all invoices evidencing cost of Permitted Tenant's Work Items paid by Tenant totaling, or in Section 2.2.1, below (collectivelyexcess of, the “amount of the Tenant Improvements”)Improvement Allowance, (b) delivery to Landlord of a properly executed unconditional mechanic's lien releases in compliance with applicable Arizona statutes, (c) delivery to Landlord a copy of the Certificate of Occupancy for the Premises, (d) delivery to Landlord of a conformed copy of Tenant's recorded Notice of Completion, prepared and recorded in accordance with statutory requirements, (e) delivery to Landlord of a copy of all building permits with all sign-offs executed, and (f) substantial completion of Tenant's Work and opening for business to the public in the Premises. In no event Landlord shall Landlord only be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of from the Tenant Improvements or any Tenant Improvement Allowance to the extent costs are incurred by Tenant for Permitted Tenant's Work Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements Permitted Tenant's Work Items for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to . Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior shall not be entitled to the end of the Lease Term or promptly following any earlier termination of this Leasepayment of, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Leaseuse, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Leaseoffset against rental in the amount of, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that is not disbursed or allocated remaining following the completion of the Tenant's work. The cost of any work performed by Landlord for disbursement by December 31the benefit of Tenant, 2013if any, shall revert be deducted from the Tenant Improvement Allowance before the Tenant Improvement Allowance is paid to Landlord and Tenant shall have no further rights with respect theretoTenant. EXHIBIT AD SIGN CRITERIA EXHIBIT E GUARANTY OF LEASE [INTENTIONALLY OMITTED] EXHIBIT F USE RESTRICTIONS AND EXCLUSIVES

Tenant Improvement Allowance. Commencing A. Subject to Tenant’s compliance with the provisions of this Exhibit C, Landlord shall provide an allowance for the planning, designing, obtaining approvals of, permitting, and construction of the Tenant Improvements to be performed in the Leased Premises, as described in the Initial Plans and the Approved Final Drawings, in the amount of January 1, 2011, Tenant shall be entitled to use Seventy Two Thousand Seven Hundred and Twenty Dollars ($72,720.00) (the “Tenant Improvement Allowance”). Tenant shall not be entitled to any credit, as defined abatement or payment from Landlord in Section 2 the event that the amount of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” specified above exceeds the actual Tenant Improvement Costs. The Tenant Improvement Allowance shall only be used for tenant improvements typically installed by Landlord in buildings similar to that of which the Leased Premises are located which are generic in nature and that will likely be used by a subsequent tenant for normal use of the Leased Premises (referred to herein as that term is defined in Section 2.2.1, below (collectively, the “Tenant Generic Improvements”). In no event shall Landlord be obligated For example, Generic Improvements would include items such as new or relocated office demising walls and Building Standard electrical, any electronic security systems, plumbing and mechanical fixtures, equipment and distribution and telecommunications and network installations useable by any subsequent tenant, while items such as lab equipment and cabling and piping specific to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any business operations would not be considered Generic Improvements. The Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds shall be the sum of maximum contribution by Landlord for the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available Costs and shall be deemed Landlord’s property under subject to the terms provisions of the Lease; provided, however, Section 10 below. Landlord may, by written notice shall pay to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term all or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31in monthly progress payments as set forth in Section 5(B) below, 2013, shall revert to Landlord and Tenant shall have no further rights comply with respect theretoall time requirements hereunder. EXHIBIT AThe costs to be paid out of the Tenant Improvement Allowance shall include all reasonable costs and expenses associated with the design, preparation, approval, planning, construction and installation of the Tenant Improvements and shall include the cost of any signage permitted by this Lease (the “Tenant Improvement Costs”). The Tenant Improvement Allowance shall be the maximum contribution by Landlord for the Tenant Improvement Costs, and the disbursement of the Tenant Improvement Allowance is subject to the terms contained hereinbelow.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance in the amount of up to, but not exceeding One Hundred Dollars ($100.00) per rentable square foot of the Expansion Premises (the “Expansion Premises Allowance”) and Thirty Dollars ($30.00) per rentable square foot of the Existing Premises (together with the Expansion Premises Allowance, the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, ). The Tenant Improvement Allowance shall be used for the costs relating to the design design, permitting and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”); provided, however, that Landlord shall have no obligation to disburse all or any portion of the Tenant Improvement Allowance to Tenant unless Tenant makes a request for disbursement pursuant to the terms and conditions of Section 2.2 below prior to April 30, 2020. The Expansion Premises Allowance shall only be used for the costs relating to the Tenant Improvements in the Expansion Premises. The Existing Premises Allowance may be used for the costs relating to the Tenant Improvements in the Existing Premises and/or the Expansion Premises, in Tenant’s sole discretion. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that which is not disbursed or allocated used to pay for disbursement by December 31, 2013, shall revert to Landlord and the Tenant shall have no further rights with respect theretoImprovement Allowance Items (as such term is defined below). EXHIBIT A37849147v5

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a tenant improvement allowance (the “Tenant Improvement Allowance”, as defined "TENANT IMPROVEMENT ALLOWANCE") in Section 2 the amount of this Amendment, Four Million Three Hundred Forty-Five Thousand One Hundred Twenty-Three Dollars ($4,345,123.00) for the costs relating to the design and construction of Tenant’s 's improvements or (the "TENANT IMPROVEMENTS"). Tenant shall have the right to defer the construction of Tenant Improvements for space in the Building which are otherwise “Tenant Improvement Allowance items,” as elects not to initially build-out until no later than three (3) years after the Lease Commencement Date; however, (i) if Tenant elects to commence construction of Tenant Improvements for any space in the Building, such construction may not thereafter be deferred, and (ii) any such deferral shall be deemed a Tenant Delay so that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”)Lease Commencement Date shall not be delayed. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum Tenant Improvement Allowance (except as expressly contemplated by this Tenant Work Letter). Any portion of the Tenant Improvement AllowanceAllowance remaining after construction of the Tenant Improvements for the Building may be used by Tenant for Tenant Improvements for such Building before the first anniversary of the Lease Commencement Date for such Building; provided, however, Tenant shall have the right to transfer portions of the Tenant Improvement Allowance among the Building and Buildings 1 and 5 for Tenant Improvements and space planning costs only. Further, Tenant shall allocate and use a minimum Tenant Improvement Allowance for "hard costs" (i.e., costs incurred under the general contract with Contractor) of Tenant Improvements in an amount not less than Two Million Eight Hundred Thirty-Nine Thousand One Hundred Forty-Three Dollars ($2,839,143.00). All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property except as described under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination 8.5 of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as of January 1, 2011, A check for the Tenant Improvement Allowance in the amount set forth in the Special Lease Terms shall be entitled delivered by Landlord to Tenant following the completion of construction of the Initial Tenant Improvements on the Premises within the earlier to occur of: (i) (ii) five (5) business days following the release by Landlord's lender of loan funds borrowed by Landlord to perform the Tenant Improvements ("TI Loan Funds") or (ii) forty-five (45) days after the last of the following conditions has occurred: (A) Landlord has inspected the Premises and determined that Tenant’s Improvements are complete; (B) Tenant has obtained all required certificates of occupancy (or signed off building permits) from the City and County of San Francisco for use and operation of the “Premises and delivered copies of all such certificates to Landlord; (C) Tenant Improvement Allowance”has obtained an unconditional waiver and release on final payment in the form prescribed by California Civil Code Section 8138 from all persons or entities engaged in providing labor or materials in connection with the Tenant Improvements and delivered complete copies thereof to Landlord; (D) Tenant’s Architect has issued a certificate, as defined in a form reasonably acceptable to Landlord, certifying that the construction of the Tenant Improvements in the Premises has been substantially completed in accordance with the terms provided in Section 2 9 and Landlord has been provided with a copy thereof; (E) Tenant has recorded a notice of this Amendment, for completion in the costs Office of the Office of the Recorder of the County of San Francisco in accordance with California Civil Code Sections 8182 and 8184 and provided Landlord with a copy thereof; (F) Landlord has received copies of all receipted bills marked paid relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”); and (G) Tenant fulfills its obligations pursuant to Section 9 of the Lease. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, a disbursement in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements If despite Landlord's good faith, commercially reasonable efforts to obtain the timely release of the TI Loan Funds within forty five (45) days following Tenant's satisfaction of the above-stated conditions, Landlord is unable to obtain such release for which reasons outside of its reasonable control, Landlord shall not then be in default hereunder, provided that Landlord continues to use its good faith, commercially reasonable efforts to secure such TI Loan Funds as soon as possible thereafter. If Landlord is does not pay the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms on or before ninety (90) days following Tenant's satisfaction of the Lease; providedabove-stated conditions, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval then interest shall accrue on a daily basis against the outstanding balance of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the unpaid Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert at an interest rate equal to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT ALIBOR plus 3% per annum commencing on the sixtieth (60th) day following Tenant's satisfaction of the above-stated conditions.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Landlord shall provide an allowance to Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design planning, designing, and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any to be performed in the Leased Premises, as described in the Tenant Improvement Allowance Items, as defined belowPlans and Tenant Improvement Requirements, in a total the amount which exceeds of Three Million Four Hundred Seven Thousand One Hundred Eighty Dollars ($3,407,180.00) (the sum "Tenant Improvement Allowance"). In the event the costs of the Tenant Improvements will exceed the Tenant Improvement Allowance. All , Landlord shall provide Tenant Improvements for which with an additional allowance of up to Nine Hundred Seventy Three Thousand Four Hundred Eighty Dollars ($973,480.00.00) (the “Excess Tenant Improvement Allowance”); provided, however, in the event any such Excess Tenant Improvement Allowance has been made available funds are used by Landlord in the construction of the Tenant Improvements, such Excess Tenant Improvement Allowance funds used by Landlord in the construction of the Tenant Improvements shall be deemed amortized over the initial Lease Term (with interest thereon at Landlord’s property under the terms cost of funds) and shall be repaid to Landlord with payments to be made on a monthly basis commencing as of the LeaseCommencement Date; provided, however, Landlord may, agrees that Tenant shall have the right to prepay such Excess Tenant Improvement Allowance funds used by written notice to Tenant given concurrently with Landlord’s approval Landlord in the construction of the “Final Working Drawings”Tenant Improvements without interest or penalty). Tenant shall not be entitled to any credit, as abatement or payment from Landlord in the event that term is the amount of the Tenant Improvement Allowance exceeds the actual Tenant Improvement Costs (defined below). The Tenant Improvement Allowance, and the Excess Tenant Improvement Allowance (if applicable), shall only be used for the planning and construction of the Tenant Improvements in accordance with the terms of this Exhibit C. Landlord agrees that, subject to the terms of Section 3.3, 8 of this Exhibit C below, require Tenant, prior Landlord shall be solely responsible for the payment of all Tenant Improvement Costs incured by Landlord in the construction of the Tenant Improvements to the end extent in excess of the Lease Term or promptly following any earlier termination Tenant Improvement Allowance and, if applicable, the Excess Tenant Improvement Allowance. The costs to be paid out of this Leasethe Tenant Improvement Allowance and, at Tenant’s expenseif applicable, to remove any the Excess Tenant Improvement Allowance shall include all reasonable costs and expenses associated with the design, preparation, approval, planning, construction and installation of the Tenant Improvements and to repair any damage to (the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided"Tenant Improvement Costs"), however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion all of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Afollowing:

Tenant Improvement Allowance. Commencing as of January 1, 2011the Possession Date, Tenant shall be entitled to use the “"Tenant Improvement Allowance”", as defined in Section 2 5 of the Summary to this AmendmentLease, for the costs relating to the initial design and construction of Tenant’s improvements 's improvements, which are permanently affixed to the Premises or which are otherwise “"Tenant Improvement Allowance itemsItems,” " as that term is defined in Section 2.2.1, below (collectively, the “"Tenant Improvements"). In addition to the Tenant Improvement Allowance Landlord will reimburse Tenant in an amount not to exceed $5,360,530.00 (the "Base Building Allowance"), for actual costs incurred by Tenant in connection with certain infrastructure work (that is approved in advance by Landlord, such approval not to be unreasonably withheld, conditioned or delayed) (the “Base Building Work”) to be performed by Tenant with respect to the HVAC system, including, which may include (subject to Landlord’s approval, such approval not to be unreasonably withheld, conditioned or delayed), without limitation, installation, repair and/or replacement of HVAC systems, ductwork, serving a 1,000 Kw generator and related equipment and piping, architectural finishes, manufacturing and lab utility generation and distribution, power distribution, air filtration and purification, electrical work, and other systems and equipment that exclusively serve the Premises (the "Base Building Costs"), provided that Tenant separately accounts for such Base Building Costs. In connection with the foregoing, Landlord and Tenant agree to work in good faith with one another to develop a mutually agreeable scope of upgrades and modifications to the HVAC system serving the Building. The Base Building Allowance will be disbursed in the same manner as Landlord disburses the Tenant Improvement Allowance pursuant to this Tenant Work Letter. Such Base Building Allowance work shall (i) be constructed pursuant to the Tenant Work Letter, (ii) be deemed to be a part of the Tenant Improvements, and (iii) be deemed to be a component of the Tenant Improvement Allowance Items, but shall be accounted for and disbursed separately from the Tenant Improvement Allowance. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s 's construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance, Base Building Allowance and Additional TI Allowance (defined below). All Tenant Improvements that have been paid for which with or reimbursed from the Tenant Improvement Allowance, Base Building Allowance, Additional TI Allowance has been made available shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s 's approval of the “"Final Working Drawings”", as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly given following any earlier termination of this Lease, at Tenant’s 's expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilitiesremoval. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 20132022 (the “Allowance Deadline”), shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT AB -1- [Britannia Oyster Point I] [Nkarta, Inc.]

Tenant Improvement Allowance. Commencing as of January 1, 2011, Notwithstanding anything to the ---------------------------- contrary contained in the Lease: (i) Tenant shall be entitled to use the “a Tenant Improvement Allowance”Allowance in the amount of $3,458,229.00; (ii) Tenant acknowledges receipt of certain invoices sent by Xxxxxxxxxx X. Xxxxx of Landlord to Xxxxxxx Xxxxxxxxx of Tenant under cover of letter dated July 20, as defined in Section 2 2000 (the "Invoices"), which Invoices indicate that Landlord has performed certain improvement work on behalf of this Amendment, Tenant; (iii) Tenant and Landlord agree that the amount to be reimbursed by Tenant to Landlord for the costs such work relating to the design Invoices is $1,172,282.00 and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event such amount shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of offset against the Tenant Improvement Allowance. All ; (iv) Tenant Improvements for which shall have no further payment obligation to Landlord with respect to such work relating to the Tenant Improvement Allowance has been made available Invoices and such payment shall constitute full satisfaction of all amounts owed to Landlord as reimbursement of the costs of such work relating to such Invoices; and (v) the foregoing shall not be deemed Landlord’s property under a waiver of Tenant's right to receive the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion remainder of the Tenant Improvement Allowance that is in the amount of $2,285,947.00. Landlord shall wire the remaining Tenant Improvement Allowance set forth in (v) above to Tenant upon the closing of the sale of the Building by Landlord to 360networks inc. Landlord shall not disbursed have the right to perform any future work for or allocated on behalf of Tenant except as provided for disbursement by December 31in the Lease. Notwithstanding the foregoing, 2013, shall revert to Landlord Tenant expressly reserves all rights and Tenant shall have no further rights remedies with respect thereto. EXHIBIT Ato Landlord's performance of any Compliance Work or punch list items relating to Landlord's performance of the work relating to the Invoices.

Tenant Improvement Allowance. Commencing as of January 1, 2011In addition to the Space Plan Allowance described in Section 5.5 below, Tenant shall be entitled to use receive from Landlord a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the aggregate amount of up to, as defined in Section 2 but not exceeding, Nine Hundred Eighty-Nine Thousand Nine Hundred Seventy-Six Dollars ($989,976.00) (i.e., $38.00 per square foot of this Amendmentusable area of the Premises), to help Tenant pay for the costs relating to (collectively, the design “Tenant Improvement Costs”) of the design, permitting and construction of Tenant’s initial improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”). Notwithstanding the foregoing to the contrary, (a) with respect to each Construction Premises, Tenant may not use, and Landlord shall not be obligated to disburse, a portion of the Tenant Improvement Allowance to help Tenant pay for the Tenant Improvement Costs for such Construction Premises in an amount greater than $38.00 per square foot of usable area of such Construction Premises (each such portion of the Tenant Improvement Allowance referred to herein as the “TI Allowance Portion”), and (b) Landlord shall make each TI Allowance Portion available to help Tenant pay for the Tenant Improvement Costs for the Construction Premises applicable thereto commencing upon the following dates EXHIBIT D (each, a “TI Portion Availability Date”): (i) with respect to the Initial Premises only, upon the date of execution of this Lease; and (ii) with respect to each Construction Premises which is other than the Initial Premises, upon the date Landlord delivers possession of such Construction Premises to Tenant. In no event shall Landlord be obligated to make disbursements of the Tenant Improvement Allowance (or portions thereof) pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, Letter: (A) in a total amount which exceeds Nine Hundred Eighty-Nine Thousand Nine Hundred Seventy-Six Dollars ($989,976.00); and (B) with respect to each Construction Premises, (1) in an amount greater than the sum TI Allowance Portion applicable thereto, or (2) on a date prior to the TI Portion Availability Date applicable thereto. Except as otherwise provided in Section 2.1.2, below, Tenant shall not be entitled to receive as a cash payment or credit against Rent or otherwise any unused part of the TI Allowance Portion that is applicable to a particular Construction Premises that is not used to pay for the Tenant Improvement Allowance. All Tenant Improvements Costs for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice Items (as defined below) applicable and pertaining to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aparticular Construction Premises.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Landlord hereby grants to Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “a --------------------------------- Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1("Allowance") of Twenty-Five Thousand Dollars ($25,000), below (collectively, which Landlord shall pay to Tenant to reimburse Tenant for the “Cost of the Tenant Improvements”). In no event shall Landlord be obligated Prior to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s the commencement of construction of the Tenant Improvements or any Improvements, Tenant shall prepare and submit to Landlord for Landlord's reasonable approval a line item construction budget ("Budget") setting forth the costs of Tenant Improvements,. If the Budget (as approved by Landlord) exceeds the Allowance, the excess costs ("Excess Costs") shall be borne by Tenant. The Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum shall be promptly paid to Tenant upon completion of the Tenant Improvement AllowanceImprovements. All Tenant shall request reimbursement of said allowance in writing and provide receipts evidencing the completion of the construction, together with lien releases, appropriate building permits and any other documentation reasonably required by Landlord. If Tenant does not complete such Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 20131999, the allowance shall revert to expire and Landlord and Tenant shall have no obligation to further rights with respect theretosupply said allowance. EXHIBIT AIt is understood that the premises shall be cleaned and is being provided on an "as is" basis, provided that Tenant agrees to the "as is" basis immediately prior to its occupancy of the expansion area. By taking possession of the premises, Tenant acknowledges that it has examined the expansion premises and accepts the condition of the expansion premises as to "good working order" as used in this Third Amendment. All of the provisions of the Master Lease regarding acceptance of the premises shall apply to the expansion suites.

Tenant Improvement Allowance. Commencing as Landlord agrees to provide Tenant ---------------------------- with a "Tenant Improvement Allowance" for costs of January 1construction related to Tenant's Work of up to but not more than $14.00 per square foot ($386,078). Such payment shall be made within thirty (30) days following Landlord's receipt of third-party invoices for actual work performed in accordance with the plans and specifications approved by Landlord in advance, 2011together with "as-built" plan(s) showing the completion of such work, lien waivers reasonably satisfactory to Landlord from contractors or others performing the work or supplying the labor or material, and reasonable evidence that such work has been completed in accordance with all applicable laws, rules, regulations and ordinances. For the purposes hereof, "reasonable evidence" of completion shall be the issuance or a certificate of occupancy and any other certificates of compliance or completion required by applicable governmental authorities. Such work shall be performed by a contractor or contractors selected by Tenant and approved in writing by Landlord (such approval shall not be unreasonably withheld, conditioned or delayed). Tenant shall be entitled responsible for and shall pay directly and indemnify Landlord from and against any construction costs related to use the “Tenant Improvement Allowance”, as defined Tenant's Work in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum excess of the Tenant Improvement Allowance. All Tenant Improvements for which Notwithstanding anything herein to the contrary, Landlord agrees that, provided the Tenant Improvement Allowance has been made available exceeds the total proposed cost and expense of Tenant's construction work on the Premises ("Tenant's Improvement Costs"), on the basis of the construction budget formulated by Tenant and the Architect before the commencement of construction (as amended from time to time), and approved by Landlord (which approval shall not be unreasonably withheld or delayed), Tenant may add to Tenant's Improvement Costs and Landlord shall reimburse Tenant for, up to the limit of the Tenant Improvement Allowance, the cost of (i) fees of architects and construction managers incurred in connection with Tenant's Work, and (ii) furniture, fixtures and business equipment to be incorporated into the Premises, including by way of example and without limitation, office cubicles and voice and data cabling. To the extent that any such furniture, fixtures and equipment are paid for with the Tenant Improvement Allowance ("Financed FFE"), such Financed FFE shall be deemed Landlord’s the property under of Landlord for the terms duration of the initial five-year term of this Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, . If this lease shall terminate prior to the end expiration of the Lease Term or promptly initial five-year term, Tenant may remove the Financed FFE only after paying to Landlord the unamortized and unreimbursed cost of the Financed FFE, which shall be determined by multiplying the original cost thereof by a fraction, the numerator of which is the number of months remaining in the initial five-year term at the time of such termination and the denominator of which is 60. Provided there are funds available under the Tenant Improvement Allowance for any Financed FFE (based on the construction budget), then until the Tenant Improvement Allowance is reached, Landlord shall pay funds available from the Tenant Improvement Allowance for the Financed FFE to Tenant within ten (10) days following any earlier termination of this LeaseTenant's written request, at Tenant’s expense, which request shall include invoices and other reasonable substantiating documentation. If Tenant elects to remove any use the Tenant Improvements and to repair any damage Improvement Allowance for the Financed FFE to the Premises extent permitted herein, and Building caused by change orders or other events result in the Tenant Improvement Costs (inclusive of any Financed FFE) exceeding the Tenant Improvement Allowance, Tenant agrees to promptly pay to or reimburse Landlord for, as appropriate, any such removal and return the affected portion costs in excess of the Premises to a Building standard general office condition; providedTenant Improvement Allowance, however, it being the parties intention and understanding that Landlord shall not require be required to go "out-of-pocket" in excess of the Tenant Improvement Allowance. Tenant shall not be entitled to remove upon termination receive, by payment, credit or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Leaseotherwise, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance. The payment of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Abe subject to the following conditions:

Tenant Improvement Allowance. Commencing Except as set forth in this paragraph, no agreement of January 1Landlord to alter, 2011remodel, decorate, clean or improve the Premises, and no representation regarding the condition of the Premises has been made by or on behalf of Landlord or relied upon by Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 under or by reason of this Amendment, Tenant having agreed to accept the Premises for the costs relating Term in an “AS-IS, WHERE-LOCATED” condition. Notwithstanding the foregoing, and subject to Section 15 of the Lease, in connection with alterations or additions to the design Premises undertaken by Tenant as permitted by this Exhibit D (as defined here and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectivelybelow, the “Tenant ImprovementsWork”), Landlord shall pay that portion of the total cost thereof up to an amount equal to Five Thousand Seven Hundred Seventy-Two and 00/100 Dollars ($5,772.00) (the “Tenant Allowance”) (representing the product of $2.00 per rentable square foot contained in the Premises), which may be applied to the following “Tenant Work”: any construction-related costs (including, without limiting the foregoing, (a) costs related to labor and materials related to any demolition, construction, plumbing, carpeting, decorating, and electrical work; and (b) any so-called “soft costs” related to any construction-related costs). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction pay more than the actual out of pocket costs of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total Work up to the amount which exceeds the sum of the Tenant Improvement Allowance, and Tenant shall be responsible for all other costs thereof. All Tenant Improvements for which Landlord shall pay the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms to Tenant in one or more increments within thirty (30) days of receipt of a statement therefor from Tenant along with (i) copies of invoices showing payment by Tenant of the Lease; providedTenant Work then completed, however, Landlord may, and (ii) lien waivers from all contractors and subcontractors. The Tenant Allowance must be used by written notice to Tenant given concurrently with Landlord’s approval of on or before the “Final Working Drawings”, as date that term is defined in Section 3.3, below, require Tenant, prior to eighteen (18) months from the end of the Lease Term or promptly following any earlier termination date of this LeaseAmendment, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, retain any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect theretoAllowance. EXHIBIT A"E" LOCATION OF PARKING AREAS EXHIBIT "F" FORM OF CONFIDENTIALITY AGREEMENT THIS CONFIDENTIALITY AGREEMENT (this "Agreement"), dated as of ____________, is entered into by _______________, a ________("Tenant"), and ___________________________________ ("Auditor"), for the benefit of FSP __________________ Corp., a Delaware corporation ("Landlord").

Tenant Improvement Allowance. Commencing Landlord shall provide Tenant with a basic allowance for construction of Tenant's Improvements Work and to offset such other Tenant Improvement Costs as Tenant may incur in connection with this Lease in an amount determined by multiplying the sum of January 1, 2011, Tenant shall be entitled to use Thirty Five Dollars ($35.00) times the “number of square feet of Usable Area in the Premises as determined in accordance with Section 1.05 ("Tenant Improvement Allowance”, as defined "). All Tenant Improvement Costs in Section 2 excess of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” ("Tenant's Improvement Contribution") shall be paid by Tenant. The initial Tenant's Improvement Contribution shall be paid to Landlord fifteen (15) days after Tenant shall have approved a Cost Estimate or Revised Cost Estimate (as that each term is defined in Section 2.2.1, below (collectively, the “Work Letter) and Landlord and Tenant Improvements”)have thereafter agreed on an estimate of Tenant Improvement Costs. In no the event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any actual Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds Costs are less than the sum of the Tenant Improvement Allowance. All Allowance and Tenant's Improvement Contribution, then Landlord shall pay to Tenant Improvements for within ten (10) days after such determination the amount by which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion sum of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31and Tenant's Improvement Contribution exceeded the actual Tenant Improvement Costs; provided , 2013however, in no event shall the Landlord be required to pay an amount greater than the amount of Tenant's Improvement Contribution. The Tenant Improvement Allowance and Tenant's Improvement Contribution are herein collectively referred to as the "Tenant Improvement Fund". In no event, however, shall revert amounts paid for Tenant's moving costs from the Tenant Improvement Fund exceed Two Dollars ($2.00) per square foot of Usable Area in the Premises. In the event that the Tenant Improvement Costs exceed the Tenant Improvement Allowance, Tenant may elect by delivering written notice to Landlord within ten (10) days after the estimate of Tenant Improvement Cost is obtained pursuant to the Work Letter, to obtain from Landlord an additional allowance for the Tenant's Improvement Work ("Additional Tenant Improvement Allowance") in an amount not to exceed $5.00 per square foot of Usable Area in the Premises. The Additional Tenant Improvement Allowance shall be fully amortized at nine percent (9%) interest per annum on the unpaid balance over the initial Term of this Lease and shall be repaid by Tenant shall have no further rights with respect thereto. EXHIBIT Ato Landlord in equal monthly payments commencing on the Term Commencement Date as Additional Rent.

Tenant Improvement Allowance. Commencing as Landlord shall contribute to the costs and expenses of January 1all costs for the planning and design of Tenant Improvements, 2011including all permits, licenses and construction fees and constructing Tenant Work in an amount not to exceed the Tenant Improvement Allowance. If the final costs for Tenant Improvements exceed Tenant Improvement Allowance, Tenant shall be entitled to use responsible for such excess costs. If the “total cost of performing Tenant Improvements is less than the Tenant Improvement Allowance”, as defined in Section 2 portions of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” may be used towards Tenant's soft costs and existing Lease obligations in accordance with Section 1 of this Work Letter. Landlord shall pay the Tenant Improvement Allowance to Tenant consistent with the terms and conditions of this Section. After Tenant Improvements are complete (as provided under Section 11 hereof), Tenant may submit to Landlord a request in writing (the “Final Draw Request”) for the Tenant Improvement Allowance which request shall include: (a) “as-built“ drawings showing all of Tenant Improvements, (b) a detailed breakdown of Tenant's final and total construction costs, together with receipted invoices showing payment thereof, (c) a certified, written statement from the Architect that term is defined all of Tenant Improvements has been completed in Section 2.2.1accordance with the Drawings, below (collectivelyd) all required AIA forms, supporting final lien waivers, and releases executed by the Architect, General Contractor, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise Major Subcontractors and all subcontractors and suppliers in connection with Tenant Improvements, (e) a copy of a certificate of occupancy or amended certificate of occupancy required with respect to the Expansion Premises, if applicable, together with all licenses, certificates, permits and other government authorizations necessary in connection with Tenant Improvements and the operation of Tenant’s construction 's business from the Expansion Premises, and (f) proof reasonably satisfactory to Landlord that Tenant has complied with all of the conditions set forth in this Work Letter and has satisfactorily completed Tenant Improvements or any Tenant Improvement Allowance ItemsImprovements.” Upon Landlord's receipt and approval of the Final Draw Request, as defined below, in a total amount which exceeds Landlord shall pay the sum balance of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available Payment by Landlord shall be deemed Landlord’s property under made within thirty (30) days, unless Landlord notifies Tenant, in writing, of its rejection (and the terms reasons therefor) of any or all of the Lease; provided, howeverFinal Draw Request. To the extent Landlord does not so reject any portion of said Final Draw Request, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of shall timely pay the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior Draw Request. Notwithstanding the foregoing to the end of the Lease Term or promptly following any earlier termination contrary, but subject to Section 1 of this LeaseWork Letter, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to Landlord will pay the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion amount of the Tenant Improvement Allowance to Tenant in progress payments (not more often than monthly) after the applicable Actual Delivery Dates. Such progress payments will be made not later than thirty (30) days after receipt by Landlord from Tenant of copies of Tenant’s invoices from its Architect or General Contractor together with a certificate from Tenant indicating that is the work to which such invoices relate has been substantially completed and/or the materials to which such invoices relate have been installed in, or delivered to, the applicable portion of the Expansion Premises. Such progress payments will be made payable to Tenant and will be for the undisputed amount of the submitted invoices, less a ten percent (10%) retainage (which shall not disbursed or allocated for disbursement by December 31be released until such time as Landlord has received the Final Draw Request). As a condition precedent to Landlord’s issuing any such progress payment subsequent to the first such progress payment, 2013, shall revert Tenant will deliver to Landlord and Tenant shall have no further rights an original lien waiver from its general contractor waiving any claim for a mechanic’s or materialman’s lien with respect thereto. EXHIBIT Ato the labor and materials reflected in the invoices submitted for the immediately preceding progress payment.

Tenant Improvement Allowance. Commencing as Landlord agrees to provide to Tenant an allowance with respect to the Phase I Premises equal to $45.00 per square foot of January 1, 2011, Tenant shall be entitled to use net rentable area based on the number of square feet in the Phase I Premises (the “Phase I Tenant Improvement Allowance”). The Phase I Tenant Improvement Allowance may be applied by Tenant to the cost of (a) (i) all space planning, (ii) Phase I Tenant Construction Documents (as defined in Section 2 Exhibit D), (iii) contractor costs, (iv) construction management fees for Tenant’s selected construction manager, and (v) Tenant Work (collectively, the “Phase I Construction Costs”), (b) telecommunications/data costs, (c) furniture expenses and (d) relocation and moving expenses ((b), (c) and (d) being known as the “Phase I Soft Costs”). Any unused portion of the Phase I Tenant Improvement Allowance up to $15.00 per square foot of net rentable area of the Phase I Premises (the “Phase I Soft Costs Improvement Cap”) may be (i) applied as a credit to the first installment(s) of Base Rental coming due for the Phase I Premises under this Amendmentlease or (ii) at Tenant’s sole discretion, for any purposes related to Tenant’s occupancy of the costs relating Premises. If Tenant has not fully utilized the Phase I Tenant Improvement Allowance as set forth herein within twelve (12) months after the Phase I Rent Commencement Date, any remaining balance of the Phase I Tenant Improvement Allowance (up to the design Phase I Soft Costs Improvement Cap and after deducting any portion of the Phase I Tenant Improvement Allowance utilized for the Phase I Soft Costs) will be credited to the next Base Rental due hereunder, and any additional amounts not otherwise applied as hereinabove described shall be added to the Phase II Tenant Improvement Allowance. Tenant shall manage the construction of the Premises and there shall be no construction management fee paid to Landlord. Prior to commencement of construction of Tenant’s improvements or which are otherwise “to the Phase I Premises, Tenant shall furnish Landlord with an estimate of Tenant’s total Phase I Construction Costs. Landlord shall pay Tenant the Phase I Tenant Improvement Allowance items,” based on submission of an invoice by Tenant to Landlord no later than the 15th day of each month. Each invoice shall list Phase I Construction Costs which Tenant has previously paid along with copies of each paid invoice, copies of each check given in payment of such invoices, and lien waivers from each entity (interim lien waivers are permitted for interim draws and final lien waivers are required for final draw) and Landlord shall pay ninety percent (90%) of each invoice. Landlord will pay Tenant ninety percent (90%) of each received invoice by the 20th day of the following month for each Tenant invoice submitted until Landlord shall have paid to Tenant ninety percent (90%) of the full amount of the Phase I Tenant Improvement Allowance. The final ten percent (10%) of the Phase I Tenant Improvement Allowance shall be paid upon the last to occur of the following: (a) substantial completion of the improvements to the Phase I Premises as contemplated by the Phase I Construction Documents and issuance of a temporary or permanent Certificate of Occupancy with respect thereto, or (b) submission of paid invoices and final lien waivers evidencing payment in full by Tenant of all Phase I Construction Costs. Tenant shall be responsible for payment of all Phase I Construction Costs exceeding the Phase I Tenant Improvement Allowance. Alternatively to payment of the Phase I Tenant Improvement Allowance to Tenant as aforesaid, upon Tenant’s written request and express direction, Landlord shall pay such invoiced amounts directly to the appropriate vendors (up to but not in excess of five (5) such vendors per month). In the event that term is Landlord shall fail to remit to Tenant (or Tenant’s vendors, as directed by Tenant pursuant to the terms of this Exhibit C-1) the Phase I Tenant Improvement Allowance as hereinabove described, and in the further event that such failure shall continue for fifteen (15) days following Tenant’s delivery of written notice to Landlord (in addition to Tenant’s delivery of invoices and other documentation as required above), then, in addition to, and without limitation of, any other rights and remedies that Tenant may have under this lease, Tenant shall have the right to offset the cost of any Phase I Construction Costs and other permissible expenses incurred by Tenant pursuant to the terms of this Exhibit C-1 against its next due installments of Base Rental for the Phase I Premises until Tenant shall have been fully reimbursed therefor. XXXXXXX X-0 XXXXX XX TENANT IMPROVEMENT ALLOWANCE Landlord agrees to provide to Tenant an allowance with respect to the Phase II Premises equal to $45.00 per square foot of net rentable area based on the number of square feet in the Phase II Premises (the “Phase II Tenant Improvement Allowance”). The Phase II Tenant Improvement Allowance may be applied by Tenant to the cost of (a) (i) all space planning, (ii) Phase II Tenant Construction Documents (as defined in Section 2.2.1Exhibit D-l), below (iii) contractor costs, (iv) construction management fees for Tenant’s selected construction manager, (v) Tenant Work, and (vi) Phase I Construction Costs (collectively, the “Tenant ImprovementsPhase II Construction Costs”), (b) telecommunications/data costs, (c) furniture expenses and (d) relocation and moving expenses ((b), (c) and (d) being known as the “Phase II Soft Costs”). In no event shall Landlord Any unused portion of the Phase II Tenant Improvement Allowance up to $15.00 per square foot of net rentable area of the Phase II Premises (the “Phase II Soft Costs Improvement Cap”) may be obligated (i) applied as a credit to make disbursements pursuant to the first installment(s) of Base Rental coming due for the Phase II Premises under this Tenant Work Letter lease or otherwise in connection with (ii) at Tenant’s sole discretion, for any purposes related to Tenant’s occupancy of the Premises. If Tenant has not fully utilized the Phase II Tenant Improvement Allowance as set forth herein within twelve (12) months after the Phase II Rent Commencement Date, any remaining balance of the Phase II Tenant Improvement Allowance (up to the Phase II Soft Costs Improvement Cap and after deducting any portion of the Phase II Tenant Improvement Allowance utilized for the Phase II Soft Costs) will be credited to the next Base Rental due hereunder, and any additional amounts not otherwise applied as hereinabove described shall be added to the Phase III Tenant Improvement Allowance. Tenant shall manage the construction of the Premises and there shall be no construction management fee paid to Landlord. Prior to commencement of construction of Tenant’s improvements to the Phase II Premises, Tenant Improvements or any shall furnish Landlord with an estimate of Tenant’s total Phase II Construction Costs. Landlord shall pay Tenant the Phase II Tenant Improvement Allowance Itemsbased on submission of an invoice by Tenant to Landlord no later than the 15th day of each month. Each invoice shall list Phase II Construction Costs which Tenant has previously paid along with copies of each paid invoice, copies of each check given in payment of such invoices, and lien waivers from each entity (interim lien waivers are permitted for interim draws and final lien waivers are required for final draw) and Landlord shall pay ninety percent (90%) of each such invoice. Landlord will pay Tenant ninety percent (90%) of each received invoice by the 20th day of the following month for each Tenant invoice submitted until Landlord shall have paid to Tenant ninety percent (90%) of the full amount of the Phase II Tenant Improvement Allowance. The final ten percent (10%) of the Phase II Tenant Improvement Allowance shall be paid upon the last to occur of the following: (a) substantial completion of the improvements to the Phase II Premises as contemplated by the Phase II Construction Documents and issuance of a temporary or permanent Certificate of Occupancy with respect thereto, or (b) submission of paid invoices and final lien waivers evidencing payment in full by Tenant of all Phase II Construction Costs. Tenant shall be responsible for payment of all Phase II Construction Costs exceeding the Phase II Tenant Improvement Allowance. Alternatively to payment of the Phase II Tenant Improvement Allowance to Tenant as aforesaid, upon Tenant’s written request and express direction, Landlord shall pay such invoiced amounts directly to the appropriate vendors (up to but not in excess of five (5) such vendors per month). In the event that Landlord shall fail to remit to Tenant (or Tenant’s vendors, as defined belowdirected by Tenant pursuant to the terms of this Exhibit C-2) the Phase II Tenant Improvement Allowance as hereinabove described, and in the further event that such failure shall continue for fifteen (15) days following Tenant’s delivery of written notice to Landlord (in addition to Tenant’s delivery of invoices and other documentation as required above), then, in a total amount which exceeds addition to, and without limitation of, any other rights and remedies that Tenant may have under this lease, Tenant shall have the right to offset the cost of any Phase II Construction Costs and other permissible expenses incurred by Tenant pursuant to the terms of this Exhibit C-2 against its next due installments of Base Rental for the Phase II Premises until Tenant shall have been fully reimbursed therefor. XXXXXXX X-0 XXXXX XXX TENANT IMPROVEMENT ALLOWANCE Landlord agrees to provide to Tenant an allowance with respect to the Phase III Premises (the “Phase III Tenant Improvement Allowance”) equal to the sum of the following: $45.00 per square foot of net rentable area based on the number of square feet in the Phase III Premises times a fraction, the numerator of which is the number of full calendar months remaining in the Term after the Phase III Commencement Date and the denominator of which is 180 (the “Phase III Proration”). The Phase III Tenant Improvement Allowance may be applied by Tenant to the cost of (a) (i) all space planning, (ii) Phase III Tenant Construction Documents (as defined in Exhibit D-2), (iii) contractor costs, (iv) construction management fees for Tenant’s selected construction manager, (v) Tenant Work, (vi) Phase I Construction Costs, and (vii) Phase II Construction Costs (collectively, the “Phase III Construction Costs”), (b) telecommunications/ data costs, (c) furniture expenses and (d) relocation and moving expenses ((b), (c) and (d) being known as the “Phase III Soft Costs”). Any unused portion of the Phase III Tenant Improvement Allowance up to $15.00 per square foot of net rentable area of the Phase III Premises (the “Phase III Soft Costs Improvement Cap”) may be (i) applied as a credit to the first installment(s) of Base Rental coming due for the Phase III Premises under this lease or (ii) at Tenant’s sole discretion, for any purposes related to Tenant’s occupancy of the Premises. If Tenant has not fully utilized the Phase III Tenant Improvement Allowance as set forth herein within twelve (12) months after the Phase III Rent Commencement Date, any remaining balance of the Phase III Tenant Improvement Allowance (up to the Phase III Soft Costs Improvement Cap and after deducting any portion of the Phase III Tenant Improvement Allowance utilized for the Phase III Soft Costs) will be credited to the next Base Rental due hereunder. Tenant shall manage the construction of the Premises and there shall be no construction management fee paid to Landlord. Prior to commencement of construction of Tenant’s improvements to the Phase III Premises, Tenant shall furnish Landlord with an estimate of Tenant’s total Phase III Construction Costs. Landlord shall pay Tenant the Phase III Tenant Improvement Allowance based on submission of an invoice by Tenant to Landlord no later than the 15th day of each month. Each invoice shall list Phase III Construction Costs which Tenant has previously paid along with copies of each paid invoice, copies of each check given in payment of such invoices, and lien waivers from each entity (interim lien waivers are permitted for interim draws and final lien waivers are required for final draw) and Landlord shall pay ninety percent (90%) of each such invoice. Landlord will pay Tenant ninety percent (90%) of each received invoice by the 20th day of the following month for each Tenant invoice submitted until Landlord shall have paid to Tenant ninety percent (90%) of the full amount of the Phase II Tenant Improvement Allowance. All Tenant Improvements for which The final ten percent (10%) of the Phase III Tenant Improvement Allowance has been made available shall be deemed Landlordpaid upon the last to occur of the following: (a) substantial completion of the improvements to the Phase III Premises as contemplated by the Phase III Construction Documents and issuance of a temporary or permanent Certificate of Occupancy with respect thereto, or (b) submission of paid invoices and final lien waivers evidencing payment in full by Tenant of all Phase III Construction Costs. Tenant shall be responsible for payment of all Phase III Construction Costs exceeding the Phase III Tenant Improvement Allowance. Alternatively to payment of the Phase III Tenant Improvement Allowance to Tenant as aforesaid, upon Tenant’s property under written request and express direction, Landlord shall pay such invoiced amounts directly to the appropriate vendors (up to but not in excess of five (5) such vendors per month). In the event that Landlord shall fail to remit to Tenant (or Tenant’s vendors, as directed by Tenant pursuant to the terms of this Exhibit C-3) the Lease; providedPhase III Tenant Improvement Allowance as hereinabove described, however, Landlord may, by and in the further event that such failure shall continue for fifteen (15) days following Tenant’s delivery of written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined Landlord (in Section 3.3, below, require Tenant, prior addition to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expensedelivery of invoices and other documentation as required above), to remove any Tenant Improvements then, in addition to, and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Leasewithout limitation of, any other rights and remedies that Tenant Improvements constructed pursuant to may have under this Tenant Work Letter (includinglease, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect theretothe right to offset the cost of any Phase III Construction Costs and other permissible expenses incurred by Tenant pursuant to the terms of this Exhibit C-3 against its next due installments of Base Rental for the Phase III Premises until Tenant shall have been fully reimbursed therefor. EXHIBIT AXXXXXXX X

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant Landlord shall be entitled provide an amount not to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which exceed the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under toward the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently Improvement Items in accordance with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, 2.3.2 below, require TenantExcept as provided in this Section 2.2.1, prior Tenant shall not be entitled to the end receive any portion of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, Improvement Allowance not actually expended for Tenant Improvement Items nor shall Tenant have any right to remove apply any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that as a credit against Rent or any other obligations of Tenant under the Lease, as set forth below. Upon the occurrence of the date which is twelve months after the Commencement Date, any remaining portion of the Tenant’s Improvement Allowance not disbursed or allocated for disbursement Tenant Improvement Items shall be retained by December 31Landlord; provided, 2013, shall revert however that notwithstanding the foregoing provided that (i) no Event of Default then exists; and (ii) the Tenant Improvement Items have been substantially completed and Tenant has delivered to Landlord a sworn statement to Landlord which identifies all agents, contactors and materials suppliers engaged by Tenant shall have no further rights in connection with respect thereto. EXHIBIT Athe Tenant Improvements and sworn statements and lien waivers from such agents, contractor and materials suppliers, such statements and lien waivers all in such form as reasonably required by Landlord, then, provided Tenant makes such request to Landlord on or before the date which is fifteen (15) months after the Lease Commencement Date, Tenant may apply (x) the Tenant Improvement Allowance towards architectural, engineering, space planning, furniture, moving or any other expenses reasonably incurred by Tenant in connection with its relocation to the Premises, and (y) up to $490,464.00 of the unused Tenant Improvement Allowance as a credit against Base Rent or any other obligations of Tenant under the Lease until such credit is exhausted.

Tenant Improvement Allowance. Commencing as of January 1As an inducement for Tenant to enter into and faithfully perform under this Lease, 2011, Tenant Landlord shall be entitled to use pay an allowance (the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating ) equal to the design and construction of Tenant’s improvements or which are otherwise “$130,440.00. The Tenant Improvement Allowance items,” shall be used by Tenant as that term is defined set forth in Section 2.2.1, below (collectively, the “Tenant Improvements”)12.2.17 of Exhibit C attached here and made a part hereof. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any The Tenant Improvement Allowance Items, shall be payable directly to Tenant within thirty (30) days of submission to Landlord of (i) invoices from Tenant’s contractor(s) performing such work; (ii) lien waivers from Tenant’s contractors indicating payment for all services and materials relating to such improvements and to the Premises; and (iii) such other documents as defined below, in a total amount which exceeds the sum of Landlord may reasonably request. Tenant shall not be permitted to submit more than one (1) such request per calendar month for reimbursement from the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance which remains unused by Tenant as of the date that is not disbursed or allocated one hundred and twenty (120) days after the issuance of a Certificate of Occupancy for disbursement by December 31, 2013the Premises, shall revert to be deemed waived by Tenant and Landlord and Tenant shall have no further rights obligation with respect thereto. EXHIBIT AIn the event Landlord fails or is unable to pay the Tenant Improvement Allowance, or any portion thereof, to Tenant as set forth in Exhibit C, Tenant shall have the right to apply the amount of such portion of the Tenant Improvement Allowance against the next installment of Basic Rent due under the Lease; provided, however, in the event there exists a dispute between Landlord and Tenant with respect to any request for reimbursement as described herein, Tenant shall not be permitted to apply any such amounts against any Rent or other charges due under this Lease until the dispute is resolved.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be Lessee is entitled to use a one-time tenant improvement allowance (the “"Tenant Improvement Allowance”, as defined ") in Section 2 the amount of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Two Hundred Thousand Dollars ($200,000.00). The Tenant Improvement Allowance items,” as that term is defined may be used for all actual hard costs incurred by Lessee in Section 2.2.1, below (collectively, constructing the “Tenant Improvements”). In no event shall Landlord will Lessor be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise for any costs in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum excess of the Tenant Improvement Allowance. All Tenant Improvements No credit will be given for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance. Upon substantial completion of the Tenant Improvements, but in no event later than December 1, 2004, Lessee will deliver the following documentation to Lessor: (i) detailed invoices for the work performed, (ii) evidence that Contractor and any subcontractors have been paid, (iii) final unconditional mechanics lien releases, (iv) a final or conditional certificate of occupancy from the City of South San Francisco, and (v) a Notice of Completion filed with the County of San Mateo (the receipt of all five of which shall conclusively be deemed to constitute substantial completion of the Tenant Improvements). Lessor will have ten (10) business days from receipt of the information to review and reasonably approve the invoices and to inspect the work performed. Unless, Lessor reasonably disapproves the invoices and or the work performed and provides detailed written notice to Lessee specifying the reasons for such disapproval within said ten (10) business day review period, Lessor shall reimburse Lessee up to the amount of the Tenant Improvement Allowance. Lessor will not be obligated to pay the Tenant Improvement Allowance that to Lessee if (i) Lessee is in material default under the Lease beyond the expiration of all applicable notice and cure periods or (ii) Lessee does not disbursed complete the Tenant Improvements and submit all of the documentation required for reimbursement prior to December 1, 2004. Lessor shall not be obligated to pay the Tenant Improvement Allowance if the Tenant Improvements are not substantially completed prior to the Completion Date, unless such failure to complete arises from the action or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Ainaction of Lessor.

Tenant Improvement Allowance. Commencing as Subject to Tenant’s satisfaction or Landlord’s waiver of January 1, 2011the Contingency pursuant to Section 2.1.1 of the Lease, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the amount of up to, as defined in Section 2 but not exceeding $45.00 per rentable square foot of this Amendmentthe Premises (i.e., up to $976,365.00 based on 21,697 rentable square feet of the Premises), to help Tenant pay for the costs relating to of the design design, permitting and construction of Tenant’s initial improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”); provided, however, that Landlord shall have no obligation to disburse all or any portion of the Tenant Improvement Allowance to Tenant unless Tenant makes a request for disbursement pursuant to the terms and conditions of Section 2.2 below prior to that date which is twelve (12) months after the Lease Commencement Date. In addition, Tenant shall be entitled to a one-time space plan allowance (the “Space Plan Allowance”) in the amount of up to, but not exceeding, $0.15 per rentable square foot of the Premises (i.e., up to $3,254.55 based on 21,697 rentable square feet of the Premises), to help reimburse Tenant for the costs of the preparation of the Final Space Plan (as defined below), which Space Plan Allowance shall not be contingent on Tenant’s satisfaction or Landlord’s waiver of the Contingency. Landlord shall disburse the Space Plan Allowance to Tenant to help reimburse Tenant for the costs of the preparation of the Final Space Plan within thirty (30) days after Landlord’s receipt of Tenant’s written notice requesting such disbursement accompanied by all receipts and invoices evidencing all costs of preparation of the Final Space Plan actually paid by Tenant; provided, however, Landlord shall have no obligation to disburse any portion of the Space Plan Allowance for any such Final Space Plan costs unless Landlord receives such written request for reimbursement by that date which is three (3) months after the Lease Commencement Date. In addition, in no event shall Tenant be entitled to receive as a credit, abatement or payment from Landlord any portion of the Space Plan Allowance that is not used to reimburse Tenant for any such Final Space Plan costs (such remaining unused portion shall revert to and shall be retained by Landlord). Other than the Space Plan Allowance described hereinabove, in no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that which is not disbursed or allocated used to pay for disbursement by December 31, 2013, shall revert to Landlord and the Tenant shall have no further rights with respect thereto. EXHIBIT AImprovement Allowance Items (as defined below).

Tenant Improvement Allowance. Commencing as Landlord shall contribute to any alterations, additions and improvements made to the Property by Tenant (the "Tenant Improvements") up to a maximum of January 1One Hundred Eighty Seven Thousand Five Hundred and No/100 Dollars ($187,500.00) (the "Allowance") over the Lease Term, 2011which Tenant Improvements shall be constructed in accordance with the terms of this Lease, including, but not limited to, the terms of Article Six hereof and this Article Fifteen. Payment of the Allowance shall be in installments as, when and if the Tenant Improvements are completed, and within twenty-one (21) days after presentation to and approval of paid invoices and receipts by Landlord. All requests for payments of the Allowance shall be accompanied by lien releases from all contractors and subcontractors for work performed and materials provided and, if applicable, the certificate of completion from the supervising architect. In the event of any mechanic's or other lien, claim or encumbrance arising out of or in connection with the Tenant Improvements being asserted against the Property, Landlord, or Landlord's property, Tenant shall be entitled discharge in full said lien, claim or encumbrance within fifteen (15) days following notice thereof. If Tenant fails to use discharge the “lien within said fifteen (15) day period, Landlord may, at its option, discharge same and, upon Landlord's demand, Tenant Improvement Allowance”shall promptly reimburse Landlord for all costs incurred in discharging such lien. Tenant shall indemnify and hold harmless Landlord from and against any and all losses, as defined in Section 2 damages, costs (including costs of this Amendmentsuit and attorneys fees), liabilities, or causes of action for injury to or death or any person, for the costs relating damage to the design any property, and construction for mechanics', materialmen's or other liens or claims arising out of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s the construction of the Tenant Improvements Improvements. Nothing contained herein shall constitute an agreement to subject the fee or leasehold interest in the Property to any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowancelien or other encumbrance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior Notwithstanding anything to the end of the Lease Term or promptly following any earlier termination of contrary contained herein, should Tenant be in material default under this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion no payment of the Premises to a Building standard general office condition; provided, however, that Landlord Allowance shall be made by Landlord. Tenant shall not require Tenant take any action which would cause any violation of applicable laws to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aoccur

Tenant Improvement Allowance. Commencing as of January 1, 2011, Landlord shall reimburse Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating up to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance, provided that Landlord may withhold the amount of $10,000.00 to ensure completion of filling the existing pit on the Premises. All Tenant’s preliminary architectural/construction/space plan documents, prepared by Tenant Improvements or contracted for directly by Tenant (the “Space Plan Documents”), have been provided to Landlord, and Tenant has obtained cost estimates to construct Tenant’s Work pursuant to the Space Plan Documents (the “Estimated Construction Costs”). Within fifteen (15) days after the Date of Lease, Tenant shall submit to Landlord two (2) copies of the complete plans and specifications (the “Tenant’s Plans”) for the work outlined in the Space Plan Documents. Tenant’s Plans shall include the Landlord’s Work and any additional work to be completed by Tenant (the “Tenant’s Work”). Within five (5) days after Landlord’s receipt of Tenant’s Plans, Landlord shall notify Tenant of any failures of the Tenant’s Plans to meet with Landlord’s approval. Tenant shall, within five (5) days after receipt of any such notice, cause the Tenant’s Plans to be revised to the extent necessary to obtain Landlord’s approval and to be resubmitted for Landlord’s approval. Both Landlord and Tenant acknowledge and agree that revisions to Tenant’s Plans must be reasonable in the context of meeting the needs of Tenant’s operations in the Premises. When Landlord has approved the original or revised Tenant’s Plans, Landlord shall initial and return one (1) set of approved Tenant’s Plans (the “Approved Plans”) to Tenant within two (2) days of such approval. Tenant shall not commence Tenant’s Work until Landlord has approved Tenant’s Plans, which approval shall not be unreasonably withheld. If the Estimated Construction Costs are greater than the Tenant Improvement Allowance has been made available Allowance, Tenant shall be deemed responsible for such excess amount, or at its option, Tenant may reduce the scope of the Space Plan Documents to reduce the Estimated Construction Costs. Any additional improvement work required by Tenant, or change orders that increase the cost of Landlord’s property under Work or the terms Estimated Construction Costs, or actual and direct costs of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval build out of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expensePlans, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion excess of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013Allowance, shall revert be the sole financial responsibility of the Tenant (“Tenant’s Cost of Construction”). In consideration of the $50,000.00 for the Tenant Improvement Allowance, in addition to Landlord and the other work contemplated, Tenant shall be responsible, but shall have no further rights with respect thereto. EXHIBIT Aliability, for permanently filling and closing the area known as the pit; subject to the indemnification provisions in Section 17 below.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the Lease or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011Cost of Improvement shall be paid or reimbursed by Landlord up to a maximum amount equal to $6,365,816.00 (i.e., $164.00 per rentable square foot of the Premises) (the “Tenant Improvement Allowance”), which amount is being made available by Landlord to be applied towards the Cost of Improvement, less any reduction in or charge against such amount pursuant to any applicable provisions of the Lease or of this Tenant Work Letter. Tenant shall be responsible, at its sole cost and expense, for payment of the entire Cost of Improvement in excess of the Tenant Improvement Allowance (and the Additional Tenant Improvement Allowance as provided below), including (but not limited to) any costs or cost increases incurred as a result of Tenant Delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “entire Tenant Improvement Allowance”Allowance toward the Cost of Improvements (subject to any applicable restrictions, as defined conditions, limitations, reductions or charges set forth in Section 2 of the Lease or in this Amendment, for the costs relating Tenant Work Letter) prior to the design and construction being required to expend any of Tenant’s improvements or which are otherwise “own funds for the Tenant Improvements. The funding of the Tenant Improvement Allowance items,” shall be made on a monthly basis or at other convenient intervals mutually approved by Landlord and Tenant and in all other respects shall be based on such commercially reasonable disbursement conditions and procedures as that term is defined Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, (i) under no circumstances shall the Tenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for any Cost of Improvement (or any other cost or expense) associated with any moveable furniture or trade fixtures, personal property or any other item or element which, under the applicable provisions of the Lease, will not become Landlord’s property and remain with the Building upon expiration or termination of the Lease, and (ii) except as otherwise expressly provided in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise expressly approved by Landlord in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Leasewriting, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is which has not disbursed been claimed or allocated for disbursement drawn by Tenant prior to December 31, 20132019 (as extended by force majeure or delays caused by Landlord), shall revert expire and shall no longer be available to Tenant thereafter. Notwithstanding anything to the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for and the Tenant Improvement Allowance shall have no further rights not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials in the Premises, if any, but with respect theretoto removal and remediation of any such Hazardous Materials, only to the extent such removal or remediation is required by Applicable Laws enforced as of the date of this Lease for improvements in the Premises generally (as opposed to the specific Tenant Improvements) and to the extent the same required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary occupancy density; and (b) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed). EXHIBIT A00 Xxxxxxxxx Xxxxxxx Xxxxxxx Xxxxxxxx Xxxx [Britannia Gateway Business Park] [Senti Biosciences, Inc.]

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the amount of up to, as defined in Section 2 of this Amendmentbut not exceeding $442,400.00, for the costs relating to the design and construction of Tenant’s the improvements or made pursuant to this Tenant Work Letter which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to or placed within the Premises (collectively, the “Tenant Improvements”); provided, however, that Landlord shall have no obligation to disburse all or any portion of the Tenant Improvement Allowance to Tenant unless Tenant makes a request for disbursement pursuant to the terms and conditions of Section 2.2 below prior to that date which the earlier of (a) the date is six (6) months after the completion of construction and (b) the date which is twelve (12) months after the Commencement Date. In no event shall Landlord be obligated to make disbursements to or on behalf of Tenant pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that which is not used to pay for the Tenant Improvement Allowance Items (as such term is defined below). Notwithstanding anything to the contrary this Tenant Work Letter, the portion of the Tenant Improvement Allowance disbursed for the Tenant Improvement Allowance Items described in Sections 2.2.1.1 and 2.2.1.8 shall not exceed in the aggregate $5.00 per rentable square foot of the Premises (i.e., up to $196,860.00 based on 39,372 rentable square feet in the Premises). In no event shall the Tenant Improvement Allowance be used for purposes of constructing improvements in the Premises for purposes of offering space for sublease or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Athe benefit of a subtenant.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Except for the Tenant Improvement Allowance Tenant shall be entitled responsible, as to use both cost and performance, for the Tenant Improvements. Landlord shall pay up to $45.00 per square foot of the Floor Area of the Demised Premises (“Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, ) for the costs relating to of the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvements. The Tenant Improvement Allowance items,” as that term is defined may be applied to all hard and soft construction costs, including architectural and engineering fees, moving costs, signage costs, data/telecommunications cabling costs, furniture, fixture and equipments costs, and construction management fees and for these purposes all of such costs shall be included in Section 2.2.1, below (collectively, each reference to costs of the “Tenant Improvements”)” or to similar phrases. In no the event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction that the costs of the Tenant Improvements or any are less than the Tenant Improvement Allowance ItemsAllowance, the cost savings shall belong to Landlord and Tenant shall not be entitled to any payment, refund, credit or reduction in Basic Rent or other charges due under the Lease. If the costs of the Tenant Improvements exceed the Tenant Improvement Allowance, Tenant shall have the right to require Landlord to pay up to an additional $6.00 per square foot of the Floor Area of the Demised Premises for the costs of the Tenant Improvements, as defined below, in a total amount which exceeds the sum of an addition to the Tenant Improvement Allowance. All Tenant Improvements for which Such additional contribution by Landlord to the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under reimbursed by Tenant by increasing the terms Basic Rent by a monthly amount determined by amortizing such additional amount at an interest rate of eight percent (8%) per annum over the Lease; provided, howeverLease Term. In such event, Landlord may, by written and Tenant shall enter into an amendment to the Lease memorializing the increase in the Tenant Improvement Allowance and the Basic Rent. Tenant agrees to provide notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination Landlord upon execution of this Lease, at Tenant’s expense, if Tenant desires to remove any Tenant Improvements and exercise its right to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aadditional contribution.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a tenant improvement allowance (the “Tenant Improvement Allowance”, as defined ) in Section 2 the total amount of this Amendment, Four Million Eight Hundred Twenty Thousand Seven Hundred Sixty and No/100 Dollars ($4,820,760.00) (calculated based upon Forty-Two and No/100 Dollars ($42.00) per rentable square foot of the Premises) for the costs relating to the initial design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “Tenant Improvements”). Notwithstanding anything to the contrary herein, the Tenant Improvement allowance may be used by Tenant in conjunction with the initial design and construction of the Tenant Improvements relating to both the Initial Premises and the Additional Premises. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which are paid for, in whole or in part, with the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice . With respect to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that which is not disbursed or allocated for disbursement by December 31Landlord in connection with the construction of the Initial Premises, 2013Landlord agrees and acknowledges that (i) any such amount shall be disbursed relating to the construction of the Additional Premises, shall revert and (ii) that the Additional Premises Commencement Date is not anticipated to occur until approximately the second (2nd) anniversary of the Commencement Date of this Lease. In addition, Landlord hereby acknowledges and agrees that Landlord’s failure to disburse the Tenant shall have no further rights Improvement Allowance with respect thereto. EXHIBIT Ato the Additional Premises pursuant to the TCCs of this Tenant Work Letter shall (following the applicable notice and cure periods set forth therein) constitute a Landlord default pursuant to the TCCs of Section 19.6 of the Lease, subject to, among other things, the Tenant’s offset rights contained therein; provided, however, Tenant’s application of such offset shall not be pre-conditioned upon receipt of an award from a court or arbitrator otherwise required pursuant to such Section 19.6.

Tenant Improvement Allowance. Commencing as Sublandlord shall provide to Subtenant a tenant improvement allowance of January 1, 2011, Tenant an amount not to exceed $20.00 per rentable square foot of the Premises ($1,642,880.00) (“Allowance”) to be used for the construction of leasehold improvements (“Initial Subtenant Improvements”) in accordance with a mutually agreeable space plan. The plans and specifications for the Initial Subtenant Improvements must be approved by Master Landlord and Sublandlord prior to commencement of construction thereof. The plans and specifications for the Initial Subtenant Improvements shall be entitled delivered to use Sublandlord and Master Landlord by May 15, 2003. The construction of Initial Subtenant Improvements shall be in compliance with this Sublease and the “Tenant Improvement Allowance”provisions of the Master Lease incorporated by reference. The Allowance shall be paid by Sublandlord to Subtenant or in its discretion, as defined in Section 2 of this Amendment, for the costs relating directly to the design and construction of Tenant’s improvements contractor or which are otherwise “Tenant subcontractors performing the Initial Subtenant Improvement Allowance items,” as that term is defined work, in Section 2.2.1, below (collectivelyinstallments, the “first at completion of 50% of the Initial Subtenant Improvements as certified by Subtenant’s architect and thereafter Sublandlord shall make payments as the Initial Subtenant Improvement Work progresses, but no more than once monthly upon receipt of an invoice and of Subtenant’s architect’s certificate indicating that the work related to such invoice is complete. Sublandlord shall pay the tenant improvement allowance to Subtenant or, in Sublandlord’s discretion, directly to the contractor and subcontractor(s) performing the Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction If, following completion of the Tenant Initial Subtenant Improvements or in accordance with the space plan, any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises Allowance remains, the Subtenant may apply the excess, not to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination exceed 50% or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion $821,440.00 of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Aallowance toward Rent due under this Sublease.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a tenant improvement allowance for the Expansion Premises in an amount equal to $490,880.00 (the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment), for the costs relating to the initial design and construction of Tenant’s improvements 's improvements, which are permanently affixed to the Expansion Premises only or which are otherwise “"Tenant Improvement Allowance itemsItems,” " as that term is defined in Section 2.2.1, below (collectively, the “"Tenant Improvements”"). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s 's construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance and, if applicable, the “Additional Improvement Allowance” (as defined in Section 2.5 below. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s 's approval of the “"Final Working Drawings”", as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly given following any earlier termination of this the Lease, at Tenant’s 's expense, to remove any Tenant Improvements which are “Specialty Improvements” (defined below) and to repair any damage to the Expansion Premises and Expansion Building caused by such removal and return the affected portion of the Expansion Premises to a Building standard general office condition; provided. In connection with the foregoing, however, Landlord hereby agrees that Landlord Tenant shall not require Tenant be obligated to remove upon termination any alterations or expiration of this Leasetenant improvements presently installed in the Expansion Premises. As used herein, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, “Specialty Improvements” shall mean any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary other than normal and customary general office, laboratory and/or Larc uses life science and research and development improvements, and shall expressly include (a) raised floor systems; (b) any showers or similar facilities in biotech facilitiesthe Premises that are not part of the base, shell and core of the Building or which require floor reinforcement or floor penetrations; (c) any staircase; and (d) any installations outside of the Premises, or any areas requiring floor reinforcement, personal baths and showers; and (e) any alterations or Tenant Improvements that adversely affect the Building structure or adversely affect the Building systems. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013the date (the “Allowance Outside Date”) which is twelve (12) months from the Expansion Possession Date, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT AB

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “"Tenant Improvement Allowance”") in the amount of up to, as defined in Section 2 of this Amendmentbut not exceeding, Nine Hundred Eighty-Nine Thousand Eight Hundred Thirty Dollars ($989,830.00) to help Tenant pay for the costs relating to of the design design, permitting and construction of Tenant’s 's initial improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Existing Premises and the Expansion Space (collectively, the “"Tenant Improvements”"); provided, however, that Landlord shall have no obligation to disburse all or any portion of the Tenant Improvement Allowance (nor the Additional Allowance, if applicable) to Tenant unless Tenant makes a request for disbursement pursuant to the terms and conditions of Section 2.2 below prior to that date which is one hundred eighty (180) days after the Suite 500 Expansion Commencement Date. Notwithstanding anything in this Tenant Work Letter to the contrary, an amount not to exceed Two Hundred Fifty-Nine Thousand Three Hundred Thirty Dollars ($259,330.00) of any unused amount of the Tenant Improvement Allowance shall be made available to Tenant to help Tenant pay for the actual and documented costs incurred by Tenant for the purchase of and installation of furniture, fixtures and equipment for the Expansion Space (the "FF&E Costs"). Landlord shall disburse from the Tenant Improvement Allowance the available portion thereof to help Tenant pay for the FF&E Costs actually incurred by Tenant within thirty (30) days after Landlord has received Tenant's written request for disbursement together with copies of paid invoices from third parties evidencing the amount of such FF&E Costs to be paid by Landlord; such disbursement request shall be delivered (if at all) no later than sixty (60) days after the Suite 500 Expansion Commencement Date. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum Tenant Improvement Allowance (nor the Additional Allowance ./ -/// -1- (if applicable)). In the event that there exists an "Over-Allowance Amount" under Section 4.3.1 of Tenant Work Letter of the Original Lease after application of the Tenant Improvement Allowance. All Allowance and Additional Allowance elected by Tenant Improvements to be applied for which improvements under the Original Lease, then Tenant shall have the right to have Landlord apply the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property and Additional Allowance hereunder for any such Over-Allowance Amount under the terms of the Original Lease; provided, however, Landlord may, by written notice to that Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require have the right to apply the Tenant Improvement Allowance nor the Additional Allowance described herein for costs which the Additional Allowance described in the Original Lease is to remove upon termination or expiration of this Leasebe used (i.e., or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any the Tenant Improvements constructed pursuant to Improvement Allowance and Additional Allowance under this Tenant Work Letter may only be applied to cover costs (includingi.e., without limitation, Larc improvementsthe Over-Allowance Amount) which constitute standard, non-extraordinary improvements under the Original Lease existing after application of the allowances under the Original Lease and may not be applied against the allowances under the Original Lease). Tenant shall not be entitled to receive any cash payment or credit against Rent or otherwise for ordinary office, laboratory and/or Larc uses in biotech facilities. Any any unused portion of the Tenant Improvement Allowance (nor the Additional Allowance, if applicable) which is not used to pay for the Tenant Improvement Allowance Items (as defined below). Notwithstanding anything above to the contrary, in the event there exists an Over-Allowance Amount (as defined in Section 4.2.1 below), Tenant shall have the option, exercisable upon written notice to Landlord, to require Landlord to provide a one-time additional improvement allowance (the "Additional Allowance") in the amount not to exceed One Million Four Hundred Eighty-Four Thousand Seven Hundred Forty-Five Dollars ($1,484,745.00). In the event Tenant exercises such option and as consideration for Landlord providing such Additional Allowance to Tenant, the Base Rent payable by Tenant throughout the entire Term of Tenant's lease of the Suite 500 Expansion Space ("Amortization Period") shall be increased by an amount sufficient to fully amortize such Additional Allowance throughout said period based upon equal monthly payments of principal and interest, with interest imputed on the outstanding principal balance at the rate of nine percent (9%) per annum (the "Amortization Rent"), subject to the following provisions regarding Tenant's right to pay off the Additional Allowance early. By way of illustration, if Tenant utilizes the entire Additional Allowance and if the Suite 500 Expansion Commencement Date occurs on January 1, 2018 (for a one hundred twenty-one (121) month term) then the initial Base Rent payable by Tenant for the Suite 500 Expansion Space under this Second Amendment shall be increased by $0.57 per rentable square feet (with an initial start rate of $5.37 per rentable square foot and the Base Rent schedule set forth in Section 4.2 of this Second Amendment shall be revised to reflect such increased Base Rent for all time periods under this Lease. Such revised Base Rent schedule shall be memorialized in an amendment to this Lease to be executed by Landlord and Tenant. The Tenant Improvement Allowance and the Additional Allowance may collectively be referred to herein as the "Allowances". Notwithstanding anything above to the contrary, Tenant shall have the right, to be exercised by written notice to Landlord at any time prior to March 31, 2020, to pay to Landlord the entirety of the Additional Allowance utilized by Tenant. In the event that Tenant makes such election, then Landlord shall provide Tenant with a calculation of the Additional Allowance amount that is owed (less any reduction of the same based on the Amortization Rent component of Base Rent previously paid by Tenant (if any) ("Landlord's Cost Calculation"). Tenant shall pay the amount set forth in Landlord's Cost Calculation (provided it is not disbursed or allocated for disbursement by December 31, 2013, shall revert to in error) within ten (10) days after Tenant's receipt thereof and Landlord and Tenant shall have promptly execute an amendment which will reflect such payment of the Additional Allowance, shall include a revised Base Rent schedule to reflect that Tenant is no further rights with respect theretolonger obligated to pay Amortization Rent, and shall confirm that no interest shall accrue on the Additional Allowance after the date of payment. EXHIBIT A./ -/// -2-

Tenant Improvement Allowance. Commencing as Landlord agrees to provide to Tenant an allowance with respect to the Premises of January 1, 2011, Tenant shall be entitled up to use a total of [redacted] (the “Tenant Improvement Allowance”), as defined in Section 2 based on [redacted] per rentable square foot of this Amendment, for the costs relating to Premises. Tenant agrees that at least [redacted] of the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1may be applied toward the cost of all (i) design (e.g., below architectural and engineering fees) and construction (including the cost of any permitted signage) (collectively, the “Tenant ImprovementsConstruction Costs”). In ) and (ii) all construction management fees; and that no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum more than [redacted] of the Tenant Improvement Allowance. All Tenant Improvements for which Allowance may be applied toward (i) the Tenant Improvement Allowance has been made available shall be deemed Landlordcost to purchase and install furniture, fixtures and equipment, including Tenant’s property under security system, (ii) the terms of the Lease; providedcost to AFDOCS//21459967 purchase and install Tenant’s telecommunication cabling and equipment, however(iii) so-called “soft costs” (including permitting fees), Landlord may, by and (iv) upon written notice to Tenant given concurrently with Landlord’s approval of , the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to next coming Base Rent due under the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed used by Tenant in accordance with the terms of this Work Letter within [redacted] after the Effective Date of the Lease shall be deemed forfeited by Tenant. All of the Tenant Work paid for by Landlord shall be the property of Landlord and shall be depreciated by Landlord. Tenant, with Landlord’s approval, not to be unreasonably withheld, conditioned or allocated for disbursement by December 31, 2013delayed, shall revert engage a qualified general contractor to Landlord perform Tenant’s leasehold improvements pursuant to a separate written agreement between Tenant and the general contractor, and Tenant shall promptly provide Landlord with a copy of such agreement. Such general contractor will perform the construction of the Premises on behalf of Tenant. Tenant shall cause its general contractor to meet with the Landlord’s agent as Landlord reasonably deems necessary to inform the various parties of the design, to assure compliance with the terms of the Lease, to coordinate construction of the Premises, to participate in walk-throughs, punch lists, etc. or for any other reason reasonably deemed necessary by Landlord. Landlord will further have the right to enter the Premises during construction thereof at any time and from time to time to inspect the Tenant Work for compliance with the provisions hereof and the Tenant Construction Documents. Landlord will charge a [redacted] supervisory fee for construction administration/coordination (based on the hard construction costs payable to Tenant’s general contractor), which shall be paid out of the Tenant Improvement Allowance. If Landlord engages a third party architect, engineer, or similar consultant to review Tenant’s Tenant Construction Documents (as defined in Section VI hereof) (e.g., the Tenant Work affects base Building structure and/or systems, etc.), any cost incurred by Landlord shall be considered included in the supervisory fee and Tenant will not be responsible for these costs. Landlord shall have no further rights obligation to manage the construction process and shall have no responsibility for any delays or cost overruns. With the exception of the [redacted] supervisory fee, there shall be no other fee or charge to Landlord in connection with respect thereto. EXHIBIT Athe Tenant Work, including any fee or charge for utilities or for the use of the loading dock or freight elevator during construction or in connection with Tenant’s move into the Building.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time improvement allowance (the “"Tenant Improvement Allowance”") in the amount of $100 per RSF of the Premises (i.e., as defined in Section 2 $15,931,000.00 for the 159,310 RSF of this Amendment, the Premises) for the costs relating to the initial design and construction of Tenant’s improvements or the improvements, which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “"Tenant Improvements”"). In addition, Landlord will provide a one-time allowance (the "Base Building Allowance") in the amount of $10 per RSF of the Premises (i.e., $1,593,100 for the 159,310 RSF of the Premises) to be used for modifications and upgrades to the Base Building systems and equipment serving the Building and Premises (the "Base Building Upgrades"). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum Tenant Improvement Allowance and Base Building Allowance. Tenant and Landlord shall mutually agree on the scope of the Base Building Upgrades, which shall be included in the Construction Documents and constructed by Tenant as a part of the Tenant Improvement Allowance. All If any portion of the Base Building Allowance remains after Tenant's construction of the Base Building Upgrades, such remaining portion may be used by Tenant Improvements for which other "Tenant Improvement Allowance Items", as defined below. The Base Building Allowance shall be disbursed for Base Building Upgrades in the same manner as the Tenant Improvement Allowance, in accordance with the terms of Section 2.2.1, below. Landlord shall disburse the Tenant Improvement Allowance has been made available and Base Building Allowance (other than the Final Retention) prior to any contribution to the cost of Tenant Improvements or Base Building Upgrades by Tenant (if any is required). Notwithstanding the foregoing or any contrary provision of this Lease, all Tenant Improvements shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance remaining as of the date that is not disbursed or allocated for disbursement by December 31, 2013, twelve (12) months after the Lease Commencement Date shall revert to remain with Landlord and Tenant shall have no further rights with respect right thereto. EXHIBIT AIn addition to the Tenant Improvement Allowance and Base Building Allowance, Landlord will pay Tenant's "Architect", as defined below, up to $0.15 per RSF of the Premises (i.e., up to $23,896.50) for the preparation of a preliminary space plan for the Premises.

Tenant Improvement Allowance. Commencing as Subject to the provisions of January 1this section 8, 2011, the Landlord shall pay to the Tenant shall be entitled to use an allowance (the “Additional Premises Tenant Improvement Allowance”) calculated on an amortized basis of $23.39 per square foot of the Additional Premises Area being an amount equal to $539,583.91. It is expressly understood and agreed that the Additional Premises Tenant Improvement Allowance is to be paid for the purpose of reimbursing the Tenant for a portion of its out of pocket expenses in completing the Tenant’s Work in the Additional Premises, as defined and fully equipping the Additional Premises with all trade equipment, lighting fixtures, furniture and operating equipment, installing appropriate signage and moving into the Additional Premises. Provided the Tenant is not then in Section 2 material breach of this AmendmentAgreement, for the costs Additional Premises Tenant Improvement Allowance shall be paid by the Landlord on a monthly draw basis to the Tenant upon receipt by the Landlord of a statutory declaration stating that there are no claims of builders’ lien or other liens or encumbrances affecting the Additional Premises with respect to work, services, materials and equipment relating to the design Additional Premises, and construction of that the Tenant’s improvements designers, contractors, subcontractors, works, and suppliers of materials and equipment have been paid in full for all work and services performed and materials and equipment supplied by them on or which are otherwise “to the Additional Premises. Notwithstanding the foregoing, the Landlord shall not be obligated to pay the Additional Premises Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of until the Tenant Improvements or any has executed and delivered a copy of this Agreement. The Landlord shall be permitted to set off and deduct from the Additional Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of any outstanding amounts owing by the Tenant Improvement Allowance. All Tenant Improvements for which to the Landlord pursuant to the Lease or this Agreement, provided that the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written is first given forty eight (48) hours notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Ato such outstanding amounts in order to remedy such breach.

Tenant Improvement Allowance. Commencing as Landlord’s architect shall design the Former MLS Space and the Building Lobby to Tenant’s specifications and then price out the proposed tenant improvements. Landlord will communicate to Tenant the total estimated cost of January 1the proposed tenant improvements, 2011, including design cost. Landlord will provide Tenant shall be entitled to use a tenant improvement allowance of Seven Hundred Twenty Thousand Dollars ($720,000.00) (the “Tenant Improvement TI Allowance”) for use until December 31, as defined in Section 2 2019. Tenant acknowledges and agrees that Twenty- one Thousand Eight Hundred Dollars ($21,800.00) of such TI Allowance has already been expended by Landlord for certain work performed on the second floor of the Building (including design costs) at Tenant’s request prior to the commencement of the term of this AmendmentLease, for and that the costs relating to remaining balance of the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement TI Allowance items,” as that term is defined in Section 2.2.1, below Six Hundred Ninety-eight Thousand Two Hundred Dollars (collectively, $698,200.00) (the “Tenant ImprovementsRemainder of the TI Allowance”). In the event the total estimated cost of the proposed improvements exceeds the Remainder of the TI Allowance, Tenant shall either modify its specifications to reduce the estimated cost of the proposed improvements or inform Landlord, in writing, of Tenant’s desire to have the tenant improvements constructed in accordance with Tenant’s original specifications. In the latter event Tenant shall deposit with Landlord the amount by which the estimated cost of the tenant improvements exceeds the Remainder of the TI Allowance and any additional amount previously paid by Tenant (the “Additional Amount”). Landlord shall engage Landlord’s general contractor to complete the construction of the improvements in accordance with the Work Letter attached hereto as Exhibit “D” and made a part hereof. Landlord shall be paid a construction management fee of three percent (3%) of the total cost of the tenant improvement work out of the Remainder of the TI Allowance. Tenant shall be responsible for any costs incurred by Landlord for such improvements (including the construction management fee) in excess of the sum of the Remainder of the TI Allowance and any Additional Amount previously paid by Tenant. Tenant shall be permitted to use up to Seventy-five Thousand Dollars ($75,000.00) of the Remainder of the TI Allowance for Tenant’s fixtures, furniture and equipment (“FF&E”). Promptly following completion of the tenant improvements in accordance with the Work Letter, and upon delivery to Tenant of reasonable written evidence of the total actual costs incurred by Landlord to complete the tenant improvements, Tenant shall reimburse Landlord for its actual costs incurred in excess of the sum of the Remainder of the TI Allowance and any Additional Amount advanced by Tenant as required above. If Tenant elects to use a portion of the Remainder of the TI Allowance to acquire up to Seventy-five Thousand Dollars ($75,000.00) of FF&E, Tenant shall deliver to Landlord reasonable written evidence of the total actual costs incurred by Tenant for such FF&E, and Landlord shall reimburse Tenant for such FF&E costs, up to a maximum of Seventy-five Thousand Dollars ($75,000.00), provided in no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with pay more than Six Hundred Ninety-eight Thousand Two Hundred Dollars ($698,200.00) for the tenant improvements and Tenant’s FF&E. If Landlord completes the construction of the tenant improvements and reimburses Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in for up to Seventy-five Thousand Dollars ($75,000.00) of FF&E at a total amount which exceeds cost less than the sum Remainder of the TI Allowance, Landlord shall have no liability to Tenant Improvement for any remaining portion of the TI Allowance. All Further, Landlord shall have no liability to Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms any portion of the Lease; provided, however, Landlord may, TI Allowance not utilized by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage for tenant improvements to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; providedor FF&E, howeveras provided hereinabove, that Landlord shall not require Tenant to remove upon termination on or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by before December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A2019.

Tenant Improvement Allowance. Commencing Tenant shall be entitled to receive the Tenant Improvement Allowance specified in Article I hereof to reimburse Tenant for the costs and expenses incurred in connection with the construction of Tenant's Work other than so-called "Excluded Costs" defined below. The Tenant Improvement Allowance shall be paid in two installments, the first of which shall be paid at such time as at least fifty percent (50%) of January 1Tenant's Work has been substantially completed. Such portion of Tenant's Work shall be deemed substantially completed when Tenant submits to Landlord (y) a letter from Tenant's Architect stating that at least fifty percent (50%) of Tenant's Work has been completed in substantial compliance with the Tenant's Plans, 2011and (z) reasonably detailed invoices (including all invoices and requisitions of all contractors and subcontractors) or other reasonably satisfactory evidence of costs incurred by Tenant in performance of the Tenant's Work (other than Excluded Costs) together with lien releases in form and substance reasonably satisfactory to Landlord from all suppliers of labor, materials or other services for the portion of Tenant's Work performed to date. Upon substantial completion of all of Tenant's Work, Tenant shall submit to Landlord the following documentation in order to be eligible to receive the final installment of the Tenant Improvement Allowance (the "Final TIA Installment"): (i) a final permanent certificate of occupancy for the Premises, (ii) invoices (including all invoices and requisitions of all contractors and subcontractors) or other reasonably satisfactory evidence of costs incurred by Tenant in performance of the Tenant's Work (other than the Excluded Costs), (iii) lien releases in form and substance reasonably satisfactory to the Landlord from all suppliers of labor, materials or other services, (iv) a final Certificate of Substantial Completion from Tenant's Architect certifying to the completion of the Tenant's Work in substantial compliance with the Tenant's Plans, and (v) a complete set of Record Drawings, as defined in the Work Letter, for Tenant's Work. Landlord shall have no obligation to pay any portion of the Tenant Improvement Allowance if the Lease is terminated as a result of a Default hereunder. Each installment of the Tenant Improvement Allowance shall be paid to Tenant within thirty (30) days after receipt of all of the documentation required herein. Notwithstanding the foregoing, if Tenant fails to obtain a temporary or final certificate of occupancy permitting Tenant to legally occupy the Premises as a result of a defect in Landlord's Work, but satisfies the remainder of the foregoing requirements, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of receive the Tenant Improvement Allowance, and Tenant shall promptly obtain such certificate of occupancy after Landlord cures such defect in accordance with Section 8.1 hereof. All In addition, as to that portion of such delays occurring after the Outside Completion Date, each day of delay between the date that Tenant Improvements is denied such certificate of occupancy as a result of a defect in Landlord's Work and the date that Tenant obtains a certificate of occupancy after Landlord cures such defect shall be deemed a Landlord Delay for which the purposes of determining the Rent Commencement Date. If Landlord fails to timely pay the Tenant Improvement Allowance in the manner set forth herein, Tenant shall give Landlord (and the holder of any existing or future mortgage, deed of trust, xxxxxxxxx, or similar instrument covering the Premises (each a "Mortgagee") of which Tenant has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by received written notice) written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”such failure, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that if Landlord shall has not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of paid the Tenant Improvement Allowance that is not disbursed or allocated in accordance with this Section 3.6 within thirty (30) days after receipt of such notice from Tenant and following the giving of a second written notice by Tenant and Landlord's failure to cure within five (5) days thereafter, interest shall accrue on such unpaid amount at the rate of the "Prime Rate" plus four (4%) (the "Default Rate"), and, if there remains any amounts unpaid by Landlord to Tenant hereunder after interest has commenced to accrue for disbursement by December 31, 2013, shall revert at least thirty (30) days and after Tenant gives a third written notice to Landlord and its Mortgagee of whom Tenant has been provided notice and Landlord fails to cure within a period of five (5) days thereafter, then Tenant shall be entitled to offset the unreimbursed costs, together with interest as aforesaid, against fifteen percent (15%) of the monthly Base Rent due hereunder until the Tenant Improvement Allowance and all accrued interest thereon shall have no further rights with respect theretobeen reimbursed in full. EXHIBIT AFor purposes hereof, the "Prime Rate" shall mean the rate equal to the prime commercial rate from time to time established by the Fleet National Bank, or its successor.

Tenant Improvement Allowance. Commencing as Landlord shall contribute to the cost of January 1, 2011, the Tenant shall be entitled to use Improvements a one-time tenant improvement allowance (the “"Tenant Improvement Allowance”") in the amount of up to, as defined but not exceeding Five Million Six Hundred Fifty-Four Thousand One Hundred Sixty Dollars ($5,654,160.00 (i.e., One Hundred Twenty Dollars ($120.00) per rentable square foot of the Premises based on 47,118 rentable square feet in Section 2 of this Amendmentthe Premises), to help pay for the costs relating to of the design design, permitting and construction of Tenant’s 's improvements or which are otherwise “Tenant Improvement Allowance items,” permanently affixed to the Premises and depicted in the approved Final Working Drawings, as that such term is defined in Section 2.2.1, below (collectively, the “"Tenant Improvements”"). Except as otherwise expressly agreed to by Tenant, in no event shall costs incurred by Landlord prior to the date hereof for the design of the Tenant Improvements be deducted from the Tenant Improvement Allowance. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available and in no event shall Landlord be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice obligated to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following disburse any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, Allowances (as defined below) beyond that Landlord date which is eighteen (18) months after the Lease Commencement Date (the "TIA Cutoff Date"). Tenant shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance or the Additional Allowance which is not used to pay for the Tenant Improvement Allowance Items (as defined below). Notwithstanding anything above to the contrary, in the event there exists an Over-Allowance Amount (as defined in Section 4.3.1 below), Tenant shall have the option, exercisable upon written notice to Landlord prior to the date Tenant is obligated to pay such Over-Allowance Amount, to require Landlord to provide a one-time additional improvement allowance (the "Additional Allowance") in the amount not to exceed Twenty Dollars ($20.00) per rentable square foot of the Premises, (i.e., up to Nine Hundred Forty-Two Thousand Three Hundred Sixty Dollars ($942,360.00) based on 47,118 rentable square feet in the Premises). In the event Tenant exercises such option and as consideration for Landlord providing such Additional Allowance to Tenant, the Base Rent payable by Tenant throughout the entire one hundred twenty-six (126) month initial 843078.08/SD374622-00033/8-4-16/MLT/dek Exhibit X-0- XXXXXXX XXX - XXX XXXXX XXXXX[Xxxxxxxx, Inc.] Lease Term ("Amortization Period") shall be increased by an amount sufficient to fully amortize such Additional Allowance throughout said one hundred twenty-six (126) month period based upon equal monthly payments of principal and interest, with interest imputed on the outstanding principal balance at the rate of nine percent (9%) per annum (the "Amortization Rent"), subject to the following provisions regarding Tenant's right to pay off the Additional Allowance early. By way of illustration, if Tenant utilizes the entire Additional Allowance then the initial Base Rent payable by Tenant under this Lease shall be increased by $0.25 per rentable square feet (with an initial start rate of $5.05 per rentable square foot and the Base Rent schedule set forth in Section 8 of the Summary shall be revised to reflect such increased Base Rent for all time periods under this Lease. Such revised Base Rent schedule shall be memorialized in an amendment to this Lease to be executed by Landlord and Tenant. In the event the Lease shall terminate for any reason, including, without limitation, as a result of an Event of Default by Tenant under the terms of the Lease or this Tenant Work Letter, Tenant acknowledges and agrees that the unamortized balance of the Additional Allowance which has not been paid by Tenant to Landlord as of the termination date pursuant to the foregoing provisions of this Section 2.1, shall become immediately due and payable as unpaid rent which has been earned as of such termination date. In addition, in no event shall the Amortization Rent be abated for any reason whatsoever. The Tenant Improvement Allowance and the Additional Allowance may collectively be referred to herein as the "Allowances". Notwithstanding anything above to the contrary, Tenant shall have the right, to be exercised by written notice to Landlord at any time during the first thirty-six (36) months of the Lease Term, to pay to Landlord the entirety of the Additional Allowance utilized by Tenant. In the event that Tenant makes such election, then Landlord shall provide Tenant with a calculation of the Additional Allowance amount that is owed (less any reduction of the same based on the Amortization Rent component of Base Rent previously paid by Tenant (if any) ("Landlord's Cost Calculation"). Tenant shall pay the amount set forth in Landlord's Cost Calculation (provided it is not disbursed or allocated for disbursement by December 31, 2013, shall revert to in error) within ten (10) days after Tenant's receipt thereof and Landlord and Tenant shall have promptly execute an amendment which will reflect such payment of the Additional Allowance, shall include a revised Base Rent schedule to reflect that Tenant is no further rights with respect thereto. EXHIBIT Alonger obligated to pay Amortization Rent, and shall confirm that no interest shall accrue on the Additional Allowance after the date of payment.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the First Amendment or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011the cost of construction of the Tenant Improvements shall be paid or reimbursed by Landlord up to a maximum amount equal to $23,801,750.00 (the “Tenant Improvement Allowance”), which amount is being made available by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Substitute Premises. Tenant shall be responsible, at its sole cost and expense, for payment of the entire Cost of Improvements of the Tenant Improvements in excess of the Tenant Improvement Allowance (such excess amount is referred to herein as the “Tenant Funds Amount”), including (but not limited to) any costs or cost increases incurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “entire Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, toward the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction Cost of Improvements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or any Tenant Improvement Allowance Items, as defined below, charges set forth in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined First Amendment or in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvementsLetter) which constitute standard, non-extraordinary improvements prior to being required to expend any of Tenant’s own funds for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe Tenant Improvements. Any portion The funding of the Tenant Improvement Allowance that is not disbursed shall be made on a monthly basis or allocated for disbursement at other convenient intervals mutually approved by December 31, 2013, shall revert to Landlord and Tenant and in all other respects shall have be based on such commercially reasonable disbursement conditions and procedures as Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no further rights circumstances shall the Tenant Improvement Allowance or any EXHIBIT B -9- THE COVE AT OYSTER POINT [First Amendment] [Global Blood Therapeutics, Inc.] portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant or cabling expenses. Notwithstanding anything to the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for and the Tenant Improvement Allowance shall not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials in the Substitute Premises, if any, but with respect thereto. EXHIBIT Ato removal and remediation of any such Hazardous Materials, only to the extent such removal or remediation is required by Applicable Laws enforced as of the date of this First Amendment for improvements in the Substitute Premises generally (as opposed to the specific Tenant Improvements) and to the extent the same required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Substitute Premises for the Permitted Use assuming a normal and customary occupancy density; (b) costs to bring the Project into compliance with Applicable Laws to the extent required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Substitute Premises for the Permitted Use assuming a normal and customary office occupancy density; (c) construction costs in excess of the contract amount stated in the contract with the General Contractor, as approved by Tenant (not to be unreasonably withheld), except for increases set forth in change orders approved by Tenant; (d) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed); (e) attorneys’ fees incurred in connection with negotiation of construction contracts, and attorneys’ fees, experts’ fees and other costs in connection with disputes with third parties; (f) interest and other costs of financing construction costs; (g) costs incurred as a consequence construction defects or default by a contractor; (h) costs as a consequence of casualties; (i) penalties and late charges attributable to Landlord’s failure to pay construction costs; and (j) costs due to compliance with the soil management plan for the Project or its appendices.

Tenant Improvement Allowance. Commencing Estimates. Sublandlord and Subtenant agree that Sublandlord shall bear the cost and expense of the construction and installation of the tenant improvements to be constructed by Subtenant within the Premises in accordance with Section 8 of the Consent, as of January 1more particularly described on the attached Exhibit D (the "Tenant Improvements"), 2011, Tenant shall be entitled up to use One Million Two Hundred Thousand Dollars ($1,200,000) (the “"Tenant Improvement Allowance”, as defined ") and that Subtenant shall bear all costs and expenses in Section 2 excess of this Amendment, for such amount. Prior to commencing the costs relating to the design construction and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction installation of the Tenant Improvements or any Tenant Improvement Allowance ItemsImprovements, as defined below, in a total amount which exceeds the sum Subtenant shall provide Sublandlord with an estimate of the Tenant Improvement Allowancecost to complete same as reasonably determined by Subleasee's contractor (the "Estimate"). All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms Upon receipt of the Lease; providedEstimate, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior Sublandlord shall promptly deposit an amount equal to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion lesser of the Tenant Improvement Allowance and the Estimate into a separate joint construction disbursement account to be held by a mutually agreeable financial institution (the "Construction Account"). Upon Sublandlord's receipt of either (a) a certificate of occupancy or recorded Notice of Completion of improvements for work relating to the 2nd and 3rd floors, referenced as item 5 of the attached Exhibit D and intended as "Phase One" of the Tenant Improvements, and (b) written documentation reasonably acceptable to Sublandlord showing that the construction cost of such Phase One exceeded the amount Sublandlord deposited in the Construction Account, Subtenant shall be entitled to withdraw all of the funds and accrued interest in the Construction Account. If the construction cost of Phase One is not disbursed less than the amount Sublandlord deposited in the Construction Account, this same process will be followed as succeeding phases of the Tenant Improvements are completed, until either Subtenant has withdrawn all of the funds Sublandlord deposited in the Construction Account or allocated for disbursement all of the Tenant Improvements are completed. Any balance of the funds Sublandlord deposited in the Construction Account remaining after all Tenant Improvements are completed will be promptly returned to Sublandlord. Sublandlord and Subtenant acknowledge that Subtenant expects to withdraw all funds held in the Construction Account by no later than December 31, 20132002. In addition to the Tenant Improvement Allowance outlined above, Sublandlord, at Sublandlord's sole cost and expense, shall revert be responsible for repainting the exterior of the Building within three (3) years of the Commencement Date, provided this Sublease is then in effect. Sublandlord shall coordinate with Subtenant regarding scheduling a time to Landlord complete the painting. Subtenant and Tenant Sublandlord shall have no further rights with respect thereto. EXHIBIT Amutually agree on the color and quality of the paint, both of which shall be subject to approval by Master Landlord.

Tenant Improvement Allowance. Commencing as of January 1In order for the Premises to be useful to Tenant and marketable in the future for Landlord, 2011Landlord and Tenant agree that Landlord shall pay an improvement allowance to Tenant in order for Tenant to construct a buildout at the Premises pursuant to the plans and specifications set forth in Exhibit B attached hereto. Thus, Landlord and Tenant acknowledge and agree that Tenant shall be entitled to use provided an Improvement Allowance in the “Tenant Improvement Allowance”, as defined in Section 2 amount of this Amendment, approximately One-Million and Six-Hundred and Fifty-Three Thousand Dollars ($1,680,000.00) for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined work described in Section 2.2.1, below accordance with Exhibit B (collectively, the “Tenant Improvements”). In no event No Material Deviations from Exhibit B shall Landlord be obligated to make disbursements pursuant to this made by Tenant Work Letter without Landlord’s prior written consent, which shall not be unreasonably withheld. “Material deviations” shall be defined as an increase or otherwise in connection with Tenant’s construction decrease of $100,000 or more at the Tenant Improvements or any Premises, it being agreed that the total Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion 1 Targeting Centre leased to Tenant under a separate lease shall not exceed $2,000,000. Approval of the Premises to a Building standard general office condition; provided, however, that plans and specifications by Landlord shall not require constitute the assumption of and responsibility by Landlord for their accuracy or sufficiency, and Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, shall be solely responsible for such items. Tenant shall be responsible for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) and all costs and expenses which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilitiesexceed the Improvement Allowance. Any portion of the Tenant total Improvement Allowance shall be paid to Tenant or to Tenant’s general contractor, Xxxxxx Xxxxx Company, within 30 days following receipt by Landlord of (1) invoices; (2) an AIA sworn statement from the general contractor, (3) an affidavit from the Tenant that the payments from the prior disbursement request have been made in full; (4) Landlord lender approval and submittal by Tenant of lender-requested mechanics or materialmen lien waivers or their functional equivalents under applicable Connecticut’s materialmen lien laws; and (5) and the certification of Tenant and its architect that the Tenant Improvements have been made in accordance with applicable laws, codes and ordinances. The Improvement Allowance shall be disbursed in the amount reflected on the invoices meeting the requirements above. Notwithstanding anything herein to the contrary, Landlord shall not be obligated to disburse any portion of Improvement Allowance during the continuance of an uncured default under the Lease, and Landlord’s obligation to disburse shall only resume when and if such default is not disbursed or allocated for disbursement cured. The final 7 1/2% of the Improvement Allowance shall be withheld by December 31, 2013, shall revert to Landlord and disbursed upon receipt of the final sworn statement. Immediately after the final payment is made, Tenant shall have no further rights provide Landlord with respect thereto. EXHIBIT Aconfirmation of full payment from all contractors, subcontractors, and vendors who performed work to the Premises desired by Tenant.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled Landlord has agreed to use contribute a one-time tenant improvement allowance (the “Tenant Improvement Allowance”, as defined ) in Section 2 the amount of up to $2,901,140.00 (based on a rate of $110.00/rentable square foot of the Premises) to reimburse Tenant for (a) the actual hard and soft costs (but subject to the last sentence of this AmendmentSection 3.02) of completing, for constructing or installing the costs Tenant’s Work to the Premises, (b) government permit fees relating to the design and construction of such Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1Work, below and (collectivelyc) Tenant’s actual costs for computer cabling, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise furniture, fixtures and equipment in connection with Tenant’s construction Work. The Tenant Improvement Allowance, or a portion thereof, will be disbursed by Landlord to Tenant no less frequently than monthly (the “Monthly Draws”) within twenty (20) days (such period, the “Disbursement Date”) after Tenant submits all of the following to Landlord: (i) a written certification from Tenant’s architect stating that the improvements (to the extent completed during the period covered by the Monthly Draw) were completed in accordance with the Landlord-approved plans and specifications therefor, (ii) partial lien releases from all contractors and materialmen providing services or supplies, through the date of the pertinent Monthly Draw, in connection with the improvements covered by such Monthly Draw, (iii) invoices or other reasonable evidence of the costs incurred in connection with the improvements covered by the Monthly Draw, through the date of the pertinent Monthly Draw, and (iv) a certificate of completion or certificate of occupancy (but, only with respect to the final Monthly Draw, or sooner, if the pertinent improvements are completed sooner than the month of the final Monthly Draw) for the Premises (if required by applicable Requirements and if necessary pursuant to such Requirements, Landlord shall reasonably cooperate, at no expense to Landlord, with respect thereto). If Tenant timely submits to Landlord each of the foregoing and Landlord fails to disburse the applicable portion of the Tenant Improvements or Improvement Allowance when due and payable hereunder, then Landlord shall pay interest on the undisbursed portion of any such due and unpaid portion of the Tenant Improvement Allowance Itemsat the Default Rate, as defined belowuntil paid by Landlord. If Landlord in good faith disputes any Monthly Draw request and/or asserts that the required supporting documentation for such Monthly Draw was not duly submitted, it shall pay any undisputed portion of the Monthly Draw and provide, in a total amount which exceeds writing, to Tenant the sum basis for not paying the balance within the above-referenced thirty (30) day timeframe for payment, with Tenant entitled to interest at the Default Rate hereunder only with respect to unpaid portions of the Tenant Improvement Allowance to the extent Landlord’s non-payment continues after same is due and payable hereunder. Tenant shall be solely responsible for any and all costs of designing and constructing improvements to the Premises in excess of the Tenant Improvement Allowance. All Tenant Improvements for shall have until the date which is the last day of the month in which the second (2nd) anniversary of the Commencement Date occurs to perform work in the Premises that is reimbursed by the Tenant Improvement Allowance. In the event that Xxxxxx does not use the entire Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms on or before second (2nd) anniversary of the Lease; providedCommencement Date, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that is not disbursed (up to twenty percent (20%), or allocated $580,228.00, of the Tenant Improvement ​ ​ Allowance) shall be applied as a credit against Fixed Rent next coming due and payable under this Lease. Notwithstanding anything contained herein to the contrary, up to $580,228.00 (or twenty percent (20%)) of the Tenant Improvement Allowance may be used to reimburse Tenant’s reasonable, out-of-pocket architectural and engineering costs incurred for disbursement by December 31Tenant’s Work, 2013pursuant to Monthly Draw requirements, shall revert to Landlord accompanied with Tenant’s relevant invoices and Tenant shall have no further rights with respect thereto. EXHIBIT Apaid receipts.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “"Initial Allowance") in the amount of up to, but not exceeding Forty-Five Dollars ($45.00) per rentable square foot of the Premises (i.e., up to One Million, Three Hundred Eighty-Five Thousand, Seven Hundred Seventy-Five and 00/100 Dollars ($1,385,775.00) based on 30,795 rentable square feet of the Premises), to help Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, pay for the costs relating to of the design design, permitting and construction of Tenant’s 's initial improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below permanently affixed to the Premises (collectively, the “"Tenant Improvements”"). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of Notwithstanding the Tenant Improvements or any Tenant Improvement foregoing, if there is an Over-Allowance Items, Amount (as defined below), then Tenant shall have the option, exercisable upon written notice to Landlord prior to the date Tenant is obligated to pay such Over-Allowance Amount to Landlord pursuant to Section 4.2.1 below, to receive an additional one-time tenant improvement allowance to help pay for such Over-Allowance Amount (the "Additional Allowance") in a total the amount which exceeds the sum of up to, but not exceeding $307,950.00 (i.e., $10.00 per rentable square foot of the Tenant Improvement AllowancePremises). All Tenant Improvements As consideration for which Landlord providing the Tenant Improvement Additional Allowance has been made available to Tenant, the amount of the Additional Allowance provided by Landlord shall be deemed amortized on a monthly basis over the scheduled seven (7) year initial Lease Term at an interest rate of ten percent (10%) per annum, and each such monthly payment of amortization and interest (collectively, the "Amortization Rent") shall be paid by Tenant to Landlord as an increase in the Base Rent, or at Landlord’s property 's option as Additional Rent, on or prior to the first (1st) day of each month throughout such seven (7) year initial Lease Term. If the Lease shall terminate for any reason, including without limitation as a result of a default by Tenant under the terms of the Lease; providedLease or this Tenant Work Letter, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval acknowledges and agrees that the unamortized balance of the “Final Working Drawings”, Additional Allowance which has not been paid by Tenant to Landlord as that term is defined in Section 3.3, below, require Tenant, prior of the termination date pursuant to the end foregoing provisions of this Section 2.1 shall become immediately due and payable as unpaid rent which has been earned as of such termination date, specifically including a termination pursuant to Article 19 of the Lease Term or promptly following Lease. In addition, in no event shall the Amortization Rent be abated for any earlier termination reason whatsoever, including without limitation, pursuant to Articles 11 and 12 of this the Lease, at Tenant’s expense, to remove any Tenant Improvements . The Initial Allowance and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises Additional Allowance so elected to a Building standard general office condition; provided, however, that Landlord shall not require be received by Tenant are sometimes collectively referred to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of herein as the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A"

Tenant Improvement Allowance. Commencing as Sublessor shall, at its sole cost, expense and discretion, pay all costs to construct any fire corridors on the ground floor of January 1Building 6 required for exiting Building 6. In addition, 2011, Tenant Sublessor shall be entitled provide Sublessee with a tenant improvement allowance of up to use and in no event greater than $25.00 per rentable square foot or $794,150.00 for the second floor space and $30.—per rentable square foot or $64,740.00 for the first floor space for a total of $858,190 (the “Tenant Improvement Allowance”) the final “Allowance” of which will be determined using the rentable square footage as described in paragraph B of the Recitals. In addition, as defined in Section 2 of this Amendment, Sublessor shall pay Sublessee a moving allowance equal to $1.00 per rentable square foot or $33,924.00 (“Moving Allowance”) expendable for the costs and expenses relating to the relocation of Sublessee’s business (including, but not limited to, costs of moving Sublessee’s fixtures, furniture, equipment and general moving related expenses) from its current space to the Premises. The Moving Allowance shall be paid by Sublessor to Sublessee upon Sublessor’s receipt of Sublessee’s written demand therefor, accompanied by, as applicable, invoices documenting and evidencing such moving related costs and expenses. The Allowance may be used for but not limited to the cost of preparing design and construction documents and mechanical and electrical plans for tenant improvements for the Sublet Premises and for both hard and soft costs in connection with such tenant improvements. The Allowance, less a 10% retainage (which retainage shall be payable as part of Tenant’s improvements the final draw), shall be paid to the order of the general contractor that performs, or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectivelyarchitect who designs, the “Tenant Improvements”)tenant improvements, in periodic disbursements within thirty (30) days after receipt of the following documentation: (i) an application for payment and sworn statement of contractor substantially in the form of AIA Document G-702 covering all work for which disbursement is to be made to a date specified therein; (ii) a certification from an AIA architect substantially in the form of the Architect’s Certificate for Payment which is located on AIA Document G702, Application and Certificate of Payment; (iii) Contractor’s, subcontractor’s and material supplier’s waivers of liens which shall cover all tenant improvements for which disbursement is being requested and all other statements and forms required for compliance with the mechanics’ lien laws of the state in which the Sublet Premises is located, together with all such invoices, contracts, or other supporting data as Sublessor may reasonably require; (iv) a cost breakdown for each trade or subcontractor performing the tenant improvements; (v) plans and specifications for the tenant improvements, together with a certificate from an AIA architect that such plans and specifications comply in all material respects with all laws affecting the Project or Sublet Premises; (vi) copies of all construction contracts for the tenant improvements, together with copies of all change orders, if any; and (vii) a request to disburse from Sublessee containing an approval by Sublessee of the work done and a good faith estimate of the cost to complete the tenant improvements. Upon completion of the tenant improvements, and prior to final disbursement of the Allowance, Sublessee shall furnish Sublessor with: (1) general contractor and architect’s completion affidavits, (2) full and final waivers of lien, (3) receipted bills covering all labor and materials expended and used, (4) as-built plans of the tenant improvements, and (5) the certification of Sublessee and its architect that the tenant improvements have been installed in a good and workmanlike manner in accordance with the approved plans, and in accordance with applicable laws, codes and ordinances. In no event shall Landlord Sublessor be required to disburse the Allowance more than one time per month. If the tenant improvements exceed the Allowance, Sublessee shall be entitled to the Allowance in accordance with the terms hereof, but each individual disbursement of the Allowance shall be disbursed in the proportion that the Allowance bears to the total cost for the tenant improvements, less the 10% retainage referenced above. Notwithstanding anything herein to the contrary, Sublessor shall not be obligated to make disbursements pursuant disburse any portion of the Allowance during the continuance of Sublessee’s uncured default under this Sublease, and Sublessor’s obligation to disburse shall only resume when and if such default is cured. In no event shall the Allowance be used for rent, operating expenses, relocation costs, the purchase of equipment, furniture or other items of personal property of Sublessee but rather must be used in accordance with the requirements as set forth in the Master Lease. If Sublessee does not submit a request for payment of the entire Allowance to Sublessor in accordance with the provisions contained in this Tenant Work Letter Section by November 1, 2010, any unused portion of the Allowance shall accrue to the sole benefit of Sublessor, it being understood that Sublessee shall not be entitled to any credit, abatement or otherwise other concession in connection therewith. Should Sublessor fail to pay over any portion of the Allowance or the Moving Allowance due to Sublessee within the time period set forth herein, then Sublessee may set off such unpaid amounts from its payment of Fixed Rent to Sublessor hereunder, provided that Sublessee has, prior to November 1, 2010, requested such unpaid amounts from Sublessor in accordance with this Section 21. Sublessee shall be responsible for all applicable state sales or use taxes, if any, payable in connection with Tenantthe tenant improvements and/or Allowance. Furthermore, Sublessee agrees to a full open book process allowing Sublessor or Sublessor’s representative to review construction costs records and schedule to confirm actual construction items and costs as outlined above. There will be no deduction from the Allowance for Sublessee’s construction of management fee other than any construction management fee imposed by Prime Lessor in accordance with the Tenant Improvements Prime Lease. Except for any such Prime Lessor construction management fee, Sublessee shall not be required to pay any construction management fees or any Tenant Improvement Allowance Itemsother similar fees for the tenant improvements. Notwithstanding the foregoing, as defined below, in a total amount which exceeds Sublessee hereby agrees and acknowledges that all tenant improvements to the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall Sublet Premises must be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, approved by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, Prime Lessor prior to being made as provided in the end of the Lease Term or promptly following any earlier termination of this Prime Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”), as defined in the amount set forth in Section 2 12 of this Amendmentthe Summary, for the costs relating to the initial design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1permanently affixed (including furniture, below equipment and equipment attached to the walls, ceiling or slab) to the Premises (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of Tenant Improvement Allowance. In the event that the Tenant Improvement AllowanceAllowance is not fully utilized by Tenant by the first (1st) anniversary of the Lease Commencement Date, then such unused amounts shall revert to Landlord, and Tenant shall have no further rights with respect thereto. Any Tenant Improvements that require the use of Building risers, FOUR EMBARCADERO CENTER 607152.05/WLA EXHIBIT B [Nighthawk Radiology Services, LLC] E2621-081/1-8-07/kt/kt -1- [AMLGMN] raceways, shafts and/or conduits, shall be subject to Landlord’s reasonable rules, regulations, and restrictions, including the requirement that any cabling vendor must be selected from a list provided by Landlord, and that the amount and location of any such cabling must be approved by Landlord. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly given following any earlier termination of this Lease, require Tenant, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office conditiontheir condition existing prior to the installment of such Tenant Improvements; provided, however, that Landlord shall not require Tenant to remove that, notwithstanding the foregoing, upon termination or expiration request by Xxxxxx at the time of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration request for Landlord’s approval of this Lease, any Tenant Improvements constructed pursuant to the “Final Working Drawings,” as that term is defined in Section 3.3 of this Tenant Work Letter (includingLetter, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of Landlord shall notify Tenant whether the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert Improvements will be required to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Abe removed pursuant to the terms of this Section 2.1.

Tenant Improvement Allowance. Commencing as Landlord agrees to make available to Tenant an allowance of January 1$25.00 per rentable square feet on 9,520 rentable square feet, 2011, Tenant shall be entitled such amount for being for improvements to use the Premises (“Tenant Improvement Allowance”, as defined in Section 2 ). Tenant shall bear the entire cost of this Amendment, for performing the costs relating improvements to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below Expansion Space (collectively, the “Tenant ImprovementsLeasehold Work”) (including, without limitation, design of the Leasehold Work and preparation of the working drawings, costs of construction labor and materials (the “Construction Hard Costs”). In no event shall , electrical usage during construction (allocated to Tenant as reasonably agreed by Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise and Tenant), janitorial services, signage, fees, and related non-ad valorem taxes and insurance costs, all of which costs are herein collectively called the “Total Construction Costs”) in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum excess of the Tenant Improvement Allowance. All Landlord or its designee shall coordinate the relationship between the Leasehold Work, the Building, and the Building Systems. In consideration for Landlord’s services, Tenant Improvements shall pay to Landlord a construction supervision fee (the “Construction Supervision Fee”) equal to three percent (3.00%) of the Total Construction Costs for all improvements and alterations made to the Premises other than the shell construction, which Construction Supervision Fee shall be paid from the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms Allowance. Tenant may utilize up to $5.00 per rentable square feet of the Lease; providedabove Tenant Improvement Allowance towards the purchase of workstations and furniture (“FF&E”), howeversignage, Landlord maydata and telephone cabling, by written notice to other soft costs, and relocation costs. Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to must use such allowance before the end of the Lease Term December 15, 2007 or promptly following any earlier termination of this Lease, at Tenant’s expense, Tenant shall have deemed to remove any Tenant Improvements and forfeit all rights to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated Allowance. Landlord shall perform the work for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT Athe improvements based on a mutually agreed upon scope of work.

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “Tenant Improvement Allowance”) in the amount of BRITANNIA POINTE GRAND BUSINESS PARK [Cytokinetics, as defined in Section 2 Inc.] $1,631,740.00 (i.e., $20.00 per rentable square foot of this Amendment, the Premises) for the costs relating to the initial design and construction of Tenant’s improvements which are permanently affixed to the Premises or which are otherwise “Tenant Improvement Allowance itemsItems,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”), which shall be available for disbursement under this Tenant Work Letter commencing on January 1, 2011. In Except with respect to the Landlord Work, in no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum Tenant Improvement Allowance. Tenant hereby acknowledges and agrees that any portion of the Tenant Improvement AllowanceAllowance as to which Tenant has not requested disbursement pursuant to the terms of this Tenant Work Letter as of December 31, 2013, shall revert to Landlord and Tenant shall have no further right thereto. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to not later than the end of the Lease Term Term, or promptly given following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require their condition existing prior to the installation of such removed Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT AImprovements.

Tenant Improvement Allowance. Commencing as of January 1, 2011, (a) Tenant shall be entitled pay for all Tenant Improvements, except that Landlord shall provide to use Tcnant an allowance (the “"Tenant Improvement Allowance”, as defined ") in Section 2 the amount of this Amendment, for Forty Five Dollars ($45.00) per rental square foot of the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Building. The Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “may be used by Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this for any costs incurred by Tenant Work Letter or otherwise in connection with Tenant’s the design, permitting, management (including fees paid to a third party construction manager) and construction of the Tenant Improvements or (including any installation costs of Tenant's fixtures and equipment, but not including the purchase price of such items). (b) Landlord shall pay to Tenant the Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds accordance with the sum following provisions: (i) fifty percent (50%) of the Tenant Improvement Allowance. All Allowance shall be paid at such time as fifty percent (50%) or more of the cost of the Tenant Improvements Improvements, as such costs are estimated or fixed in the agreement between Tenant and Tenant's Contractor, are due and payable in accordance with invoices delivered to Tenant, which invoices have been approved for payment in writing by Tenant's architect (a copy of which shall be delivered to Landlord), and (ii) fifty percent (50%) of the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms paid upon completion of the LeaseTenant Improvements and delivery to Landlord of an invoice together with appropriate lien release documentation evidencing the full payment by Tenant and Contractor of all costs of the Tenant Improvements. Landlord will pay the invoice within thirty (30) days after Landlord's receipt of Tenant's invoice and documentation; provided, however, to the extent that the total cost of the Tenant Improvements is less than the Tenant Improvement Allowance, Landlord may, by written notice shall have no obligation to provide to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31exceeds the actual cost of the Tenant Improvements. If Landlord fails to fund any portion of the Tenant Improvement Allowance as required under this Work Letter, 2013, shall revert to Landlord and then Tenant shall have no further rights with respect theretomay offset such amount against Rent. EXHIBIT A6.

Tenant Improvement Allowance. Commencing as of January 1, 2011the Execution Date, Tenant shall be entitled to use the “"Tenant Improvement Allowance”", as defined in Section 2 5 of the Summary to this AmendmentLease, for the costs relating to the initial design and construction of Tenant’s improvements 's improvements, which are permanently affixed to the Premises or which are otherwise “"Tenant Improvement Allowance itemsItems,” " as that term is defined in Section 2.2.1, below (collectively, the “"Tenant Improvements”"). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s 's construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s 's property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s 's approval of the “"Final Working Drawings”", as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term Term, or promptly given following any earlier termination of this Lease, at Tenant’s 's expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; , provided, however, that Landlord shall may not require Tenant to remove upon termination any Alterations which are otherwise consistent with typical tenant improvements in the biotechnology or expiration of this Leasepharmaceutical industries. Landlord hereby acknowledges and agrees that the following do not need to be removed if installed: clean suites, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, and any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilitiesoffice space. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 20132020, shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT A.

Tenant Improvement Allowance. Commencing as of January 1Provided Tenant is not in default under this Lease beyond any applicable cure period, 2011, Landlord hereby grants to Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined for use to reimburse Tenant for actual out-of-pocket costs incurred and paid for by Tenant during the period commencing on the Lease Commencement Date and expiring on December 31, 2017 (the "TI Allowance Period") in Section 2 connection with the improvement and/or refurbishment of the Premises pursuant to and in accordance with the terms of this Amendment, for Article 8 (the "Tenant Improvements"). Any costs relating to incurred by Tenant in excess of the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction the performance of the Tenant Improvements or any shall be the sole responsibility of Tenant. Following Tenant's substantial completion of the Tenant Improvement Improvements, Landlord shall reimburse Tenant for the reasonable, actual, third-party, out-of-pocket costs (which costs may include, without limitation, labor and materials costs, professional fees (such as engineers, architects, space planners and interior designers and permitting fees)) incurred by Tenant during the TI Allowance Items, as defined below, Period in a total performing the Tenant Improvements (up to the amount which exceeds the sum of the Tenant Improvement Allowance. All , but after first subtracting a construction oversight fee equal to $7,587.40) within thirty (30) days following Landlord's receipt from Tenant of evidence reasonably satisfactory to Landlord that Tenant has paid for and completed the Tenant Improvements for which in full and in accordance with the terms hereof and that there will be no liens recorded against the Building arising out of or relating to the Tenant Improvement Allowance has been made available Improvements, which evidence shall be deemed Landlordinclude: (a) properly executed, unconditional final mechanic's lien releases from Tenant's architect/space planner, engineers, consultants, contractors, vendors, subcontractors, laborers, and material suppliers retained and/or used by Tenant ("Tenant's Agents"), showing the amounts paid, in compliance with California Civil Code Sections 8132, 8134, 8136 and 8138; (b) Tenant's contractor’s property under the terms last application and certificate for payment (AIA form G702 1992 or equivalent) signed by Tenant's architect/space planner; (c) a breakdown sheet (AIA form G703 1992 or equivalent); (d) original stamped building permit plans; (e) copy of the Leasebuilding permit; provided, however, Landlord may, by written notice to Tenant given concurrently (f) original stamped building permit inspection card with Landlord’s approval all final sign-offs; (g) a CD R disk containing electronic files of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end built” drawings of the Lease Term or promptly following any earlier termination of this LeaseTenant Improvements in both “dwg” and “pdf” formats, at from Tenant's architect/space planner for architectural drawings, and from Tenant's contractor for all other trades; (h) air balance reports; (i) excess energy use calculations; (j) one year warranty letters from Tenant’s expense, to remove any Agents; (k) manufacturer’s warranties and operating instructions; (l) final punchlist completed and signed off by Tenant and Tenant's architect/space planner; (m) letters of compliance from Tenant's engineers stating that the engineers have inspected the Tenant Improvements and to repair that they comply with the engineers' drawings and specifications; (n) a copy of the recorded Notice of Completion; and (o) a final list of all contractors/vendors/consultants retained by Tenant in connection with the Tenant Improvements and any damage to other improvements in the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Section 8.6, which final list shall set forth the full legal name, address, contact name (with telephone/fax/e mail addresses) and the total price paid by Tenant Work Letter (includingfor goods and services to each of such contractors/vendors/consultants; provided that Landlord has determined that no substandard work exists which adversely affects the mechanical, without limitationelectrical, Larc improvements) which constitute standardplumbing, nonheating, ventilating and air conditioning, life-extraordinary improvements for ordinary officesafety or other systems of the Building, laboratory and/or Larc uses the curtain wall of the Building, the structure or exterior appearance of the Building, or any other tenant’s use of such other tenant’s leased premises in biotech facilitiesthe Building. Any Landlord shall have no obligation to disburse any portion of the Tenant Improvement Allowance with respect to any Tenant Improvements that is not disbursed are performed prior to the Lease Commencement Date or allocated for disbursement by December 31after the expiration of the TI Allowance Period, 2013, and any such unused amounts of the Tenant Improvement Allowance as of the end of the TI Allowance Period shall revert to Landlord and Tenant shall have no further rights with respect thereto. EXHIBIT ANotwithstanding the foregoing, at any time during the TI Allowance Period, Tenant shall have the right, subject to the terms of this Section 8.6 and upon not less than thirty (30) days' notice to Landlord, to elect to use any unused amount of the Tenant Improvement Allowance (but in no event an amount in excess of $5.00 per rentable square foot of the Premises) as a credit against the monthly Base Rent otherwise due pursuant to this Lease.

Tenant Improvement Allowance. Commencing as A. Subject to Tenant’s compliance with the provisions of January 1this Exhibit F, 2011, Landlord shall provide to Tenant shall be entitled to use an allowance in the amount of Seven Hundred Thirty Six Thousand Nine Hundred Eleven and 00/100 Dollars ($736,911.00) (the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for ) to construct and install only the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice Tenant shall have the right to Tenant given concurrently with Landlord’s approval utilize (i) up to One Hundred Thirty Six Thousand Four Hundred Sixty Five Dollars ($136,465.00) of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to Tenant Improvement Allowance for the end purchase of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to furniture for the Premises (as evidenced by third party invoices for such furniture costs) and Building caused by such removal and return the affected portion of the Premises to (ii) all or a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed for the tenant improvements being constructed by Tenant at premises owned by affiliates of Landlord and to be leased by Tenant located at 0000 Xxxxxxxx Xxxxxx, Menlo Park, California and 0000 Xxxxxx Xxxx, Xxxxx Xxxx, Xxxxxxxxxx, subject to the terms of the leases between Tenant and such affiliates of Landlord. The Tenant Improvement Allowance shall be used to design, prepare, plan, obtain the approval of, construct and install the Tenant Improvements and for no other purpose. Except as otherwise expressly provided herein, Landlord shall have no obligation to contribute the Tenant Improvement Allowance unless and until the Construction Documents have been approved by Landlord and Tenant has complied with all requirements set forth in Paragraph 4.C. of this Exhibit F. In addition to the foregoing, Landlord shall have no obligation to disburse all or allocated for disbursement by any portion of the Tenant Improvement Allowance to Tenant unless Tenant makes a progress payment request pursuant to the terms and conditions of Section 5.B. below prior to December 31, 20132012 (time being of the essence). The costs to be paid out of the Tenant Improvement Allowance shall include all reasonable costs and expenses associated with the design, shall revert to Landlord preparation, approval, planning, construction and installation of the Tenant shall have no further rights with respect thereto. EXHIBIT AImprovements (the “Tenant Improvement Costs”), including all of the following:

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use a one-time tenant improvement allowance (the “"Tenant Improvement Allowance”") in the amount of up to, as defined in Section 2 of this Amendmentbut not exceeding $700,000.00, for the costs relating Tenant Improvements; provided, however, that Landlord shall have no obligation to disburse all or any portion of the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as to Tenant unless Tenant makes requests for disbursement pursuant to the terms and conditions of Section 2.3 below prior to December 31, 2018 (the “Request Deadline”); provided that term is defined in Section 2.2.1, below (collectivelythe event Bridgepoint refuses to allow Tenant to proceed with the Tenant Improvements for any reason, the “Request Deadline will be extended to the extent necessary to allow Tenant Improvements”)to complete the Tenant Improvements within the Term of this Lease. In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of [FINAL EXECUTION COPY]SMRH:478611488.18 EXHIBIT B-1- 600 B STREETMitek Systems, Inc. 92917 35XW-244846 the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, Except as that term is defined in Section 3.3, specifically set forth below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant be entitled to remove upon termination receive any cash payment or expiration of this Lease, credit against Rent or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, otherwise for any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any unused portion of the Tenant Improvement Allowance that which is not disbursed or allocated used to pay for disbursement the Tenant Improvement Allowance Items (as such term is defined below). Any balance of the Tenant Improvement Allowance not requested by December 31, 2013Tenant in accordance with the terms and conditions of this Work Letter by the Request Deadline, shall revert to Landlord be deemed forfeited by Tenant and Tenant shall have no further rights with respect thereto. EXHIBIT ANotwithstanding anything contained in this Work Letter or the Lease to the contrary, the Tenant Improvement Allowance will be disbursed to Tenant subject to and in accordance with this Work Letter, and the terms of this Work Letter will apply to any construction in the Premises, during the term of the Sublease (as defined in Section 2.2 of the Lease), provided, however, Tenant shall obtain Bridgepoint’s consent to the commencement of construction of the Tenant Improvements hereunder prior to the expiration of the Bridgepoint Lease.

Tenant Improvement Allowance. Commencing as The cost of January 1, 2011, Tenant shall be entitled to use the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of constructing the Tenant Improvements or any Tenant Improvement Allowance Items(including but not limited to the costs for plans, permits and fees as defined below, more particularly described in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available Exhibit D) shall be deemed paid by Landlord’s property under the terms of the Lease; provided, however, if the amount expended for constructing the Tenant Improvements is or will be more than $1,450,000, Tenant hereby agrees to reimburse Landlord mayfor all costs incurred in connection with the Tenant Improvements except for $1,450,000 which is the Landlord's allowance (the "Allowance") and, by written notice to except as otherwise provided herein, is Landlord's entire monetary obligation for the Tenant given concurrently with Landlord’s approval Improvements; and provided, further, any excess costs incurred as a result of the “Final Working Drawings”fault or neglect of Landlord or of Landlord's contractors, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term employees or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused agents shall be borne entirely by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance that is not disbursed or allocated for disbursement by December 31, 2013, shall revert to Landlord and Tenant shall be responsible for all costs incurred in connection with Landlord's Work as a result of the fault or neglect of Tenant. Tenant shall pay any costs which are Tenant's responsibility hereunder (the "Excess Costs") on a pro rata basis with Landlord's payments for design and construction of the Tenant Improvements, so that Landlord will always have no further rights paid a share of the total costs then incurred which is equal to the percentage which the Allowance is of the sum of the Allowance and Excess Costs, as then determined, and Tenant will always have paid a share of the total costs for the Tenant Improvements then incurred which is equal to the percentage which the Excess Costs, as then determined, is to the sum of the Allowance and the Excess Costs, as then determined. Determination(s) of the amount of the Excess Costs may be made from time to time prior to, during or after construction. Tenant shall make such payments, including any adjustments necessary to maintain the Tenant's appropriate share of the total costs as a result of subsequent determinations, based upon requisitions setting forth in reasonable detail the reason for such Excess Costs and the amount thereof, together with respect theretoany other information reasonably requested by Tenant, and the amounts owing by Tenant shall be paid by Tenant to Landlord within ten (10) days after receipt of each such requisition and other information. EXHIBIT AExcept as otherwise provided herein, Tenant shall have complete responsibility for the cost of the Tenant Improvements and for the construction by Tenant of any other improvements and alterations to the Premises in connection with Tenant's occupancy thereof, Tenant agreeing to accept the same "AS IS", subject only to the construction by Landlord of the Tenant Improvements and any other obligation of Landlord under this Lease. Landlord shall promptly furnish to Tenant estimates of the anticipated costs of the various elements of the Tenant Improvements as such estimates are received by Landlord. If Tenant believes that the amount of any estimate is excessive Tenant may request changes in the Tenant Improvement Plans in accordance with subparagraph (d) above. On or before sixty (60) days after completion of the Tenant Improvements, Landlord will provide a final reconciliation of the Allowance, the Excess Costs and the total costs of the Tenant Improvements and each party shall promptly thereafter make any payment to the other party which is necessary to effect the correct allocation of the total costs of the Tenant Improvements as provided in this subparagraph.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the Lease or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011the cost of construction of the Tenant Improvements shall be paid or reimbursed by Landlord up to a maximum amount equal to $2,119,095.00 (the "Tenant Improvement Allowance"), which amount is being made available by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Premises. Tenant shall be responsible, at its sole cost and expense, for payment of the entire Cost of Improvements of the Tenant Improvements in excess of the Tenant Improvement Allowance, including (but not limited to) any costs or cost increases incurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “entire Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, toward the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction Cost of Improvements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or any Tenant Improvement Allowance Items, as defined below, charges set forth in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to in this Tenant Work Letter (including, without limitation, Larc improvementsLetter) which constitute standard, non-extraordinary improvements prior to being required to expend any of Tenant’s own funds for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe Tenant Improvements. Any portion The funding of the Tenant Improvement Allowance that is not disbursed shall be made on a monthly basis or allocated for disbursement at other convenient intervals mutually approved by December 31, 2013, shall revert to Landlord and Tenant and in all other respects shall have be based on such commercially reasonable disbursement conditions and procedures as Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no further rights circumstances shall the Tenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for any Cost of Improvement (or any other cost or expense) associated with any moveable furniture or trade fixtures, personal property or any other item or element which, under the applicable provisions of the Lease, will not become Landlord’s property and remain with the Building upon expiration or termination of the Lease. Notwithstanding anything to the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for and the Tenant Improvement Allowance shall not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials, if any, but with respect thereto. to removal and remediation of any such Hazardous Materials, only to the extent such removal or remediation is required by Applicable Laws enforced as of the date of this Lease for improvements in the Premises generally (as opposed to the specific Tenant Improvements) and to the extent the same required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary occupancy density;(b) costs to bring the Project into compliance with Applicable Laws to the extent required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary office occupancy density; (c) construction costs in excess of the contract amount stated in the contract with the General Contractor, as approved by Tenant (not to be unreasonably withheld), except for increases set forth in change orders approved by Tenant; (d) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed); (e) attorneys' fees incurred in connection with negotiation of construction contracts, and attorneys' fees, experts' fees and other costs in connection with disputes with third parties; (f) interest and other costs of financing construction costs; (g) costs incurred as a consequence construction defects or default by a contractor; (h) costs as a consequence of casualties; (i) penalties and late charges attributable to Landlord’s failure to pay construction costs, and (j) costs due to compliance with any soil management plan for the Project or its appendices 8377633.2 (8383465.1) EXHIBIT AB -0- Xxxxxxx Xxxxx Xxxx I Limited Partnership [Britannia Point Eden] [Pulse Biosciences, Inc.]

Tenant Improvement Allowance. Commencing as of January 1, 2011, Tenant shall be entitled to use construct and install the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction of the Tenant Improvements or any Tenant Improvement Allowance Items, as defined below, in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s sole cost and expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that if Tenant is not in default under the Lease on the Expansion Commencement Date, then Landlord shall contribute an improvement allowance equal to (i) Ten and 00/100 Dollars ($10.00) per rentable square foot for the Improvement Work in the Expansion Premises (i.e., $42,190.00) (“Expansion Premises Allowance”), and (ii) One and 50/100 Dollars ($1.50) per rentable square foot for the Improvement Work in the Original Premises (i.e., $19,198.50) (“Original Premises Allowance”), for a total allowance of Sixty-One Thousand Three Hundred Eighty-Eight and 50/100 Dollars ($61,388.50) (collectively, “Fourth Amendment Allowance”). The Expansion Premises Allowance shall be used only for Improvement Work in the Expansion Premises and the Original Premises Allowance shall be used only for Improvement Work in the Original Premises. In addition, Tenant has an unused tenant improvement allowance pursuant to the Third Amendment to Lease in the amount of up to Thirty-Eight Thousand Three Hundred Ninety-Seven ($38,397.00) (“Third Amendment Allowance”). The Third Amendment Allowance may be used only for Improvement Work in the Original Premises. Notwithstanding the foregoing, Tenant may use the Third Amendment Allowance to pay for improvements that Tenant has made to the Original Premises prior to the Fourth Amendment Date (“Third Amendment Improvement Work”); provided, however, that in seeking reimbursement for the cost of the Third Amendment Improvement Work Tenant complies with all requirements regarding the reimbursement of the costs for the Improvement Work set forth in this Work Letter. The Fourth Amendment Allowance and the Third Amendment Allowance (collectively, “Allowance”) shall not be used for any rent credit or for the purchase or installation of any of Tenant’s furniture, fixtures, equipment, personal property, cabling or communications systems. The Allowance shall be paid to Tenant within thirty (30) days following receipt by Landlord of (a) payment receipts covering all labor and materials expended and used in the construction and installation of the Improvement Work; (b) copies of lien waivers from all contractors and materialmen in statutory form; (c) a sworn contractor’s affidavit from the general contractor and a request to disburse from Tenant containing an approval by Tenant of the Improvement Work as completed; (d) as-built plans of the Improvement Work; (e) the written certification of Tenant and its architect that the Improvement Work has been constructed and installed in a good and workmanlike manner in accordance with the Construction Drawings and applicable building codes, ordinances, laws or regulations; (f) a duly issued, written certificate of occupancy and/or equivalent final inspection by the governmental agency having jurisdiction relative to occupancy of the Expansion Premises and the completion of the Improvement Work; (g) reasonable written evidence that all permit and approval fees relating to the construction and installation of the Improvement Work have been paid by Tenant; and (h) copies of all construction warranties and guarantees relating to construction of the Improvement Work, if any, and an assignment to Landlord on a non-exclusive basis of all of such warranties and guaranties, to the extent assignable. The Expansion Premises Allowance shall be disbursed in the amount reflected on the payment receipts for the Improvement Work in the Expansion Premises that meet the requirements above. The Original Premises Allowance shall be disbursed in the amount reflected on the payment receipts for the Improvement Work in the Original Premises that meet the requirements above. The Third Amendment Allowance shall be disbursed in the amount reflected on the payment receipts for the Improvement Work in the Original Premises and the Third Amendment Improvement Work that meet the requirements above. Notwithstanding any provision of the Lease to the contrary, Landlord shall not require Tenant be obligated to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, disburse any Tenant Improvements constructed pursuant to this Tenant Work Letter (including, without limitation, Larc improvements) which constitute standard, non-extraordinary improvements for ordinary office, laboratory and/or Larc uses in biotech facilities. Any portion of the Tenant Improvement Allowance during the continuance of an uncured default under the Lease, and Landlord’s obligation to disburse shall resume only when and if such default is cured. In the event that the Expansion Premises Allowance is not disbursed or allocated sufficient to pay for disbursement by December 31the entire cost to complete the Improvement Work in the Expansion Premises, 2013, shall revert to Landlord and then Tenant shall have no further rights pay any and all excess costs related to such Improvement Work. Tenant acknowledges that neither the Original Premises Allowance nor the Third Amendment Allowance can be applied to any such excess costs for the Improvement Work in the Expansion Premises. In the event that the Original Premises Allowance and the Third Amendment Allowance are not sufficient to pay for the entire cost to complete the Improvement Work in the Original Premises, then Tenant shall pay any and all excess costs related to such Improvement Work. Tenant acknowledges that the Expansion Premises Allowance cannot be applied to any such excess costs for the Improvement Work in the Original Premises. In the event that the Expansion Premises Allowance exceeds the cost of the Improvement Work in the Expansion Premises, or if the full Expansion Premises Allowance amount is not applied to the cost of the Improvement Work in the Expansion Premises within twelve (12) months after the Expansion Commencement Date, then any remaining portion of the Expansion Premises Allowance shall accrue to the sole benefit of Landlord, it being agreed that Tenant shall not be entitled to any credit, offset, abatement or payment with respect thereto. EXHIBIT AIn the event that the Original Premises Allowance exceeds the cost of the Improvement Work in the Original Premises, or if the full Original Premises Allowance amount is not applied to the cost of the Improvement Work in the Original Premises within twelve (12) months after the Expansion Commencement Date, then any remaining portion of the Original Premises Allowance shall accrue to the sole benefit of Landlord, it being agreed that Tenant shall not be entitled to any credit, offset, abatement or payment with respect thereto. In the event that the Third Amendment Allowance exceeds the cost of the Improvement Work in the Original Premises and the Third Amendment Improvement Work, or the full Third Amendment Allowance is not applied to the cost of the Improvement Work in the Original Premises or the Third Amendment Improvement Work within twelve (12) months after the Expansion Commencement Date, then any remaining portion of the Third Amendment Allowance shall accrue to the sole benefit of Landlord, it being agreed that Tenant shall not be entitled to any credit, offset, abatement or payment with respect thereto. Landlord shall be entitled to deduct from the Fourth Amendment Allowance a construction management fee for Landlord’s oversight and supervision of the Improvement Work in an amount equal to two percent (2%) of the disbursed portion of the Fourth Amendment Allowance. Pursuant to the Third Amendment, Landlord shall be entitled to deduct from the Third Amendment Allowance a construction management fee for Landlord’s oversight and supervision of the Improvement Work and the Third Amendment Improvement Work in an amount equal to three percent (3%) of the disbursed portion of the Third Amendment Allowance.

Tenant Improvement Allowance. Commencing Subject to any restrictions, conditions or limitations expressly set forth in this Tenant Work Letter or in the Lease or as otherwise expressly provided by mutual written agreement of January 1Landlord and Tenant, 2011the cost of construction of the Tenant Improvements shall be paid or reimbursed by Landlord up to a maximum amount equal to $10,283,355.00 (the “Tenant Improvement Allowance”), which amount is being made available by Landlord to be applied towards the Cost of Improvements for the construction of the Tenant Improvements in the Premises. Tenant shall be responsible, at its sole cost and expense, for payment of the entire Cost of Improvements of the Tenant Improvements in excess of the Tenant Improvement Allowance, including (but not limited to) any costs or cost increases incurred as a result of delays (unless caused by Landlord), governmental requirements or unanticipated conditions (unless caused by Landlord), and for payment of any and all costs and expenses relating to any alterations, additions, improvements, furniture, furnishings, equipment, fixtures and personal property items which are not eligible for application of Tenant Improvement Allowance funds under the restrictions expressly set forth below in this paragraph, but Tenant shall be entitled to use or apply the “Tenant Improvement Allowance”, as defined in Section 2 of this Amendment, for the costs relating to the design and construction of Tenant’s improvements or which are otherwise “entire Tenant Improvement Allowance items,” as that term is defined in Section 2.2.1, below (collectively, toward the “Tenant Improvements”). In no event shall Landlord be obligated to make disbursements pursuant to this Tenant Work Letter or otherwise in connection with Tenant’s construction Cost of Improvements of the Tenant Improvements (subject to any applicable restrictions, conditions, limitations, reductions or any Tenant Improvement Allowance Items, as defined below, charges set forth in a total amount which exceeds the sum of the Tenant Improvement Allowance. All Tenant Improvements for which the Tenant Improvement Allowance has been made available shall be deemed Landlord’s property under the terms of the Lease; provided, however, Landlord may, by written notice to Tenant given concurrently with Landlord’s approval of the “Final Working Drawings”, as that term is defined in Section 3.3, below, require Tenant, prior to the end of the Lease Term or promptly following any earlier termination of this Lease, at Tenant’s expense, to remove any Tenant Improvements and to repair any damage to the Premises and Building caused by such removal and return the affected portion of the Premises to a Building standard general office condition; provided, however, that Landlord shall not require Tenant to remove upon termination or expiration of this Lease, or condition its approval upon Tenant’s agreement to remove upon termination or expiration of this Lease, any Tenant Improvements constructed pursuant to in this Tenant Work Letter (including, without limitation, Larc improvementsLetter) which constitute standard, non-extraordinary improvements prior to being required to expend any of Tenant’s own funds for ordinary office, laboratory and/or Larc uses in biotech facilitiesthe Tenant Improvements. Any portion The funding of the Tenant Improvement Allowance that is not disbursed shall be made on a monthly basis or allocated for disbursement at other convenient intervals mutually approved by December 31, 2013, shall revert to Landlord and Tenant and in all other respects shall have be based on such commercially reasonable disbursement conditions and procedures as Landlord, Project Manager and Landlord’s lender (if any) may reasonably prescribe. Notwithstanding the foregoing provisions, under no further rights circumstances shall the Tenant Improvement Allowance or any portion thereof be used or useable by Tenant for any moving or relocation expenses of Tenant, or for any Cost of Improvement (or any other cost or expense) associated with any moveable furniture or trade fixtures, personal property or any other item or element which, under the applicable provisions of the Lease, will not become Landlord’s property and remain with the Building upon expiration or termination of the Lease. Notwithstanding anything to EXHIBIT B the contrary herein, the Tenant Improvements shall not include (and Landlord shall be solely responsible for and the Tenant Improvement Allowance shall not be used for) the following: (a) costs incurred due to the presence of any Hazardous Materials in the Premises, if any, but with respect thereto. EXHIBIT Ato removal and remediation of any such Hazardous Materials, only to the extent such removal or remediation is required by Applicable Laws enforced as of the date of this Lease for improvements in the Premises generally (as opposed to the specific Tenant Improvements) and to the extent the same required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary occupancy density; (b) costs to bring the Project into compliance with Applicable Laws to the extent required in order to allow Tenant to obtain a certificate of occupancy or its legal equivalent, for the Premises for the Permitted Use assuming a normal and customary office occupancy density; (c) construction costs in excess of the contract amount stated in the contract with the General Contractor, as approved by Tenant (not to be unreasonably withheld), except for increases set forth in change orders approved by Tenant; (d) wages, labor and overhead for overtime and premium time unless approved by Tenant (which approval shall not be unreasonably withheld, conditioned or delayed); (e) attorneys’ fees incurred in connection with negotiation of construction contracts, and attorneys’ fees, experts’ fees and other costs in connection with disputes with third parties; (f) interest and other costs of financing construction costs; (g) costs incurred as a consequence construction defects or default by a contractor; (h) costs as a consequence of casualties; and (i) penalties and late charges attributable to Landlord’s failure to pay construction costs.