Supply Agreement

Collaboration and Global Supply Agreement

by Immunex Corp /De/
November 13th, 2001


                                                                    Exhibit 10.2

* Certain confidential information contained in this document, marked by
brackets, has been omitted and filed with the Securities and Exchange Commission
pursuant to Rule 406 of the Securities Act of 1933, as amended. The omitted
portions of this exhibit have been filed separately with the Securities and
Exchange Commission.

                    COLLABORATION AND GLOBAL SUPPLY AGREEMENT

                                 By and Between

                               IMMUNEX CORPORATION

                                       and

              AMERICAN HOME PRODUCTS CORPORATION acting through its
                     WYETH-AYERST PHARMACEUTICALS division




                    COLLABORATION AND GLOBAL SUPPLY AGREEMENT

This COLLABORATION AND GLOBAL SUPPLY AGREEMENT (the "Agreement") is entered into
this 6th day of November, 2001 (the "Effective Date"), by and between IMMUNEX
CORPORATION, a Washington corporation having its principal place of business at
51 University Street, Seattle, Washington 98101, together with its Affiliates
(collectively, "Immunex") and AMERICAN HOME PRODUCTS CORPORATION, a Delaware
corporation having its corporate headquarters at Five Giralda Farms, Madison,
New Jersey 07940, together with its Affiliates (collectively, "AHPC"), acting
through its WYETH-AYERST PHARMACEUTICALS division, having offices at 555 East
Lancaster Avenue, St. Davids, Pennsylvania 19087, together with its Affiliates
(collectively, "Wyeth").

                                   Background

WHEREAS, Immunex and AHPC entered into a TNFR License and Development Agreement
dated July 1, 1996 (the "TNFR Agreement"), in which they agreed to collaborate
as set forth in the TNFR Agreement with regard to Enbrel(R) (etanercept)
("Enbrel"), a biopharmaceutical product for the treatment of rheumatoid
arthritis and other diseases;

WHEREAS, in the TNFR Agreement, the Parties agreed that Immunex would have
certain rights to market and sell Enbrel in the United States, its territories
and possessions (including Puerto Rico), and Canada, and that Wyeth would have
certain rights to market and sell Enbrel in all other countries;

WHEREAS, Immunex and AHPC entered into a Promotion Agreement dated September 25,
1997, regarding the marketing and promotion of Enbrel in the Immunex Territory
(the "Promotion Agreement");

WHEREAS, Immunex and AHPC entered into an Enbrel Supply Agreement with
Boehringer Ingelheim Pharma KG (including any successor thereto, "BIP") dated
November 5, 1998, which agreement was amended by Amendment No. 1 to the Enbrel
Supply Agreement dated June 27, 2000, in which BIP agreed to manufacture certain
quantities of Enbrel and supply those quantities to Immunex and Wyeth;

WHEREAS, Greenwich Holdings, Inc. ("Greenwich"), a wholly-owned subsidiary of
AHP Subsidiary Holding Corporation ("AHPS"), a wholly-owned subsidiary of AHPC,
owns a manufacturing facility located in West Greenwich, Rhode Island at which
Enbrel is expected to be manufactured;

WHEREAS, Immunex, AHPC, and AHPS have entered into a Purchase Agreement
simultaneously with this Agreement, pursuant to which AHPS is obligated to sell,
and Immunex is obligated to purchase, the shares of Greenwich;




WHEREAS, AHP Manufacturing B.V., a wholly-owned indirect subsidiary of AHPC,
through its Wyeth Medica Ireland branch, is in the process of constructing a
manufacturing facility in Ireland, at which it plans to manufacture Enbrel,
among other products;

WHEREAS, the Parties entered into a letter agreement regarding the short-term
allocation of Enbrel supplies dated August 9, 2000 (the "Short-Term Allocation
Agreement"), which agreement is attached hereto as Exhibit C;

WHEREAS, the Parties agreed, in a Memorandum of Understanding Regarding
Long-Term Allocation of ENBREL Supplies dated August 9, 2000, as amended on
April 18, 2001 (the "MOU"), to enter into a Collaboration Agreement regarding
the manufacture, inventory, and allocation of supplies of Enbrel throughout the
world, which MOU is superceded by this Agreement and is of no further force and
effect; and

WHEREAS, the Parties now wish to set forth their mutual agreements concerning
the manufacture, supply, inventory, and allocation of supplies of Enbrel
throughout the world.

NOW THEREFORE, in consideration of the mutual covenants contained herein, and
for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the Parties do hereby agree as follows:

                             Article 1. Definitions

The following terms, whether used in the singular or the plural, shall have the
meaning assigned to them below for purposes of this Agreement.

1.1   "Affiliate" shall mean: (a) any corporation or business entity of which a
      Party owns, directly or indirectly, fifty percent (50%) or more of the
      assets or outstanding stock; (b) any corporation, or business entity which
      a Party directly or indirectly controls; (c) any corporation or business
      entity that is under common control with a Party; (d) any corporation or
      business entity that owns, directly or indirectly, fifty percent (50%) or
      more of the assets or outstanding stock of a Party; or (e) any corporation
      or business entity that directly or indirectly controls a Party. For the
      purposes of this Agreement, neither Party shall be considered to be an
      Affiliate of the other Party, even if a Party owns, directly or
      indirectly, fifty (50%) or more of the assets or outstanding stock of the
      other Party, directly or indirectly controls the other Party, or is under
      common control with the other Party.

1.2   "Allocable Overhead" shall mean costs allocated to the manufacture of Bulk
      Drug Substance based on methodology consistently applied in the project
      accounting system and determined in accordance with GAAP. Allocable
      Overhead shall include:


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      (i)   indirect labor, benefits and taxes, indirect supplies, outside
            laboratory services, laboratory and plant consumables, and other
            indirect department expenses;

      (ii)  facility costs such as rent, depreciation (excluding depreciation of
            capitalized interest), utilities, facility repair and maintenance
            and monitoring;

      (iii) other overhead costs, including infrastructure services, purchasing,
            information systems, accounting, period costs, and other related
            expenses; and

      (iv)  such other costs as the Parties may agree upon in writing from time
            to time.

      An example of the methodology to be used in calculating Allocable Overhead
      is included in Exhibit A attached hereto. Allocable Overhead shall not
      include any costs attributable to general corporate activities, including
      but not limited to executive management, investor relations, business
      development, legal affairs, and finance.

1.3   "BIOS Capacity" shall mean the volume of Bulk Drug Substance that the
      Parties reasonably expect to be manufactured within bioreactors having a
      working volume equivalent to the RI Capacity during a Calendar Year.

1.4   "BIOS Site" shall mean the portion of the biopharmaceutical manufacturing
      facility to be built at the Wyeth BioPharma campus at Grange Castle
      International Business Park, Clondalkin, Dublin 22, Ireland, within which
      the BIOS Capacity will be manufactured. The BIOS Site shall not include
      such manufacturing facility with respect to its manufacture of Excluded
      Supply or products other than the Product.

1.5   "BIP Capacity" shall mean the volume of Bulk Drug Substance that Immunex
      and Wyeth reasonably expect to purchase collectively from BIP pursuant to
      the Enbrel Supply Agreement during a Calendar Year, excluding any Bulk
      Drug Substance from Bulk Drug Substance Runs that have been separately
      negotiated pursuant to an agreement between only one of the Parties hereto
      and a Third Party customer of BIP on or before March 26, 2001.

1.6   "BIP Site" shall mean that portion of BIP's facility at Birkendorfer
      Stra(beta)e 65, 88397 Biberach an der Riss, Federal Republic of Germany,
      within which the BIP Capacity is or will be manufactured, including but
      not limited to the [*], during a Calendar Year. In the event that the
      manufacture of the Product is transferred to another facility of BIP, a
      BIP Affiliate, or a successor of BIP in accordance with the terms of the
      Enbrel Supply Agreement, then the BIP Site shall refer to that portion of
      such successor facility in which the BIP Capacity is manufactured.

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1.7   "Blended Price" shall mean the price for Bulk Drug Substance that is
      calculated as [*] for each of the Sites for a Calendar Year, as further
      described in Section 9.3 below. An example of the calculation of the
      Blended Price is set forth on Exhibit A attached hereto.

1.8   "Bulk Drug Substance" shall mean etanercept that has been processed to
      result in bulk drug substance and purified to a concentrated form, and
      that can be stored in liquid or frozen form under appropriate conditions.

1.9   "Bulk Drug Substance Lot" shall mean a single lot of Bulk Drug Substance,
      produced at a fermentation scale of [*], or any other scale mutually
      agreed by the Parties.

1.10  "Bulk Drug Substance Run" shall mean a single run of the process for
      manufacturing a Bulk Drug Substance Lot.

1.11  "Calendar Quarter" shall mean a three (3)-month period commencing on the
      first day of January, April, July, and October of each Calendar Year
      during the Term.

1.12  "Calendar Year" shall mean a twelve (12)-month period beginning on January
      1 of each year during the Term.

1.13  "Catalytica Supply Agreement" shall mean the Supply Agreement, dated
      October 16, 2000, among Immunex, Wyeth, and Catalytica Pharmaceuticals,
      Inc. (including any successor thereto, "Catalytica").

1.14  "cGMP" shall mean the regulatory requirements for current good
      manufacturing practices promulgated by the FDA under the FD&C Act, 21
      C.F.R.ss.210 et seq., and under the PHS Act, Biological Products, 21
      C.F.R.ss.ss.600-610, or the applicable regulatory guidance documents
      promulgated by the EMEA or Koseisho, as the same may be amended from time
      to time.

1.15  "Collaboration" shall mean the collaborative efforts of the Parties as
      further described herein.

1.16  "Confidential Information" shall mean all proprietary and confidential
      information of a Party, including, without limitation, trade secrets,
      technical information, business information, sales information, customer
      and potential customer lists and identities, product sales plans, license
      and sublicense agreements, inventions, developments, discoveries,
      know-how, methods, techniques, formulae, data, processes, and other
      proprietary ideas, whether or not protectable under patent, trademark,
      copyright, or other legal principles, that the other Party has access to
      or receives, but does not include information that (a) is or becomes
      publicly available through no fault of the receiving Party; (b) was
      already known to the receiving Party at the time it was disclosed to the
      receiving Party, as shown in the records of the receiving Party maintained
      during the ordinary course of business; (c) is independently developed by
      employees of the

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      receiving Party who had no knowledge of or access to such information, as
      shown in the records of the receiving Party maintained in the ordinary
      course of business; or (d) is received from a Third Party who is under no
      obligation of confidentiality to the disclosing Party. As used herein,
      "Confidential Information" shall include, without limitation, any and all
      technical information regarding the Product, Five-Year Requirement
      Schedules, Five-Year Capacity Projections, and Five-Year Plans.

1.17  "Direct Costs" shall include: (a) direct labor costs, which shall include
      all wages directly attributable and allocable to labor for the production
      of Bulk Drug Substance at the RI Site and the BIOS Site, as applicable;
      and (b) material costs, including the costs of acquiring all materials
      directly attributable and allocable to the production of Bulk Drug
      Substance at the RI Site and the BIOS Site, as applicable.

1.18  "Drug Product" shall mean Bulk Drug Substance that has been appropriately
      formulated, compounded, filled into containers and lyophilized (if
      applicable), but is not labeled (i.e., unlabeled vial or syringe packed in
      a labeled secondary shipper).

1.19  "EMEA" shall mean the European Medicines Evaluation Agency, or any
      successor agency.

1.20  "Enbrel Supply Agreement" shall mean the November 5, 1998 agreement among
      Immunex, BIP, and AHPC for the manufacture of Product at the BIP Facility,
      as amended on June 27, 2000 and as may be amended from time to time by the
      parties thereto.

1.21  "European Union" shall mean those countries within the jurisdiction of the
      EMEA.

1.22  "Excluded Supply" shall mean (a) any quantities of Product manufactured or
      acquired by Immunex outside of the RI Capacity or BIP Capacity, and (b)
      any quantities of Product manufactured or acquired by Wyeth outside of the
      BIOS Capacity or the BIP Capacity.

1.23  "FDA" shall mean the United States ("U.S.") Food and Drug Administration,
      or any successor agency.

1.24  "Finished Product" shall mean Drug Product in a vial or syringe that has
      been appropriately labeled and that is suitable for shipment in bulk
      packaging to Immunex, Wyeth and/or their respective designee(s) for final
      commercial packaging and conversion to Product Supply.

1.25  "Fully Absorbed Manufacturing Cost" shall have the meanings set forth
      below:

      (a)   For Bulk Drug Substance manufactured at the RI Site or the BIOS
            Site, Fully Absorbed Manufacturing Cost shall mean [*] of all costs,
            expenses, and period costs incurred at the Site for the
            manufacturing of Bulk Drug Substance

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            incurred by the Party controlling such Site, determined according to
            GAAP and as mutually agreed upon by the Parties. Such costs shall
            include Direct Costs and Allocable Overhead at each stage of the
            process for manufacturing Bulk Drug Substance at such Site. Fully
            Absorbed Manufacturing Cost shall also include any other costs borne
            by the Party controlling such Site for transport, customs clearance
            and storage of Bulk Drug Substance (if necessary) at the request of
            another Party or a Third Party (i.e., freight, customs duty, and
            transportation related insurance). Fully Absorbed Manufacturing Cost
            shall exclude any losses at the RI Site or BIOS Site resulting from
            a significant or catastrophic event that would otherwise be covered
            by property insurance, regardless of whether such insurance is in
            place. To the extent that the manufacturing capacity at the RI Site
            or BIOS Site is utilized to manufacture a product other than the
            Product, the Direct Costs and Allocable Overhead incurred for the
            manufacture of such other product shall be excluded from the
            calculation of Fully Absorbed Manufacturing Cost.

      (b)   For Bulk Drug Substance manufactured at the BIP Site, Fully Absorbed
            Manufacturing Cost shall mean the amount paid or payable by a Party
            to BIP for Bulk Drug Substance purchased by a Party under the Enbrel
            Supply Agreement, whether purchased in the form of Bulk Drug
            Substance itself or as incorporated into Drug Product or Finished
            Product, as the case may be.

      An example of the calculation of Fully Absorbed Manufacturing Cost is
      included in Exhibit A attached hereto.

1.26  "GAAP" shall mean U.S. Generally Accepted Accounting Principles
      consistently applied.

1.27  [*]

1.28  [*]

1.29  "Immunex Territory" shall mean the U.S., its territories and possessions
      (including Puerto Rico) and Canada.

1.30  "Inventory Carrying Costs" shall mean [*] per annum of the Fully Absorbed
      Manufacturing Cost of Bulk Drug Substance manufactured at either the RI
      Site or the BIOS Site, as applicable, and held in storage by or on behalf
      of a Party for a period greater than [*] days after release by both
      Parties, commencing after such [*]-day period has elapsed.

1.31  [*] shall mean the Immunex proprietary process for manufacturing Bulk Drug
      Substance, which, if used at the RI Site, shall include the [*], and which
      process is the subject of a letter agreement among Immunex, Wyeth, and BIP
      dated May 29, 2001.

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1.32  "Major Markets" shall mean the U.S., the European Union, and Japan.

1.33  "Manufacturing Process" shall mean a process for manufacturing Bulk Drug
      Substance and/or Drug Product, including but not limited to the T1
      Process, the [*], and the T2 Process.

1.34  "Party" or "Parties" shall refer to Immunex, AHPC, and/or Wyeth, as
      applicable.

1.35  "Phase A Capacity" shall mean the volume of Bulk Drug Substance that the
      Parties reasonably expect to be manufactured within the [*] liter nominal
      volume bioreactors contained in the Phase A Facility during a Calendar
      Year, or, if Immunex transfers such manufacturing to the Phase B Facility,
      the volume of Bulk Drug Substance that the Parties reasonably expect to be
      manufactured within bioreactors of equivalent working volume in the Phase
      B Facility during a Calendar Year.

1.36  "Phase A Facility" shall mean the manufacturing plant at the RI Site that
      Wyeth is currently in the process of retrofitting to manufacture Bulk Drug
      Substance.

1.37  "Phase B Additional Capacity" shall mean the volume of Bulk Drug Substance
      that the Parties reasonably expect to be manufactured within [*] liter
      nominal volume bioreactors in the Phase B Facility per Calendar Year.

1.38  "Phase B Facility" shall mean the new manufacturing facility that Immunex
      plans to construct located on the portion of the RI Site that Immunex
      Manufacturing Corporation has leased from Greenwich pursuant to the Ground
      Lease between those parties dated March 9, 2001.

1.39  "Product" shall mean the pharmaceutical product etanercept, in any form.

1.40  "Product Supply" shall mean Finished Product that has been fully packaged
      and is in final form for distribution for commercial sale or clinical
      testing in any country in the Immunex Territory or the Wyeth Territory.

1.41  "Product Supply Units" shall refer to individual units of Product Supply.

1.42  "Production Surplus" shall mean the situation, as may be determined by the
      JSC from time to time, in which the Parties' forecasted needs for Product
      Supply in any Calendar Year fall more than [*] below the total quantity of
      Bulk Drug Substance that can be manufactured in the Subject Capacity
      during such Calendar Year.

1.43  "Quality Agreement" shall mean the Quality Agreement attached hereto as
      Exhibit D, as the same may be amended from time to time, setting forth the
      terms and conditions relating to (a) the quality, safety, efficacy, and
      purity of the Bulk Drug Substance supplied by each Party to the other
      hereunder, (b) the respective roles and

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      responsibilities of Immunex and Wyeth relating to quality control, quality
      assurance, validation, ongoing manufacturing, materials, standards, and
      the functions of person(s)-in-the-plant, and (c) procedures for resolving
      disputes regarding any of the foregoing.

1.44  "Regulatory Authority" shall mean (a) the applicable government agency or
      agencies in a country whose permission, approval, or clearance must be
      obtained for, or which has jurisdiction over, the manufacturing,
      production, clinical testing, and/or marketing of the Product, including,
      but not limited to, the FDA, the EMEA, and Koseisho; and (b) any state,
      provincial, or local government agency or entity with jurisdiction, to any
      extent, over the Party supplying the Product, a Site, or the Product.

1.45  "Regulatory Filings" shall mean all documents and other information filed
      with and/or submitted to one or more Regulatory Authorities and which are
      related to the Product.

1.46  "Regulatory Requirements" shall mean (a) all Specifications, methods of
      manufacture, and other information in one or more Regulatory Filings in a
      Major Market related in any way to the Product, and (b) all laws, rules,
      regulations, applicable regulatory guidance documents, and other
      requirements of any Regulatory Authority in a Major Market that govern the
      Product, the manufacture of the Product, and use of the Product in or with
      Finished Products, including, but not limited to, the requirements set
      forth in the United States Federal Food, Drug, and Cosmetic Act (the "FD&C
      Act"), 21 U.S.C. Section 301 et seq., the Public Health Service Act (the
      "PHS Act"), 42 U.S.C. Section 262 et seq., cGMPs, any applicable
      regulations promulgated by the EMEA, and any applicable regulations
      promulgated by Koseisho, as the same may be amended from time to time.

1.47  "Released Bulk Drug Substance" shall mean, with respect to a particular
      Site and a particular Calendar Year, Bulk Drug Substance that is, or is
      expected to be, released at such Site during such Calendar Year, including
      (a) any such Bulk Drug Substance for which manufacturing was commenced and
      completed and which was released during such Calendar Year, and (b) any
      such Bulk Drug Substance released during such Calendar Year that was Work
      In Process at the end of the prior Calendar Year.

1.48  "RI Capacity" shall mean the volume of Bulk Drug Substance that the
      Parties reasonably expect to be manufactured from the combined capacity of
      the Phase A Capacity and the Phase B Additional Capacity in a Calendar
      Year.

1.49  "RI Site" shall mean the portion of the biopharmaceutical manufacturing
      facility in West Greenwich, Rhode Island, currently owned by Greenwich,
      within which the RI Capacity is or will be manufactured. The RI Site shall
      not include such manufacturing facility with respect to its manufacture of
      Excluded Supply or products other than the Product.

1.50  "Safety Agreement" means the Memorandum of Understanding between Immunex
      Drug Safety Surveillance and Wyeth-Ayerst for the Identification,
      Collection, Evaluation and Regulatory Reporting of Adverse Events and
      Product Quality and for


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      the Provision of Medical Information for Enbrel(R) (etanercept), effective
      as of December 13, 2000, as the same may be amended from time to time.

1.51  "Site" shall mean the BIOS Site, the BIP Site, and/or the RI Site, as
      applicable.

1.52  "Specifications" shall mean a set of specifications for Bulk Drug
      Substance agreed upon by the Parties pursuant to the Quality Agreement.

1.53  "Subject Capacity" shall mean that manufacturing capacity subject to the
      Collaboration as further set forth in Section 2.2 below.

1.54  "Supply Shortage" shall mean the situation, as may be determined by the
      JSC from time to time, that in [*] of a Five-Year Plan approved by the
      JSC, the total quantity of Bulk Drug Substance that can be manufactured in
      the Subject Capacity is less than [*]. When a Supply Shortage is in
      effect, it shall be deemed to be in effect for the [*].

1.55  "T1 Process" shall mean the Immunex proprietary Manufacturing Process used
      by BIP as of the Effective Date to manufacture Bulk Drug Substance.

1.56  "T2 Process" shall mean the Immunex proprietary process for manufacturing
      Bulk Drug Substance, which process is currently the subject of the T2
      Development Agreement: TNFR:FC Process (Phase I), dated January 1, 1999,
      among Immunex, AHPC, and BIP, as the same may be amended from time to
      time.

1.57  "Territory" shall mean the Immunex Territory or the Wyeth Territory, as
      applicable, and "Territories" shall mean both the Immunex Territory and
      the Wyeth Territory, collectively.

1.58  "Third Party" shall mean any party other than Immunex, Wyeth, BIP, and
      their respective Affiliates.

1.59  "Total BIOS Facility Capacity" shall mean the BIOS Capacity plus the
      volume of Excluded Supply that can be produced in the biopharmaceutical
      manufacturing facility to be built at the Wyeth BioPharma campus at Grange
      Castle International Business Park, Clondalkin, Dublin 22, Ireland.

1.60  "Type" shall mean Bulk Drug Substance produced by a specified
      Manufacturing Process meeting a defined Specification approved by Immunex
      and Wyeth pursuant to the provisions of the Quality Agreement.

1.61  "Work in Process" shall mean Bulk Drug Substance for which manufacturing
      has commenced in a Calendar Year but which has not yet been released by
      the end of such Calendar Year.

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1.62 "Wyeth Territory" shall mean all the countries in the world other than
those within the Immunex Territory.

Each of the following definitions are found in the body of this Agreement as
indicated:

                                                                    Section
                                                                    -------
"Additional Term"                                                   14.1
"Adjusted Standard Product Price"                                   9.1(b)(iv)
"Base Allocation"                                                   5.2(a)
"Clinical Development Requirements"                                 5.2(b)
"Cost of Goods"                                                     2.2(d)
"Delivery Dates"                                                    8.2
"Detailed Forecast Schedule"                                        8.2
"Firm Order"                                                        8.2
"Five-Year Capacity Projection"                                     4.2(b)
"Five-Year Plan"                                                    4.2(c)
"Five-Year Requirement Schedule"                                    4.2(a)
"Force Majeure Event"                                               16.1
"Greater Volume Party"                                              2.2(d)(i)
"Immunex License Agreements"                                        10.3
"Indemnitor"                                                        13.3
"Indemnitee"                                                        13.3
"Initial Term"                                                      14.1
"JSC"                                                               3.1
"Kg"                                                                5.2(a)
"Liabilities"                                                       13.1
"Lower Volume Party"                                                2.2(d)(i)
"Net Sales"                                                         2.2(d)
"Product Development Steering Committee"                            5.2(b)
"Product Gross Profits"                                             2.2(d)
"Production Plan"                                                   4.2(c)(i)
"Publication"                                                       15.4
"Reasonable Steps"                                                  15.1
"RI Approval"                                                       4.1
"Royalities"                                                        2.2(d)
"Standard Product Price"                                            9.1(a)
"Sublicense Agreements"                                             10.3
"Supply Plan"                                                       4.2(c)(ii)
"Technology Transfer and License Agreement"                         7.3
"Term"                                                              14.1
"Territory Shortage"                                                2.2(d)


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                 Article 2. Scope of Agreement; Subject Capacity

2.1   Scope of Agreement.

      The purpose of the Collaboration is for the Parties to allocate and manage
      in a collaborative manner the manufacture and supply of Product deriving
      from the Subject Capacity.

2.2   Subject Capacity.

      (a)   Included Capacities. The Subject Capacity subject to the
            Collaboration shall be composed of the following:

            (i)   the BIP Capacity;

            (ii)  the RI Capacity; and

            (iii) the BIOS Capacity.

      (b)   Excluded Supply. Each Party shall be free to manufacture quantities
            of Product in addition to those included in the Subject Capacity, or
            to contract with a Third Party to manufacture at such Third Party's
            facilities such additional Product, for use by such Party within its
            Territory. All such additional quantities of Product Supply in
            excess of those included in the Subject Capacity, whether
            manufactured by or for a Party, shall be considered Excluded Supply
            that is not included within the Subject Capacity and, except as
            expressly set forth herein, shall not be subject to this Agreement.
            Without limiting the generality of the foregoing, (i) Immunex may,
            in its discretion, manufacture additional Product in the Phase B
            Facility or elsewhere at the RI Site, which additional Product shall
            be considered Excluded Supply, and (ii) Wyeth may, in its
            discretion, manufacture additional Product at the BIOS Site in
            excess of that included in the BIOS Capacity, which additional
            Product shall be considered Excluded Supply.

      (c)   [*]

      (d)   Equivalency of Capacities. Until [*], all supply within the Subject
            Capacity shall be allocated as set forth in this Agreement and
            purchased by the Parties for the prices set forth in Article 9
            (except as set forth in Section 2.2(c)), without regard for whether
            the bioreactor working volume available from the RI Site is
            equivalent to the bioreactor working volume available from the BIOS
            Site. If, at any time after [*], the RI Site and the BIOS Site have
            and continue to have substantially equivalent bioreactor working
            volumes within the Subject Capacity, all supply within the Subject
            Capacity shall be allocated as set forth in this Agreement and
            purchased by the Parties for the prices set forth in Article 9
            (except as set forth in Section 2.2(c)). Notwithstanding anything to
            the contrary in this Agreement, if, at any time after [*], the RI
            Site

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            and the BIOS Site do not have and continue not to have substantially
            equivalent bioreactor working volumes within the Subject Capacity,
            all supply within the Subject Capacity shall be allocated as set
            forth in this Agreement and purchased by the Parties at the
            following prices:

            (i)   Supply from Equivalent Bioreactor Working Volumes. All supply
                  from an equivalent bioreactor working volume within the
                  Subject Capacity from the RI Site or the BIOS Site, as
                  applicable, shall be purchased by the Parties for the prices
                  set forth in Article 9 (except as set forth in Section
                  2.2(c)). If a Party (the "Lower Volume Party") has a lower
                  total bioreactor working volume in the Subject Capacity than
                  the total bioreactor working volume of the other Party (the
                  "Greater Volume Party") in the Subject Capacity with respect
                  to all or a portion of a particular Calendar Year after [*],
                  the supply from the Greater Volume Party to the Lower Volume
                  Party priced in accordance with Article 9 (except as set forth
                  in Section 2.2(c)) for such portion of such Calendar Year
                  shall equal [*].

            (ii)  Supply from Additional Bioreactor Working Volumes. Quantities
                  of Bulk Drug Substance allocated to the Lesser Volume Party in
                  the applicable Five-Year Plan in excess of the quantities
                  supplied to the Lower Volume Party from its own Site and the
                  BIP Site and quantities purchased pursuant to subsection (i)
                  above shall be purchased by the Lesser Volume Party from the
                  Greater Volume Party, and shall be priced as follows:

                  (A)   Supply Shortage and Territory Shortage. If both a Supply
                        Shortage and a Territory Shortage are in effect with
                        respect to all or a portion of a particular Calendar
                        Year after [*], then such Bulk Drug Substance purchased
                        by the Lesser Volume Party shall be priced as follows
                        for that portion of such Calendar Year in which such
                        Supply Shortage and Territory Shortage are in effect:

                        (1)   If Wyeth is the Lesser Volume Party, then Wyeth
                              shall pay Immunex for such Bulk Drug Substance the
                              sum of: (a) the Standard Product Price determined
                              as set forth in Section 9.1; and (b) the [*].

                        (2)   If Immunex is the Lesser Volume Party, then
                              Immunex shall pay Wyeth for such Bulk Drug
                              Substance the sum of: (a) the Standard Product
                              Price determined as set forth in Section 9.1; and
                              (b) the [*].

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                                       12



                  (B)   Absence of Supply Shortage and/or Territory Shortage. If
                        either a Supply Shortage or a Territory Shortage is not
                        in effect, or if neither a Supply Shortage nor a
                        Territory Shortage is in effect, then such Bulk Drug
                        Substance purchased by the Lesser Volume Party shall be
                        priced as follows:

                        (1)   the Fully Absorbed Manufacturing Cost allocated to
                              the manufacture of such Bulk Drug Substance; plus

                        (2)   [*].

            As used in this Section 2.2(d), "Territory Shortage" shall mean the
            situation in which the [*]. As used in this Section 2.2(d), "Product
            Gross Profits" shall mean Net Sales of Product Supply Units, less
            the sum of Cost of Goods and Royalties. As used in this Section
            2.2(d), "Cost of Goods" shall mean, with respect to Product Supply
            Units, the total cost of finished goods, including, but not limited
            to, the Bulk Drug Substance at the Standard Product Price, other
            bulk materials, fill and finish, quality control, labeling,
            packaging, and shipping to a Party or its agent, and storage. As
            used in this Section 2.2(d), "Net Sales" shall mean the gross
            invoice price of Product Supply Units sold in a Party's Territory by
            a Party, its Affiliates, sublicensees, distributors, or other
            designees to a Third Party after deducting, if not already deducted
            in the amount invoiced or not otherwise accounted for in Cost of
            Goods: (a) the standard inventory cost (actual acquisition cost) of
            devices used for dispensing or administering such Product Supply
            Units and that accompany such Product Supply Units as they are sold;
            (b) then normal or customary trade, cash, and/or quantity discounts;
            (c) returns, allowances, free goods, rebates, and chargebacks; (d)
            retroactive price reductions applicable to sales of such Product
            Supply Units; (e) fees paid to distributors, selling agents
            (excluding any sales representatives of a Party or any of its
            Affiliates), group purchasing organizations, or managed care
            entities; (f) sales taxes, excise taxes, tariffs, and duties; and
            (g) [*] of the amount invoiced to cover bad debt, freight, or other
            transportation charges, insurance charges, additional special
            packaging, and other governmental charges. As used in this Section
            2.2(d), "Royalties" shall mean all running royalties paid to Third
            Parties or to the other Party pursuant to Sublicense Agreements
            under patent or technology licenses that are necessary or desirable
            in order to manufacture, import, use, sell, or distribute Product,
            provided that such royalties for purposes of the calculation of
            Product Gross Profits shall be capped at [*] of Net Sales, and any
            royalties above such amount shall be for the account of the Party
            that sold such Product.

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                                       13



                              Article 3. Governance

3.1   Joint Steering Committee.

      The Parties hereby establish a Joint Steering Committee (the "JSC") to
      manage the Collaboration. Each Party shall designate two (2) senior
      executives to serve on the JSC on the basis of their expertise in
      pharmaceutical manufacturing and supply management. The initial members of
      the JSC are listed on Exhibit B attached hereto. A Party shall be free to
      change either or both of its designated representatives upon reasonable
      written notice to the other Party. The Parties shall be free to increase
      the number of their respective representatives upon mutual agreement of
      the Parties in writing. The JSC shall appoint a chairperson from among its
      members, provided that the chairperson shall alternate between the Immunex
      members and the Wyeth members on an annual basis.

3.2   Role of JSC.

      The JSC shall be responsible for general management of the Collaboration.
      Its responsibilities shall include, without limitation, the following:

      (a)   Reviewing and approving the Five-Year Requirement Schedules, as
            further described in Section 4.2(a) below;

      (b)   Reviewing and approving the Five-Year Capacity Projections, as
            further described in Section 4.2(b) below;

      (c)   Establishing, maintaining, and updating the Five-Year Plan, as
            further described in Section 4.2(c) below;

      (d)   Overseeing the management of the Parties' joint relationship with
            BIP, with other contractors performing services related to the
            Product with regard to the Subject Capacity, and with suppliers of
            raw materials and other supplies for the Product with regard to the
            Subject Capacity;

      (e)   Serving as the initial forum for resolution of disputes between the
            Parties related to matters within the scope of the Collaboration, as
            set forth in Section 3.4 below;

      (f)   Establishing the quantities of safety inventories of Product to be
            maintained by the Parties, except as set forth in Section 5.5 below;

      (g)   Establishing the operating guidelines pursuant to which the Parties
            will allocate tasks to accomplish the effective functioning of the
            Collaboration;

      (h)   Creating a quality review board and such other subcommittees as the
            JSC deems necessary or appropriate for the effective functioning of
            the Collaboration;


                                       14



      (i)   Enforcing the responsibilities of and resolving disputes between the
            finance representatives designated by the Parties as set forth in
            Section 9.5(b);

      (j)   Making decisions regarding process improvements as set forth in
            Section 7.4(a)(i); and

      (k)   Performing the other tasks specifically set forth herein, as well as
            any other tasks that the JSC deems necessary or appropriate for the
            effective functioning of the Collaboration.

      Except as expressly set forth herein, or as determined by the JSC, the
      Parties shall be bound by the decisions made by the JSC hereunder. Each
      Party shall cause its members of the JSC to act in accordance with, and
      perform the functions of the JSC required by, this Agreement.

3.3   Meetings.

      The JSC shall meet as frequently as necessary to manage the Collaboration
      effectively, but at least semi-annually. The Chairperson shall send
      notices and agendas for all regular meetings to all JSC members. The
      location of regularly scheduled meetings shall alternate between the
      offices of the Parties. Meetings may be held telephonically, by video
      conference, or by any other media agreed to by the JSC. Members of the JSC
      shall have the right to participate in and vote at meetings by telephone
      or proxy. Each Party shall have one (1) vote on all matters within the
      jurisdiction of the JSC. The Party hosting any meeting shall appoint a
      person to record the minutes of the meeting; such minutes shall be
      circulated to the Parties promptly following the meeting for review,
      comment, ratification, and distribution. Each Party shall bear its own
      travel and related costs incurred in participation in the JSC. The JSC may
      invite additional participants from relevant functions to attend JSC
      meetings when appropriate for the issues being addressed at the meeting.

3.4   Dispute Resolution.

      The JSC shall endeavor to reach a consensus on all matters within its
      purview. In the event that the JSC cannot reach consensus on a matter, or
      in the event that a disputed matter between the Parties is referred to the
      JSC, the JSC shall strive to resolve such matter within a period of ten
      (10) calendar days after the disputed matter is identified or referred to
      the JSC in writing for resolution. If the JSC cannot reach a resolution
      within the applicable time period (or earlier at the election of either
      Party), the matter shall be referred to resolution in accordance with
      Article 18 below.

                     Article 4. Allocation; Five-Year Plans

4.1   Short-Term Allocation.

      Until either the FDA or EMEA has approved manufacture of Bulk Drug
      Substance at the RI Site ("RI Approval"), the supply of Bulk Drug
      Substance shall be allocated as follows:


                                       15



      (a)   Product Manufactured at the BIP Site. Until RI Approval, Wyeth shall
            have the right to receive such quantities of Bulk Drug Substance as
            set forth in the Short-Term Allocation Agreement, pursuant to the
            terms of the Short-Term Allocation Agreement, and any written
            agreements involving both of the Parties relating to importation of
            Product Supply Units from Immunex's customers into the Wyeth
            Territory.

      (b)   Clinical Trial Material Manufactured at RI Site. In the event that
            Bulk Drug Substance manufactured at the RI Site, prior to RI
            Approval, is used in Product Supply for the Parties' clinical
            trials, and such use permits additional Product manufactured at the
            BIP Site to be allocated for use and used for the commercial market,
            the amount of additional Product obtained for the commercial market
            because of such substitution shall be [*]. The JSC shall determine
            the amount of such Product, if any, subject to such allocation.

4.2   Five-Year Planning.

      (a)   Five-Year Requirement Schedules. On [*] each Party shall provide the
            JSC with a written five-year requirement schedule (a "Five-Year
            Requirement Schedule") for the period beginning [*] of its projected
            requirements for Bulk Drug Substance from the Subject Capacity for
            its Territory, net of Bulk Drug Substance reasonably expected to be
            satisfied from Excluded Supply, according to Type, divided into
            monthly increments for the first Calendar Year and divided into
            yearly increments for the remaining four (4) Calendar Years. By each
            [*] thereafter, each Party shall submit to the JSC an updated
            Five-Year Requirement Schedule for the period beginning [*] of the
            following Calendar Year. Within thirty (30) days after each such
            submission, the JSC shall review the Five-Year Requirement
            Schedules, and either, at its discretion, approve the Five-Year
            Requirement Schedules, or request additional information from the
            Parties as needed to use the Five-Year Requirement Schedules to
            establish the Five-Year Plan. At the JSC's discretion and request,
            the Parties shall update their Five-Year Requirement Schedules by
            each [*] thereafter. Each Five-Year Requirement Schedule provided
            hereunder shall include, for each Calendar Year included therein:

            (i)   total Bulk Drug Substance requirements from the Subject
                  Capacity, separated according to Type, on a region-by-region
                  basis;

            (ii)  Bulk Drug Substance requirements by indication on a
                  Territory-wide basis, separated according to Type;

            (iii) a schedule of expected dates of submission and approval by
                  Regulatory Authorities, on a country-by-country basis within
                  such Party's Territory, of initial marketing applications for
                  the Product, and

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                                       16



                  supplemental submissions for additional indications to be
                  added to the Product labeling;

            (iv)  information concerning sales of Product during the preceding
                  six (6) months on a Territory-wide basis; and

            (v)   any other information reasonably requested by the JSC.

      (b)   Five-Year Capacity Projections. On [*], each Party shall provide the
            JSC with a written five-year capacity projection (a "Five-Year
            Capacity Projection") beginning [*] for the Subject Capacity from
            each of its Sites according to Type, divided into monthly increments
            for the first Calendar Year of a Capacity Projection and divided
            into yearly increments for the remaining four Calendar Years of a
            Capacity Projection. Immunex shall submit the Five-Year Capacity
            Projection for the BIP Site and the RI Site, and Wyeth shall submit
            the Five-Year Capacity Projection for the BIOS Site. By each [*]
            thereafter, each Party shall submit to the JSC an updated Five-Year
            Capacity Projection for the period beginning [*] of the following
            Calendar Year. Within thirty (30) days after each such submission,
            the JSC shall review the Five-Year Capacity Projections, and either,
            at its discretion, approve the Five-Year Capacity Projections, or
            request additional information from the Parties as needed to use the
            Five-Year Capacity Projections to establish the Five-Year Plan. At
            the JSC's discretion and request, the Parties shall update their
            Five-Year Capacity Projections by each [*] thereafter. Each
            Five-Year Capacity Projection provided hereunder shall include, for
            each year included therein:

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                                       17



            (i)   the total quantity of Bulk Drug Substance that can reasonably
                  be expected to be produced and released at the Site within
                  bioreactors included in the Subject Capacity, separated
                  according to Type;

            (ii)  the projected Standard Product Price for Released Bulk Drug
                  Substance at the Site within bioreactors included in the
                  Subject Capacity, according to Type, which price shall be
                  non-binding on the Parties;

            (iii) a schedule of expected dates of submissions to and approval by
                  Regulatory Authorities, of Regulatory Filings regarding
                  additional Sites to manufacture the Product and process and
                  other changes, on a regional or country-by-country basis;

            (iv)  inventory of Product on hand from the Subject Capacity,
                  separated according to Type, on a region-by-region basis, as
                  of one month before the date of submission of the such
                  Five-Year Capacity Projection; and

            (v)   any other information reasonably requested by the JSC.

      (c)   Five-Year Plan. By [*], and by each [*] thereafter during the Term,
            the JSC shall establish the "Five-Year Plan" for the upcoming five
            (5) Calendar Years. The JSC shall determine, in its discretion,
            whether it is necessary to adjust each such Five-Year Plan after
            receiving submissions from the Parties by each [*] and, shall make
            any such necessary adjustments. The Five-Year Plan shall include,
            for each Calendar Year included therein, a Production Plan and a
            Supply Plan, as further described below.

            (i)   Production Plan. Each Five-Year Plan shall indicate the
                  quantity of Bulk Drug Substance separated according to Type
                  reasonably expected to be manufactured and released at each
                  specific Site within the Subject Capacity (the "Production
                  Plan"). The Production Plan shall be established on a Calendar
                  Year basis within the applicable Five-Year Plan.

            (ii)  Supply Plan. Each Five-Year Plan shall indicate: (A) the
                  quantity of Bulk Drug Substance reasonably expected to be
                  supplied to each of the Territories separated according to
                  Type; and (B) the quantity of Bulk Drug Substance reasonably
                  expected to be manufactured at each specific Site separated
                  according to Type to be supplied to each of the Parties for
                  their respective Territories (the "Supply Plan"). The Supply
                  Plan shall be established on a monthly basis for the first
                  Calendar Year included in the Five-Year Plan, and on a
                  Calendar Year basis for the remaining four (4) Calendar Years
                  within the Five-Year Plan, on a Territory-wide basis.

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            (iii) Reconciliation. In establishing a Five-Year Plan, the JSC
                  shall review the Bulk Drug Substance that was actually
                  distributed to the Parties from the Subject Capacity during
                  the preceding Calendar Year to determine whether the capacity
                  actually received by each Party during the preceding Calendar
                  Year equaled the capacity to which each Party was entitled
                  pursuant to this Agreement. If one Party did not receive the
                  capacity from the Subject Capacity to which such Party was
                  entitled under the Five-Year Plan for such preceding Calendar
                  Year, the JSC shall make any appropriate adjustments to the
                  Five-Year Plan that it is establishing to account for such
                  discrepancy.

4.3   General Principles of Allocation.

      In the absence of a Supply Shortage or a Production Surplus, the JSC shall
      be guided by the following principles in establishing the Five-Year Plans.

      (a)   The JSC shall use its best efforts to prevent any out-of-stock
            situation in any Major Market, including but not limited to
            resolving any short supply issues for each Type. The JSC shall use
            its commercially reasonable efforts to prevent any out-of-stock
            situation in any non-Major Market, including but not limited to
            resolving any short supply issues for each Type.

      (b)   [*]

      (c)   The JSC shall use its best efforts to prevent out-dating of Bulk
            Drug Substance.

      (d)   The JSC shall use its best efforts to minimize costs to the extent
            they impact the Blended Price.

      (e)   The JSC shall use its best efforts to allocate supply such that each
            Party receives the Type of Bulk Drug Substance that such Party
            requires.

4.4   Binding Portion of Five-Year Plan.

      The [*] of each Five-Year Plan shall be binding on the Parties.
      Notwithstanding anything herein to the contrary, the initial Five-Year
      Plan shall not become effective nor bind the Parties until RI Approval,
      and prior to that time, the supply of Bulk Drug Substance shall be
      allocated according to Section 4.1 above. The JSC shall not change a
      binding portion of a Five-Year Plan. The Parties shall be obligated to
      utilize the capacity and to purchase the quantities of Bulk Drug Substance
      set forth in the binding portion of the Five-Year Plan. The remaining
      portions of a Five-Year Plan shall not be binding on the Parties, but the
      Parties shall use such Five-Year Plan for joint planning purposes.

4.5   Specific Product Purchases.

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                                       19



      The Parties shall purchase Product from each other in the quantities
      specified in the Five-Year Plan, according to the terms set forth in this
      Agreement.

      (a)   BIP Site. Under the Enbrel Supply Agreement, the Parties have the
            option to receive Bulk Drug Substance Lots manufactured by BIP; the
            remainder of the Bulk Drug Substance manufactured by BIP is
            converted by BIP to Drug Product and/or Finished Product that is
            sold to the Parties thereunder.

            (i)   In the event that a Party desires to receive Bulk Drug
                  Substance from BIP, such Party shall so specify in its
                  Five-Year Requirement Schedule submitted to the JSC. The JSC
                  shall approve any such request that complies with the Enbrel
                  Supply Agreement or, if necessary, shall limit the quantities
                  of Bulk Drug Substance requested by one or both Parties to
                  ensure such compliance. Any Party who requests Bulk Drug
                  Substance from BIP shall pay BIP the cost therefor under the
                  Enbrel Supply Agreement and shall bear the cost of and the
                  risk of loss during the fill-finish, labeling, packaging, and
                  other services necessary to convert such Bulk Drug Substance
                  to Product Supply.

            (ii)  In the event that a Party requests Drug Product or Finished
                  Product from BIP, such Party shall pay BIP the cost therefor
                  under the Enbrel Supply Agreement and shall bear the cost of
                  the labeling, packaging, and other services necessary to
                  convert such Product to Product Supply.

      (b)   RI Site.

            (i)   For the quantities of Bulk Drug Substance that Wyeth receives
                  from the RI Site, Wyeth shall purchase the Bulk Drug Substance
                  form of the Product and shall pay Immunex therefor in
                  accordance with Article 9 below. Wyeth may enter into an
                  agreement with Immunex or a Third Party pursuant to which
                  Immunex or a Third Party would perform certain fill-finishing,
                  labeling, packaging, and other services necessary to convert
                  such Bulk Drug Substance to Product Supply on terms and
                  conditions mutually agreed upon in writing by Wyeth and
                  Immunex, or a Third Party, as applicable.

            (ii)  When (A) more than [*] liter nominal volume bioreactors are
                  used to produce Bulk Drug Substance in the Phase B Facility in
                  a given Calendar Year, or, (B) if the Phase A Capacity is
                  moved to the Phase B Facility, more than [*] liter nominal
                  volume bioreactors are used to produce Bulk Drug Substance in
                  the Phase B Facility in a given Calendar Year, the quantity of
                  Bulk Drug Substance subject to allocation and purchase in
                  accordance with the applicable Five-Year Plan shall equal the
                  [*].

      (c)   BIOS Site.

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                                       20



            (i)   For the quantities of Bulk Drug Substance that Immunex
                  receives from the BIOS Site, Immunex shall purchase the Bulk
                  Drug Substance form of the Product and shall pay Wyeth
                  therefor in accordance with Article 9 below. Immunex may enter
                  into an agreement with Wyeth or a Third Party pursuant to
                  which Wyeth or a Third Party would perform certain
                  fill-finishing, labeling, packaging, and other services
                  necessary to convert such Bulk Drug Substance to Product
                  Supply on terms and conditions mutually agreed upon in writing
                  by Immunex and Wyeth, or a Third Party, as applicable.

            (ii)  If a greater number of bioreactors than those included in the
                  BIOS Capacity are used to produce Bulk Drug Substance in the
                  Total BIOS Facility Capacity in a given Calendar Year, the
                  quantity of Bulk Drug Substance subject to allocation and
                  purchase in accordance with the applicable Five-Year Plan
                  shall equal the [*].

              Article 5. Product Allocation During Supply Shortage

5.1   Scope.

      Except as set forth in Section 5.6 below, in the event that there is a
      Supply Shortage, the JSC shall allocate the total quantity of Bulk Drug
      Substance manufactured in the Subject Capacity as set forth in this
      Article 5, for each of the Calendar Years for which the Supply Shortage is
      in effect pursuant to Section 1.54 above.

5.2   Allocation of Combined BIP Capacity and Phase A Capacity.

      The total volume of Bulk Drug Substance available from the combined BIP
      Capacity and Phase A Capacity shall be allocated as follows, in the
      following priority:

      (a)   Base Allocation. The first [*] Kilograms ("Kg ") of Bulk Drug
            Substance available from the combined BIP Capacity and Phase A
            Capacity (the "Base Allocation") shall be allocated as follows:

            (i)   Immunex shall receive [*] Kg; and

            (ii)  Wyeth shall receive [*] Kg.

            In the event that fewer than [*] Kg of Bulk Drug Substance are
            available from the combined BIP Capacity and Phase A Capacity, then
            Immunex shall receive [*] and Wyeth shall receive [*] of the
            available quantities.

      (b)   Clinical Development Requirements. Additional volumes of Bulk Drug
            Substance above the Base Allocation that are available from the
            combined

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                                       21



            BIP Capacity and Phase A Capacity, if any, shall be used to satisfy
            any ongoing clinical trials being conducted by the Parties, as well
            as any new clinical trials agreed upon by the "Product Development
            Steering Committee" under the TNFR Agreement (as that term is
            defined therein) (collectively, the "Clinical Development
            Requirements"). [*] To the extent that the Parties agree that excess
            quantities of Bulk Drug Substance from the quantities allocated to
            the Clinical Development Requirements are available from time to
            time, such quantities shall be allocated as follows:

            (i)   If the Base Allocation has not been satisfied as set forth in
                  Section 5.2(a) in the Calendar Years in which the Parties
                  agree that excess quantities are available, the excess
                  quantities shall be allocated as set forth in Section 5.2(a).

            (ii)  If the Base Allocation has already been satisfied as set forth
                  in Section 5.2(a) in the Calendar Years in which the Parties
                  agree that excess quantities are available, the excess
                  quantities shall be allocated as set forth in Section 5.2(c).

      (c)   Additional Quantities. Additional quantities of Bulk Drug Substance
            that are available from the combined BIP Capacity and Phase A
            Capacity, if any, above that necessary to satisfy the Base
            Allocation and the Clinical Development Requirements, shall be
            allocated as follows:

                                                           Immunex      Wyeth
            --------------------------------------------------------------------

            First [*] Kg or portion thereof                  [*]        [*]
            --------------------------------------------------------------------

            Next [*] Kg or portion thereof                   [*]        [*]
            --------------------------------------------------------------------

            Next [*] Kg or portion thereof                   [*]        [*]
            --------------------------------------------------------------------

            Next [*] Kg or portion thereof                   [*]        [*]
            --------------------------------------------------------------------

            All additional supplies from the combined
            BIP Capacity and Phase A Capacity                [*]        [*]
            --------------------------------------------------------------------

      (d)   Example. By way of example only, the following table demonstrates
            how the quantities of total Bulk Drug Substance available from the
            BIP and Phase A Capacity, as shown below, would be allocated during
            a Supply Shortage. (The numbers shown below have been rounded to the
            nearest 0.5 Kg.)

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                                       22



         ----------------------------------------------------------------------
                                                                   Clinical
          Total Supply from BIP                                   Development
          Capacity and from Phase A    Immunex       Wyeth       Requirements
          Capacity                        Kg           Kg             Kg
         ----------------------------------------------------------------------
                    [*]                  [*]          [*]             [*]
         ----------------------------------------------------------------------
                    [*]                  [*]          [*]             [*]
         ----------------------------------------------------------------------
                    [*]                  [*]          [*]             [*]
         ----------------------------------------------------------------------
                    [*]                  [*]          [*]             [*]
         ----------------------------------------------------------------------
                    [*]                  [*]          [*]             [*]
         ----------------------------------------------------------------------
                    [*]                  [*]          [*]             [*]
         ----------------------------------------------------------------------

5.3   Allocation of Phase B Additional Capacity.

      In the event of a Supply Shortage, the volume of Bulk Drug Substance
      available from the Phase B Additional Capacity shall be allocated [*] to
      Immunex and [*] to Wyeth.

5.4   Allocation of BIOS Capacity.

      In the event of a Supply Shortage, the volume of Bulk Drug Substance
      available from the BIOS Capacity shall be allocated [*] to Wyeth and [*]
      to Immunex.

5.5   Safety Stock.

      During any period of Supply Shortage, each Party shall be responsible for
      maintaining its own inventory of safety stock from among the quantities it
      is allocated pursuant to this Article 5.

5.6   Sale of Product between Parties.

      If there is a Supply Shortage and the allocation of Bulk Drug Substance
      according to this Article 5 provides a Party with excess supply above that
      required to meet such Party's supply needs, as determined in such Party's
      sole discretion, such Party shall have the right, but not the obligation,
      to sell additional Bulk Drug Substance to the other Party beyond that
      allocated to such other Party according to this Article 5; provided,
      however, that any such quantities of Bulk Drug Substance that derive from
      the Subject Capacity and are sold by one Party to the other Party shall be
      sold at a price that does not exceed the applicable Blended Price
      established for such Bulk Drug Substance during the Calendar Year in which
      the sale occurs.

5.7   Allocation According to Type.

      In establishing a Five-Year Plan, the JSC shall use its best efforts to
      allocate to a Party the Type of Bulk Drug Substance required by such
      Party. If the JSC is bound, according to this Article 5, to allocate a
      certain percentage of Bulk Drug Substance from one Site or a portion
      thereof to a Party, and such Site manufactures a particular Type of Bulk
      Drug Substance that is not required by such Party, the JSC shall
      substitute an equivalent quantity of Bulk Drug Substance from a different
      Site that produces a Type required by such Party, and shall make any
      necessary corresponding adjustments to maintain compliance with Article 5.

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                                       23



             Article 6. Product Allocation During Production Surplus

6.1   Allocation.

      In the event that there is a Production Surplus, the total quantity of
      Bulk Drug Substance that can be manufactured in the Subject Capacity shall
      be allocated as set forth below.

      (a)   BIP Obligations. [*].

      (b)   Additional Supply Needs. If there is additional demand for Product
            Supply beyond the quantities produced as a result of the allocation
            to the BIP Capacity under Section 6.1(a) above, then production
            shall be allocated among the RI Capacity and the BIOS Capacity
            according to the following formula.

            [*]

      (c)   Example. By way of example only, assume that the respective
            capacities of the Subject Capacities as follows:

            BIP Capacity:  [*]

            RI Capacity:   [*]

            BIOS Capacity: [*]

            Total: [*]

            Assume further that (i) the worldwide demand for Product Supply is
            [*] per year, and (ii) the Parties must purchase [*] from BIP to
            meet their minimum contractual obligation under the Enbrel Supply
            Agreement. Production shall be allocated as follows:

            BIP Capacity:  [*]

            RI Capacity:   [*]

            BIOS Capacity: [*]

                        Article 7. Manufacturing Strategy

7.1   Regulatory Approvals.

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                                       24



      The Parties shall cooperate in good faith and use all commercially
      reasonable efforts to obtain approval from the applicable Regulatory
      Authorities for each Site to manufacture Bulk Drug Substance for each of
      the Major Markets. Immunex shall be responsible for all Regulatory Filings
      for each Site to enable each Site to manufacture Bulk Drug Substance for
      countries within the Immunex Territory as deemed necessary by Immunex, and
      Wyeth shall be responsible for all Regulatory Filings for each Site to
      enable each Site to manufacture Bulk Drug Substance for countries within
      the Wyeth Territory as deemed necessary by Wyeth. Each Party shall offer
      its reasonable assistance to the other Party in preparing any such
      Regulatory Filings. Each Party shall reimburse the other for [*] incurred
      by such other Party in connection with the performance of such other
      Party's obligations under the preceding sentence. The Parties shall
      attempt to obtain such approvals as quickly as practicable. The Parties
      shall attempt to qualify the Subject Capacity in those Major Markets where
      the qualification is reasonably likely to be obtained the earliest, as
      agreed upon by Immunex and Wyeth; provided, however, that the Parties
      shall simultaneously use all commercially reasonable efforts to qualify
      the Subject Capacity for manufacturing Bulk Drug Substance for use in the
      United States, the European Union, and Japan.

7.2   Raw Materials and Supplies.

      (a)   General. Each Site shall be responsible for purchasing the raw
            materials and other supplies necessary to manufacture Bulk Drug
            Substance, Drug Product, and/or Finished Product, as applicable, at
            its location. The Parties shall, however, cooperate with regard to
            purchasing from specific suppliers, particularly sole source
            suppliers, and shall, when reasonably practicable, enter into joint
            contracts or other purchasing arrangements with suppliers, with the
            objective of obtaining more favorable pricing and other terms than
            if such Party was purchasing alone. In addition, the Parties shall
            cooperate in working with BIP in purchasing from such suppliers. The
            JSC shall direct the Parties' management of the relationship with
            common suppliers, and in the event that entering into a joint
            purchasing arrangement with a sole source supplier is not reasonably
            practicable, then the JSC shall oversee and direct each Party's
            individual contractual relationship with such supplier. Section 5.3
            of the Quality Agreement addresses quality issues related to raw
            materials.

      (b)   Shortage. [*]

7.3   Technology Transfer and License.

      Immunex and Wyeth shall enter into a technology transfer and license
      agreement simultaneously herewith setting forth the terms and conditions
      simultaneously herewith pursuant to which transfer of the technology for
      the Manufacturing Process to Wyeth will occur (the "Technology Transfer
      and License Agreement").

7.4   Changes to the Product.

      (a)   Process Changes.

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            (i)   The Parties shall collaborate with regard to any process
                  improvement efforts for the Manufacturing Process. The JSC
                  shall make all decisions regarding joint investments for
                  development work for process improvements, allocating costs of
                  such development work if such costs are to be allocated other
                  than as set forth in Section 3.05 of the TNFR Agreement,
                  whether to implement any such jointly funded process
                  improvements into the Manufacturing Process, the timing of
                  such implementation at the various Sites, [*]. The JSC shall
                  consider the requirements of all countries within the
                  Territories in determining whether to jointly fund development
                  work for process improvements.

            (ii)  The Parties, through the JSC, shall cooperate in good faith to
                  help ensure that, as improvements to the Manufacturing Process
                  are implemented, [*].

            (iii) Implementation of process changes is also addressed in Article
                  10 of the Quality Agreement.

      (b)   Other Changes. The Parties' technical, production scheduling,
            regulatory and other appropriate personnel shall work together to
            coordinate other changes to the Product, including but not limited
            to formulation changes, presentation changes [*], and assay changes.
            The JSC shall provide general direction to the Parties with respect
            to the implementation and timing of such changes, with the objective
            of ensuring that (i) Product incorporating a particular change is
            available from one or more of the Sites to support the Major Markets
            where such change is approved, (ii) to the extent commercially
            practicable, Product not incorporating a particular change is
            available from one or more of the Sites to support the Major Markets
            where such change is not approved, and (iii) Product inventory is
            managed appropriately to accomplish (i) and (ii) above and to
            implement changes as efficiently as possible. Implementation of such
            changes is also addressed in Article 10 of the Quality Agreement.

7.5   Manufacturing Strategy.

      The Parties shall use commercially reasonable efforts to manufacture Bulk
      Drug Substance to meet [*] Regulatory Requirements in the Major Markets.
      [*] Any disputes regarding the foregoing shall be resolved as set forth in
      the Quality Agreement.

7.6   Quality Agreement.

      Immunex and Wyeth shall comply with the provisions of the Quality
      Agreement. To the extent possible, the provisions of the Quality Agreement
      shall be interpreted consistently with the provisions of this Agreement.

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       Article 8. Supply of Bulk Drug Substance Between Immunex and Wyeth

8.1   Supply of Bulk Drug Substance.

      Immunex shall supply Bulk Drug Substance to Wyeth from the RI Site, and
      Wyeth shall supply Bulk Drug Substance to Immunex from the BIOS Site,
      subject to the terms and conditions of this Agreement and the Quality
      Agreement. All Bulk Drug Substance supplied by Immunex or Wyeth hereunder
      shall conform to the provisions of the Quality Agreement, including,
      without limitation, the Specifications for such Bulk Drug Substance set
      forth in the Quality Agreement.

8.2   Forecasts.

      On the [*] after each Five-Year Plan is established pursuant to Section
      4.2(c), each of Immunex and Wyeth shall provide to the other a One Year
      "Detailed Forecast Schedule" for the amount of [*] of Bulk Drug Substance,
      separated according to Type, to be delivered on delivery dates (the
      "Delivery Dates"), by [*], for the following Calendar Year. The Detailed
      Forecast Schedule shall be considered a "Firm Order" in accordance with
      the binding portion of the Five Year Plan.

8.3   Delivery.

      (a)   Delivery Terms. Wyeth and Immunex shall each arrange for shipment of
            the Bulk Drug Substance to the other Party and/or its respective
            designee at the purchasing Party's expense, F.O.B. the purchasing
            Party's designated carrier, and in accordance with the purchasing
            Party's instructions, including instructions as to designated
            carrier(s) to utilize. Title to, and risk of loss of, the Bulk Drug
            Substance shall remain with the supplying Party until delivery to
            the designated carrier specified by the purchasing Party, at which
            time the purchasing Party shall assume risk of loss of the Bulk Drug
            Substance.

      (b)   Filling Firm Orders. The supplying Party shall fulfill each Firm
            Order submitted pursuant to Section 8.2 above, for such quantities
            of Bulk Drug Substance specified in such Firm Order for each
            purchasing Party, on or before the specified Delivery Date
            applicable thereto and in accordance with any instructions of the
            purchasing Party; provided, however, that the Parties shall deliver
            Bulk Drug Substance in whole Bulk Drug Substance Lots.
            Notwithstanding anything herein to the contrary, if supply from a
            Bulk Drug Substance Lot is lower than expected, the deficiency shall
            not constitute a breach of an obligation to fulfill a Firm Order. If
            a Supply Shortage is in effect when such deficiency occurs, Immunex
            and Wyeth shall receive a reduced quantity of Bulk Drug Substance to
            accommodate such deficiency proportionately based on the allocation
            set forth in the applicable Five-Year Plan on a monthly basis. If a
            Supply Shortage is not in effect when such deficiency occurs, the
            deficient quantity shall be placed on backorder.

      (c)   Delivery Schedule. The Parties will cooperate to maintain a
            non-binding rolling [*] delivery schedule. Such schedule shall be
            updated at least monthly

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            and will specify the quantity of and delivery dates for Bulk Drug
            Substance to be delivered in the next [*].

      (d)   Compliance. Each Party shall comply with all applicable laws and
            regulations regarding the transportation and shipment of the Bulk
            Drug Substance for all deliveries made by such Party pursuant to
            this Agreement.

8.4   Division of Orders for and Delivery of Allocated Supply.

      The Parties will use commercially reasonable efforts to deliver Product in
      accordance with the binding forecast (as described in Section 4.4) in each
      month of the Detailed Forecast Schedule, unless otherwise agreed by the
      Parties in writing.

8.5   Product Warranties.

      (a)   Warranties by Wyeth. Wyeth hereby warrants to Immunex that the Bulk
            Drug Substance that Immunex purchases from Wyeth under this
            Agreement, at the time of sale and shipment by Wyeth: (i) shall
            conform to the provisions of the Quality Agreement, including,
            without limitation, the applicable Specifications for such Bulk Drug
            Substance; (ii) shall have been manufactured in compliance with all
            Regulatory Requirements in the United States; and (iii) shall be
            transferred free and clear of any liens or encumbrances of any kind
            related to Wyeth's activities hereunder.

      (b)   Warranties by Immunex. Immunex hereby warrants to Wyeth that the
            Bulk Drug Substance that Wyeth purchases from Immunex under this
            Agreement, at the time of sale and shipment by Immunex: (i) shall
            conform to the provisions of the Quality Agreement, including,
            without limitation, the applicable Specifications for such Bulk Drug
            Substance; (ii) shall have been manufactured in compliance with all
            Regulatory Requirements in the Major Markets; and (iii) shall be
            transferred free and clear of any liens or encumbrances of any kind
            related to Immunex's activities hereunder.

      (c)   Continuing Warranties. The warranties set forth in this Section
            8.5(a) and (b) shall be continuing warranties and shall be
            applicable to all of the Bulk Drug Substance delivered by Wyeth or
            Immunex to the other Party pursuant to this Agreement.

      (d)   Disclaimer. THE WARRANTIES SET FORTH IN SECTIONS 8.5(a) AND 8.5(b)
            ABOVE ARE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED,
            INCLUDING ANY WARRANTY OF MERCHANTABILITY AND ANY WARRANTY OF
            FITNESS FOR A PARTICULAR PURPOSE. EXCEPT FOR THE WARRANTIES
            EXPRESSED IN SECTIONS 8.5(a) AND 8.5(b) ABOVE, NEITHER PARTY MAKES
            ANY OTHER WARRANTY, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE
            PRODUCT.

8.6   Validation.

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      Product and process validation shall be governed by Article 11 of the
      Quality Agreement.

8.7   Claims.

      (a)   Notice of Claims. In the event that any of the Bulk Drug Substance
            supplied hereunder shall fail to conform with any warranty set forth
            in Section 8.5(a) or Section 8.5(b) hereof, the purchasing Party may
            reject the same by giving written notice thereof to the supplying
            Party within [*] days after shipment (or in the case of a latent
            defect, within [*] days after discovery of such latent defect, but
            in no case later than [*] after delivery to the designated carrier
            specified by the purchasing Party), which notice shall specify the
            manner in which such Bulk Drug Substance fails to conform to any
            warranty. In the alternative, rather than initially issuing a notice
            of rejection, the purchasing Party may give written notice to the
            supplying Party within the time period specified in this Section
            8.7(a) of a decision by the purchasing Party to investigate whether
            a potentially nonconforming shipment should be rejected, which
            investigation shall, unless otherwise agreed upon by the Parties, be
            completed within the time period set forth in this Section 8.7(a).

      (b)   No Supplier Liability. If it is determined by agreement of Immunex
            and Wyeth (or in the absence of such agreement, by a mutually
            acceptable qualified Third Party whose determination shall be
            binding on Immunex and Wyeth and whose fees shall be paid by the
            non-prevailing Party) that the nonconformity is due to damage to the
            Bulk Drug Substance caused by the purchasing Party or its agents
            subsequent to delivery of such Bulk Drug Substance by the supplying
            Party, the supplying Party shall have no liability to Purchaser with
            respect thereto.

      (c)   Supplier Liability; Replacement Product. If it is determined by
            agreement of Immunex and Wyeth (or in the absence of such agreement,
            by a mutually acceptable qualified Third Party whose determination
            shall be binding on Immunex and Wyeth and whose fees shall be paid
            by the non-prevailing Party) that the nonconformity is caused by the
            supplying Party, the supplying Party shall as soon as reasonably
            possible replace such nonconforming Bulk Drug Substance with
            conforming Bulk Drug Substance, at no additional cost to the
            purchasing Party, and the supplying Party shall pay the full cost of
            disposal or return of such Bulk Drug Substance to the supplying
            Party.

      (d)   Disposition of Nonconforming Product. In any case where a purchasing
            Party expects to make a claim against a supplying Party with respect
            to damaged or otherwise nonconforming Bulk Drug Substance, the
            purchasing Party shall not dispose of or allow to be disposed such
            Product without written authorization and instructions of the
            supplying Party either to dispose of or return to the supplying
            Party such Bulk Drug Substance. Upon written request by the
            purchasing Party, the supplying Party agrees promptly to give the
            purchasing Party such authorization and instructions within a
            reasonable period of time.

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8.8   Manufacturing Audits, Regulatory Matters.

      (a)   Manufacturing Audits. The Parties shall have the right to perform
            manufacturing audits as set forth in Sections 8.4 and 8.5 of the
            Quality Agreement.

      (b)   Records. Each Party shall maintain records relating to the
            production of the Product hereunder in accordance with Section 7.6
            of the Quality Agreement. Each Party agrees that, in response to any
            complaint or in the defense by the other Party of any litigation,
            hearing, regulatory proceeding or investigation relating to the
            Product, it shall use reasonable efforts to make available to the
            other Party during normal business hours and upon reasonable prior
            written notice, such Party's employees and records reasonably
            necessary to permit the effective response to, defense of, or
            investigation of such matters, subject to appropriate
            confidentiality protections. Each Party shall reimburse the other
            for [*] by such other Party in connection with the performance of
            such other Party's obligations under the preceding sentence.

      (c)   Notification to Other Party of Regulatory Correspondence. Within [*]
            business days after receiving or finalizing such document, each of
            Immunex and Wyeth shall promptly notify the other Party in writing
            of, and shall provide each other with copies of, any correspondence
            and other documentation received or prepared by such Party in
            connection with receipt of a regulatory letter, warning, or similar
            item, from any Regulatory Authority related to an inspection of the
            RI Site or the BIOS Site, as applicable, that could affect
            production of the Product; (ii) any recall, market withdrawal or
            correction of any lot of any Product provided by such Party to the
            other Party hereunder; and (iii) any comments by a Regulatory
            Authority concerning the Product requiring a response or action by
            Immunex or Wyeth.

8.9   Recalls.

      (a)   Immunex Territory. Each Party shall notify the other Party promptly
            (and, in any event, within [*] business days of receipt of written
            notice) if any Bulk Drug Substance, Finished Product, Drug Product,
            or Product Supply is alleged or proven to be the subject of a
            recall, market withdrawal or correction in any country in the
            Immunex Territory. Immunex and Wyeth shall cooperate in the handling
            and disposition of such recall, market withdrawal or correction in
            the Immunex Territory; provided, however, that in the event of
            disagreement as to any matters related to such recall, market
            withdrawal or correction, other than the determination of who shall
            bear the costs as set forth in the immediately following sentence,
            Immunex, after consultation with Wyeth, shall have final authority
            with respect to such matters in the Immunex Territory, which
            authority shall be exercised reasonably in and in good faith.
            Immunex shall bear the cost of all recalls, market withdrawals, or
            corrections of Bulk Drug Substance, Finished Product, Drug Product,
            or Product Supply in the Immunex Territory unless such recall,
            market withdrawal or correction shall have

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            been the result of any breach of Wyeth's covenants, representations,
            or warranties set forth in this Agreement or shall have been the
            result of Wyeth's grossly negligent breach of any of its obligations
            hereunder, in which case Wyeth shall, upon substantiation, bear the
            cost of such recall, market withdrawal, or correction. Immunex or
            its agent shall in all events be responsible for conducting any
            recalls, market withdrawals or corrections with respect to Bulk
            Substance, Finished Product, Drug Product, or Product Supply in the
            Immunex Territory.

      (b)   Wyeth Territory. Each Party shall notify the other Party promptly
            (and, in any event, within [*] business days of receipt of written
            notice) if any Bulk Drug Substance, Finished Product, Drug Product,
            or Product Supply is alleged or proven to be the subject of a
            recall, market withdrawal or correction in any country in the Wyeth
            Territory. Immunex and Wyeth shall cooperate in the handling and
            disposition of such recall, market withdrawal or correction in the
            Wyeth Territory; provided, however, that in the event of
            disagreement as to any matters related to such recall, market
            withdrawal or correction, other than the determination of who shall
            bear the costs as set forth in the immediately following sentence,
            Wyeth, after consultation with Immunex, shall have final authority
            with respect to such matters in the Wyeth Territory, which authority
            shall be exercised reasonably in and in good faith. Wyeth shall bear
            the cost of all recalls, market withdrawals, or corrections of Bulk
            Drug Substance, Finished Product, Drug Product, or Product Supply in
            the Wyeth Territory unless such recall, market withdrawal or
            correction shall have been the result of any breach of Immunex's
            covenants, representations, or warranties set forth in this
            Agreement or shall have been the result of Immunex's grossly
            negligent breach of any of its obligations hereunder, in which case
            Immunex shall, upon substantiation, bear the cost of such recall,
            market withdrawal, or correction. Wyeth or its agent shall in all
            events be responsible for conducting any recalls, market withdrawals
            or corrections with respect to Bulk Substance, Finished Product,
            Drug Product, or Product Supply in the Wyeth Territory.

8.10  Safety Agreement.

      Immunex and Wyeth shall comply with the provisions of the Safety
      Agreement. To the extent possible, the provisions of the Safety Agreement
      shall be interpreted consistently with the provisions of this Agreement.
      In the event of a conflict between the provisions of the Safety Agreement
      and the provisions of this Agreement, the provisions of this Agreement
      shall control.

                Article 9. Pricing of Product Between the Parties

9.1   Standard Product Prices.

      (a)   Calculation. For each Calendar Year (or portion thereof remaining in
            the Term) for which a Five-Year Plan is in effect, a "Standard
            Product Price" for


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            Bulk Drug Substance manufactured at each of the Sites will be
            established, [*], as further described below. A separate Standard
            Product Price shall be calculated for Bulk Drug Substance
            manufactured using [*], Bulk Substance manufactured using the T1
            Process, and Bulk Drug Substance manufactured using the T2 Process,
            if each such Manufacturing Process is being used at one or more
            Sites, and all references to calculation or adjustment of the
            Standard Product Price shall include all such Standard Product
            Prices, if applicable.

            (i)   RI Site and BIOS Site. For the RI Site and the BIOS Site, the
                  Standard Product Price shall be calculated, for a particular
                  Calendar Year, by [*]

                  In such calculation, the Fully Absorbed Manufacturing Cost
                  shall first be allocated between all Released Bulk Drug
                  Substance for which the release is completed during such
                  Calendar Year and Bulk Drug Substance that is Work In Process
                  at the end of such Calendar Year. The Fully Absorbed
                  Manufacturing Cost for all Released Bulk Drug Substance for
                  which the release is completed during such Calendar Year shall
                  be included, and the Fully Absorbed Manufacturing Cost for
                  Bulk Drug Substance that is Work In Process at the end of such
                  Calendar Year shall be carried over and used in calculating
                  the Standard Product Price in the Calendar Year that such Bulk
                  Drug Substance is released. The Standard Product Price for the
                  RI Site and the BIOS Site shall not include any Excluded
                  Supply, unless the Excluded Supply is manufactured in the same
                  manufacturing facility at the Site as the Subject Capacity, in
                  which case Excluded Supply shall be included in both
                  subsections (A) and (B) of the calculation above.

            (ii)  BIP Site. For Product manufactured at the BIP Site, the
                  Standard Product Price for Bulk Drug Substance will be
                  calculated, for a particular Calendar Year, by [*]

                  The Standard Product Price shall be calculated for Bulk Drug
                  Substance to be purchased by the Parties, whether purchased in
                  the form of Bulk Drug Substance itself or as incorporated into
                  Drug Product or Finished Product. If incorporated into Drug
                  Product or Finished Product, the Standard Product Price will
                  be calculated based on the portion of the price attributable
                  to Bulk Drug Substance.

      (b)   Schedule for Establishing Standard Product Prices.

            (i)   BIP Site. Within [*] after the Effective Date, and thereafter
                  on or before [*] of each Calendar Year, the Parties shall
                  submit to each other in writing the total quantity of Product
                  that each plans to purchase from BIP during the following
                  Calendar Year in accordance with the binding Supply Allocation
                  for such Calendar Year in the Five-Year Plan, along

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                  with the cost of the Bulk Drug Substance used in such Product
                  in U.S. dollars. The Parties shall cooperate in good faith in
                  using such information to determine the Standard Product Price
                  for Bulk Drug Substance for the BIP Site.

            (ii)  RI and BIOS Sites. Immunex shall be responsible for
                  establishing the Standard Product Price for the RI Site. Wyeth
                  shall be responsible for establishing the Standard Product
                  Price for the BIOS Site. Within [*] after the Effective Date,
                  and thereafter on or before [*] of each Calendar Year, each
                  Party shall submit to the other in writing (A) the Standard
                  Product Price for the following Calendar Year for the Site(s)
                  for which it bears responsibility according to the previous
                  sentence, and (B) its planned purchases from the Site owned by
                  the other Party (pursuant to the applicable Five-Year Plan
                  issued by the JSC) during the following Calendar Year, and (c)
                  the quantity of Bulk Drug Substance deriving from the Subject
                  Capacity at its own Site that such Party plans to manufacture
                  for its own use.

            (iii) Finalizing Standard Product Prices and Projected Blended
                  Price. Within thirty (30) days after receiving the initial
                  submissions pursuant to Section 9.1(b)(i) and (ii) above, and
                  thereafter by no later than [*] of each subsequent Calendar
                  Year, the Parties shall agree upon in writing (A) the Standard
                  Product Prices for all of the Sites for the upcoming Calendar
                  Year, and (B) the projected Blended Price for the upcoming
                  Calendar Year. The JSC shall resolve any disputes between the
                  Parties with regard to the Standard Product Prices and the
                  projected Blended Price, and the Parties shall agree upon in
                  writing no later than December 1 of each Calendar Year the
                  Standard Product Prices for all Sites and the projected
                  Blended Price for the upcoming Calendar Year. The Standard
                  Product Prices and Blended Price shall be established in U.S.
                  dollars, and the Parties' finance representatives shall
                  negotiate in good faith to determine the exchange rate to be
                  used in calculating the Standard Product Prices for the BIP
                  Site and the BIOS Site. Each Party may enter into hedging
                  contracts related to currency exchange, but such contracts
                  will not be considered in calculation of the quarterly
                  settlement pursuant to Section 9.3 below.

            (iv)  Updating Standard Product Prices and Blended Price. Each Party
                  shall [*] submit to the other Party any necessary adjustments
                  to (a) the Standard Product Price for its Site, (b) the
                  quantity and timing of its purchases from the BIP Site or the
                  other Party's Site for the then-current Calendar Year, or (c)
                  the quantity of Bulk Drug Substance deriving from the Subject
                  Capacity at its own Site that such Party plans to manufacture
                  for its own use. Each Party shall make such submissions
                  updating such information for past, then-current, and future
                  Calendar Quarters in the

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                  then-current Calendar Year by no later than [*]. Based upon
                  any such updated information, the Parties shall agree upon any
                  updated Standard Product Prices (the "Adjusted Standard
                  Product Price") and projected Blended Price for the
                  then-ongoing Calendar Year.

      (c)   Example. An example of the calculation of Standard Product Prices is
            set forth on Exhibit A1 attached hereto.

9.2   Purchase Price.

      A Party purchasing Bulk Drug Substance from one of the Sites hereunder
      during a Calendar Year shall pay the Standard Product Price applicable to
      such Site and to the form of the Manufacturing Process used to manufacture
      such Bulk Drug Substance (e.g., [*], the T1 Process, or the T2 Process)
      for such Calendar Year, as established pursuant to Section 9.1(b)(iii)
      above. Notwithstanding the foregoing, if the Standard Product Price for
      Bulk Drug Substance for the BIP Site differs from the applicable price due
      to BIP under the Enbrel Supply Agreement, the Party purchasing from BIP
      shall pay the amount therefor set forth in the Enbrel Supply Agreement.
      If, during such Calendar Year, the Standard Product Price for a Site is
      adjusted pursuant to Section 9.1(b)(iv) above, the original Standard
      Product Price established pursuant to Section 9.1(b)(iii) above shall
      continue to apply to purchases of Bulk Drug Substance from such Site, and
      settlement to the Adjusted Standard Product Price shall occur during the
      quarterly settlements described in Section 9.3(b) below.

9.3   Blended Price; Quarterly Settlement.

      (a)   Adjustments to Projections. Within [*] following the end of each
            Calendar Quarter, each Party shall submit to the other Party the
            following information, if applicable and if not already submitted
            pursuant to Section 9.1(b)(iv) above:

            (i)   Any adjustments to the quantity or price of Bulk Drug
                  Substance for Product that such Party purchased from BIP,
                  compared to the projections of such purchases that were used
                  in calculating the Standard Product Price for the BIP Site for
                  the applicable Calendar Year;

            (ii)  Any adjustments to the quantity of Bulk Drug Substance that
                  such Party purchased from the Site owned by the other Party,
                  or to the quantity of Bulk Drug Substance manufactured at such
                  Party's own Site for its own use, compared to the previous
                  projections of such purchases that were used in calculating
                  the Blended Price for the current Calendar Year; and

            (iii) Any adjustments to the Fully Absorbed Manufacturing Cost for
                  Bulk Drug Substance manufactured at the Site owned by such
                  Party, or the applicable Inventory Carrying Costs, compared to
                  the projections made in calculating the Standard Product Price
                  for such Site for such Calendar Year.

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            In addition, if a Party at any other time becomes aware of a
            material variance in actual performance, compared to projections
            used in calculating the Standard Product Price, for any of the items
            set forth in Sections 9.3(a)(i)-(iii) above, then such Party shall
            provide written notice to the other Party of such variance as soon
            as reasonably practicable, and the JSC shall make any necessary
            adjustments to the Standard Product Price and the Blended Price.

      (b)   Settlement to Adjusted Standard Product Price. Each Calendar
            Quarter, according to the schedule set forth in Section 9.4 below,
            the finance representatives designed by the Parties as set forth in
            Section 9.5(b) shall settle Calendar Year-to-date purchases of Bulk
            Drug Substance, made at the initial Standard Product Prices, to the
            Adjusted Standard Product Prices. The settlement due from one Party
            to the other Party shall be calculated by:

            (i)   determining the difference between (A) Calendar Year-to-date
                  purchases, multiplied by the Adjusted Standard Product Price,
                  and (B) Calendar Year-to-date purchases, multiplied by the
                  Standard Product Price, and

            (ii)  subtracting therefrom the previous Calendar Year-to-date
                  settlements made to the Adjusted Standard Product Price under
                  this Section 9.3(b).

      (c)   Calculation of Blended Price and Settlement. Each Calendar Quarter,
            according to the schedule set forth in Section 9.4 below, the
            finance representatives designated by the Parties as set forth in
            Section 9.5(b) shall jointly make the following calculations.

            (i)   The finance representatives shall calculate the Blended Price
                  applicable to such Calendar Quarter, based on [*]. A separate
                  Blended Price shall be calculated for Bulk Drug Substance
                  manufactured using [*], Bulk Substance manufactured using the
                  T1 Process, and Bulk Drug Substance manufactured using the T2
                  Process, if each such Manufacturing Process is being used at
                  one or more Sites.

            (ii)  The finance representatives shall determine the settlement due
                  from one Party to another by calculating:

                  (A)   the difference between (I) the cumulative Calendar
                        Year-to-date purchases of Bulk Drug Substance purchased
                        by each Party from all Sites, multiplied by the Blended
                        Price as calculated in Section 9.3(c)(i) above, and (II)
                        the cumulative Calendar Year-to-date purchases of Bulk
                        Drug Substance purchased by each Party from all Sites
                        multiplied by the applicable Adjusted Product Prices,

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                  (B)   and subtracting therefrom the previous Calendar
                        Year-to-date settlements made to the Blended Price under
                        this Section 8.3(c).

            An example of the calculation of the Blended Price Settlement is set
            forth on Exhibits A2 and A3 attached hereto.

9.4   Consolidated Reporting and Forecasting.

      The finance representatives designated by the Parties as set forth in
      Section 9.5(b) shall jointly perform consolidated reporting for the
      Collaboration. The finance representatives will provide each other with
      financial information prepared in accordance with the terms contained in
      this Agreement for preparation of the consolidated reports according to
      the schedule set forth herein. The finance representatives shall negotiate
      in good faith to resolve any issues arising during the preparation of
      consolidated reports, if the issue cannot be resolved, shall refer such
      dispute to the JSC. Subject to resolution of any issues by the JSC, the
      consolidated reporting shall be binding on the Parties, subject to Section
      11.2 below, and the Party who owes the other Party a cash settlement shall
      pay the other Party the amount owed no later than [*] days following the
      close of the Calendar Quarter at issue, as further set forth in Section
      11.1 below.

9.5   Accounting and Financial Reporting.

      (a)   Reporting. Each Party shall report costs in a manner consistent with
            GAAP, the terms hereof and such Party's project cost system. Each
            Party's financial representative will disclose the project cost
            system methodologies used, as well as any material changes thereto,
            to the other Party's financial representative.

      (b)   Finance Representatives. Each Party shall appoint a representative
            from its finance department with expertise in the areas of
            accounting, cost allocation, budgeting, and financial reporting to
            assist in the matters addressed by this Article 9. Each such
            representative shall act as its Party's finance manager hereunder
            reporting to the JSC, with authority and responsibility for
            determining financial accounting and reporting methods, reports,
            budgets and forecasts. Such representatives shall also provide
            services to and consult with the JSC in order to address any
            financial, budgetary and accounting issues that arise in connection
            with each Five-Year Plan. Each Party may designate a substitute
            financial representative to perform such functions temporarily or
            may replace its designated financial representative at any time by
            providing notice thereof to the other Party.

    Article 10. Relationship with BIP, Catalytica, and Third Party Licensors

10.1  Relationship with BIP.

      [*]

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                                       36



10.2  Relationship with Catalytica.

      The Catalytica Supply Agreement sets forth the [*]. During the term of the
      Catalytica Supply Agreement, the Parties shall abide by the terms thereof
      [*]. Neither Party shall take any action with Catalytica that such Party
      knows would interfere with fulfillment of a Five-Year Plan established
      hereunder.

10.3  Third Party Royalties.

      Immunex has entered into certain license agreements that require royalties
      to be paid upon sales of Product Supply Units (collectively, the "Immunex
      License Agreements"). Immunex shall enter into sublicense agreements with
      Wyeth, pursuant to which Wyeth will receive certain rights and licenses to
      use the technology of the licensors' in the Immunex License Agreement (the
      "Sublicense Agreements"). Each Sublicense Agreement will state any fees or
      other obligations owed by Wyeth to Immunex in consideration for such
      rights and licenses.

                    Article 11. Payment of Amounts Due; Audit

11.1  Payment of Amounts Due.

      (a)   Invoices; Payment. Each Party shall invoice the other Party for any
            amounts owed pursuant to Article 9 hereunder. Subject to Section
            11.1(c) below, such invoices shall be paid within [*] days after
            receipt thereof. Section 9.4 shall govern the procedure for payments
            between the Parties related to settlement to Blended Price; no
            invoices shall be required. All payments made by the Parties
            hereunder shall be made in U.S. dollars by bank wire transfer in
            immediately available funds to an account designated by the Party
            receiving payment.

      (b)   Disputes. Any disputes concerning amounts due shall be referred to
            the finance representatives designated by the Parties as set forth
            in Section 9.5(b). The finance representatives shall negotiate in
            good faith to resolve any such disputes. If the finance
            representatives are unable to resolve any disputes concerning
            amounts due, they will refer such disputes to the JSC for
            resolution.

      (c)   Late Payments. For any amounts that one Party owes to the other
            Party according to Section 9.4 or 11.1(a) above, and which the
            paying Party has not paid within the time period set forth in such
            section, the paying Party shall increase the amount otherwise due
            and payable by adding interest thereon, computed at the rate of [*]
            per annum, as of the date on which payment was due.

11.2  Audits and Interim Review.

      Each Party shall maintain accurate books and records in accordance with
      GAAP and the terms hereof, supporting the calculation of Standard Product
      Prices, Adjusted Standard Product Prices, quantities of Product purchased
      and sold by such Party, Blended Prices, and amounts invoiced and paid by
      such

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                                       37



      Party pursuant to Section 11.1 above, for [*] years following the end of
      the Calendar Year to which such records pertain, or for such longer period
      required by an Immunex License Agreement, provided that Immunex notifies
      Wyeth of such longer period in writing. The period subject to audit will
      extend for a maximum period of [*] years preceding the then current
      Calendar Year. A Party, or its independent public accountants reasonably
      acceptable to the other Party, may have access to the books and records
      subject to audit of the other Party during normal business hours to
      conduct a review or audit of such books and records, solely and to the
      extent necessary to confirm the accuracy of the amounts reported and
      calculated in accordance with the terms hereof; provided, however, that a
      Party conducting such an audit must provide the other Party at least [*]
      days' prior written notice and may not conduct such an audit more than
      once in any [*] during the Term or more than once following the Term. Any
      payment made by the Party being audited to the other Party as a result of
      such an audit shall include interest from the date due, calculated as set
      forth in Section 11.1(b) above. Any such inspection or audit shall be at
      the expense of the Party conducting it; provided, however, that if such
      accountants reasonably determine that the Party conducting the audit has
      overpaid or underpaid the other Party by an amount equal to or greater
      than [*] percent [*] in the period of time within the scope of the audit,
      the other Party shall pay all reasonable fees and expenses incurred by
      such accountants in making such determination. Any accounting firm
      conducting such an audit shall enter into a confidentiality agreement
      reasonably acceptable to both Parties limiting the disclosure and use of
      information contained in such books and records. In the event that an
      audit performed in accordance with this Section 11.2 does not resolve the
      dispute between the Parties, then such dispute shall be referred to the
      JSC pursuant to Section 3.4 above.

      Article 12. Representations and Warranties; Limitation of Liabilities

12.1  Wyeth.

      Wyeth hereby represents and warrants to Immunex that:

      (a)   Wyeth has the corporate power and authority and the legal right to
            enter into this Agreement and to perform its obligations hereunder;
            and

      (b)   Wyeth has taken all necessary corporate action on its part to
            authorize the execution and delivery of this Agreement and the
            performance of its obligations hereunder. This Agreement has been
            duly executed and delivered on behalf of Wyeth, and constitutes a
            legal, valid, binding obligation, enforceable against Wyeth in
            accordance with its terms.

12.2  Immunex.

      Immunex hereby represents and warrants to Wyeth that:

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                                       38



      (a)   Immunex has the corporate power and authority and the legal right to
            enter into this Agreement and to perform its obligations hereunder;
            and

      (b)   Immunex has taken all necessary corporate action on its part to
            authorize the execution and delivery of this Agreement and the
            performance of its obligations hereunder. This Agreement has been
            duly executed and delivered on behalf of Immunex, and constitutes a
            legal, valid, binding obligation, enforceable against Immunex in
            accordance with its terms.

                           Article 13. Indemnification

13.1  Indemnification by Immunex.

      Immunex shall indemnify, defend, and hold Wyeth, its Affiliates, and its
      and their respective directors, officers, employees and agents, harmless
      from and against all losses, damages, liabilities, settlements, penalties,
      fines, costs, and expenses (including, without limitation, reasonable
      attorneys' fees and expenses) (collectively, the "Liabilities") to the
      extent such Liabilities arise out of or result from (i) any claim, lawsuit
      or other action by a Third Party caused by the manufacture, use, handling,
      distribution, marketing, or sale of the Bulk Drug Substance, Drug Product,
      Finished Product, or Product Supply in the Immunex Territory, (ii) any
      material breach by Immunex of its representations, warranties, and
      covenants made hereunder, and/or (iii) Immunex's grossly negligent acts or
      omissions or willful misconduct. Notwithstanding the foregoing, Immunex's
      indemnification obligation hereunder shall not apply to the extent that
      any particular Liability arises out of or results from (y) any material
      breach by Wyeth of its representations, warranties, or covenants made
      hereunder, and/or (z) Wyeth's grossly negligent acts or omissions or
      willful misconduct.

13.2 Indemnification by Wyeth.

      Wyeth shall indemnify, defend, and hold Immunex, its Affiliates, and their
      respective directors, officers, employees, and agents harmless from and
      against all Liabilities arise out of or result from (i) any claim,
      lawsuit, or other action by a Third Party caused by the manufacture, use,
      handling, distribution, marketing, or sale of the Bulk Drug Substance,
      Drug Product, Finished Product, or Product Supply in the Wyeth Territory,
      (ii) any material breach by Wyeth of its representations, warranties, and
      covenants made hereunder, and/or (iii) Wyeth's grossly negligent acts or
      omissions or willful misconduct. Notwithstanding the foregoing, Wyeth's
      indemnification obligation hereunder shall not apply to the extent that
      any particular Liability arises out of or results from (y) any material
      breach by Immunex of its representations, warranties, or covenants made
      hereunder, and/or (z) Immunex's grossly negligent acts or omissions or
      willful misconduct.

13.3  Indemnification Procedures.

      A person (the "Indemnitee") which intends to claim indemnification under
      Section 13.1 or 13.2 hereof shall promptly notify the Party indemnifying
      hereunder (the "Indemnitor") in writing of any claim, lawsuit or other
      action in


                                       39



      respect of which the Indemnitee or any of its directors, officers,
      employees, agents or Affiliates intend to claim such indemnification. The
      Indemnitee shall permit, and shall cause its directors, officers,
      employees, agents, and Affiliates to permit, the Indemnitor, at its
      discretion, to settle any such claim, lawsuit or other action and agrees
      to the complete control of such defense or settlement by the Indemnitor;
      provided, however, that such settlement does not adversely affect the
      Indemnitee's rights hereunder or impose any obligations on the Indemnitee
      in addition to those set forth herein in order for it to exercise such
      rights. No such claim, lawsuit or other action shall be settled without
      the prior written consent of the Indemnitor and the Indemnitor shall not
      be responsible for any legal fees or other costs incurred other than as
      provided herein. The Indemnitee, its directors, officers, employees,
      agents and Affiliates shall cooperate fully with the Indemnitor and its
      legal representatives in the investigation and defense of any claim,
      lawsuit or other action covered by this indemnification. The Indemnitee
      shall have the right, but not the obligation, to be represented by counsel
      of its own selection and expense.

                        Article 14. Term and Termination

14.1  Term.

      The initial term (the "Initial Term") of this Agreement shall begin as of
      the Effective Date and shall continue, unless earlier terminated as set
      forth in Section 14.2 below, until the later of (a) [*] years after the
      Effective Date, or (b) the expiration or termination of the Enbrel Supply
      Agreement. The Parties may extend this Agreement beyond the Initial Term
      for periods of [*] or more (any such period, an "Additional Term"), by
      mutual written agreement entered into by the Parties at least [*] years
      prior to the expiration of the Initial Term or Additional Term, as
      applicable. If an Additional Term is for a period of less than [*] years,
      the Parties may extend the Agreement beyond such Additional Term for
      periods of [*] or more by mutual written agreement entered into by the
      Parties at least [*] prior to the expiration of the Additional Term. The
      Initial Term plus any Additional Terms shall constitute the "Term" of this
      Agreement.

14.2  Termination.

      This Agreement may be terminated prior to the period set forth in Section
      14.1 above as follows:

      (a)   Mutual Agreement. This Agreement may be terminated in its entirety
            at any time upon mutual written agreement between Immunex and Wyeth
            signed by a duly authorized executive officer of each Party.

      (b)   Material Breach.

            (i)   This Agreement may be terminated in its entirety by either
                  Immunex or Wyeth upon written notice to the other Party in the
                  event of a material breach by the other Party which is not
                  cured within [*] days from written

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                                       40



                  notice to the breaching Party specifying in reasonable detail
                  the nature of such breach or longer if the breaching Party
                  delivers a certificate that such material breach is not
                  reasonably capable of being cured within [*] days and that the
                  breaching Party is working diligently to cure such breach, but
                  in no event shall the time for curing such breach exceed an
                  additional [*] days.

            (ii)  Except as expressly stated otherwise herein, remedies
                  hereunder are cumulative, and nothing in this Agreement shall
                  prevent either Party, in the case of a breach, from not
                  terminating this Agreement and seeking to enforce its rights
                  hereunder.

14.3  Consequences of Termination.

      (a)   Amounts Outstanding. Expiration or termination of this Agreement for
            any reason shall not exempt either Immunex or Wyeth from paying to
            the other Party any amounts due to such Party under this Agreement
            and outstanding at the time of such expiration or termination.

      (b)   Transitional Supply Obligation. In the event of termination of this
            Agreement by either Party pursuant to Section 14.2(b) above, the
            breaching Party shall, at the request of the non-breaching Party,
            continue to supply the Product to the non-breaching Party until such
            time as a new supplier for the Product has been approved by the
            applicable regulatory authorities in the non-breaching Party's
            Territory; provided, however, that unless otherwise agreed upon, the
            breaching Party shall not be required to supply the Product longer
            than [*]. The breaching Party shall supply the non-breaching Party
            with the quantities of Product that the breaching Party is obligated
            to supply according to the Supply Allocation included [*].

      (c)   Willful Breach. In the event that either Party willfully breaches
            its obligation to supply Product to the other Party in accordance
            with the terms set forth in Articles 4, 5, or 6 hereof, the
            non-breaching Party shall be entitled to recover its incidental,
            special, and consequential damages incurred as result of such
            willful breach, in addition to any other remedies that the
            non-breaching Party may have at law or in equity. EXCEPT AS SET
            FORTH IN THE PRECEDING SENTENCE, NEITHER PARTY SHALL HAVE THE RIGHT
            TO RECOVER INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES ARISING
            FROM OR RELATED TO BREACH BY THE OTHER PARTY OF THIS AGREEMENT.

14.4  Specific Performance.

      The Parties agree that irreparable damage would occur in the event any
      provision of this Agreement was not performed in accordance with the terms
      hereof and that the Parties shall be entitled to specific performance of
      the terms of this Agreement, in addition to any other remedy at law or
      equity.

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                                       41



14.5  Rights Not Exclusive.

      All rights to terminate, all rights upon termination, and all rights to
      seek specific performance are in addition to other remedies in law or
      equity that may be available to either Party.

                           Article 15. Confidentiality

15.1  Confidentiality Obligations.

      Except as permitted elsewhere under this Agreement, each Party agrees to
      take Reasonable Steps (as defined in this Section 15.1) (a) to receive and
      maintain the Confidential Information of the other Party in confidence,
      (b) not to disclose such Confidential Information to any Third Party
      without the written consent of the disclosing Party, and (c) to promptly
      notify the disclosing Party upon learning of any law, rule, regulation, or
      court order that purports to compel disclosure of any Confidential
      Information of the disclosing Party and to reasonably cooperate with the
      disclosing Party, at the disclosing Party's expense, in the exercise of
      the disclosing Party's right to protect the confidentiality of such
      Confidential Information. Neither Party hereto shall use all or any part
      of the Confidential Information of the other Party for any purpose other
      than to perform its obligations under this Agreement. The Parties will
      take Reasonable Steps (as defined in this Section 15.1) to ensure that
      their employees, representatives, and agents comply with this provision,
      and will be responsible for any breach by such employees, representatives,
      and agents. As used herein, "Reasonable Steps" means at least the same
      degree of care that the receiving Party uses to protect its own
      Confidential Information, and in, any event, no less than reasonable care.

15.2  Exclusions.

      Nothing contained herein shall prevent a Party from disclosing
      Confidential Information pursuant to any applicable law, rule, regulation,
      or court order; provided, however, that such Party complies with the
      notice provisions of Section 15.1(c) to the extent permissible under
      applicable laws, rules, regulations, or court orders. Such disclosure
      shall not alter the status of such information hereunder for all other
      purposes as Confidential Information.

15.3  Remedies.

      Each Party acknowledges and agrees that the provisions of this Article 15
      are reasonable and necessary to protect the other Party's interests in its
      Confidential Information, that any breach of the provisions of this
      Article 15 may result in irreparable harm to such other Party, and that
      the remedy at law for such breach may be inadequate. Accordingly, in the
      event of any breach or threatened breach of the provisions of this Article
      15 by a party hereto, the other Party, in addition to any other relief
      available to it at law in equity or otherwise, shall be entitled to seek
      temporary and permanent injunctive relief restraining the breaching Party
      from engaging in and/or continuing any conduct that would constitute a
      breach of this Article 15, without the necessity of proving actual damages
      or posting a bond or other security.


                                       42



15.4  Publications.

         No announcement, news release, public statement, publication, or
         presentation relating to the existence of this Agreement, the subject
         matter herein, or either Party's performance hereunder (collectively, a
         "Publication") shall be made without the other Party's prior approval;
         provided, however, that either Party may make such Publication or
         disclosure as is deemed necessary, in the reasonable judgment of the
         responsible Party, to comply with federal or state laws or regulations.
         Each Party agrees to submit such Publication it proposes to make to the
         other Party for purposes of such other Party's review and comment or,
         if required pursuant to this Section 15.4, approval. Any such
         disclosure will not contain confidential business or technical
         information of the other Party, unless if disclosure of such
         confidential business or technical information is required by law or
         regulation, in which case the disclosing Party will redact if
         permissible by such law or regulation, or otherwise make reasonable
         efforts to minimize such disclosure and obtain confidential treatment
         for any such information which is disclosed by requirement of such law
         or regulation. Except as otherwise required by such law or regulation,
         the Party whose Publication has been reviewed shall consider in good
         faith the removal of any information the reviewing Party reasonably
         deems to be inappropriate for disclosure. Each Party further agrees to
         respond as promptly as reasonably practicable to a proposed Publication
         in accordance with timelines agreed upon by the Parties, and likewise
         agrees that it shall not unreasonably withhold approval of such
         Publication.

                            Article 16. Force Majeure

16.1  Effects of Force Majeure.

      Neither Immunex nor Wyeth shall be in breach of this Agreement if there is
      any failure of performance under this Agreement (except for payment of any
      amounts due hereunder) occasioned by any act of God, fire, act of
      government or state, war, civil commotion, insurrection, embargo,
      prevention from or hindrance in obtaining energy or other utilities, labor
      disputes of whatever nature or any other reason beyond the control and
      without the fault or negligence of the Party affected thereby (a "Force
      Majeure Event"). Such excuse shall continue as long as the Force Majeure
      Event continues. Upon cessation of such Force Majeure Event, the affected
      Party shall promptly resume performance hereunder.

16.2  Notice of Force Majeure.

      Each Party agrees to give the other Party prompt written notice of the
      occurrence of any Force Majeure Event, the nature thereof, and the extent
      to which the affected Party will be unable fully to perform its
      obligations hereunder. Each Party further agrees to use reasonable efforts
      to correct the Force Majeure Event as quickly as possible and to give the
      other Party prompt written notice when it is again fully able to perform
      such obligations.


                                       43



16.3  Supply Shortage Caused by Force Majeure.

      If a Force Majeure Event occurs, the JSC shall determine whether it has
      caused a Supply Shortage, and if so, the JSC shall make any corresponding
      adjustments to the then-current Five-Year Plan.

                             Article 17. Assignment

17.1  Assignment.

      This Agreement shall be binding upon the successors and assigns of each
      Party and the name of a Party appearing herein shall be deemed to include
      the names of its successors and assigns. Neither Party may assign its
      interest under this Agreement without the prior written consent of the
      other Party, which consent shall not be unreasonably withheld; provided,
      however, that either Party may assign its interest under this Agreement,
      without the prior written consent of the other Party, (a) to an Affiliate,
      so long as the assigning Party unconditionally guarantees the obligations
      of such Affiliate or (b) to a successor to the assigning Party's business
      by reason of merger, sale of all or substantially all of its assets or
      other form of acquisition, provided that such successor agrees in writing
      to assume all of the obligations of the assigning Party under this
      Agreement. Any purported assignment without a required consent shall be
      void. No assignment shall relieve either Party of responsibility for the
      performance of any obligation that accrued prior to the effective date of
      such assignment.


                                       44



                         Article 18. Dispute Resolution

18.1  Dispute Resolution.

      The Parties recognize that a bona fide dispute as to certain matters may
      from time to time arise during the term of this Agreement that relates to
      a Party's rights and/or obligations hereunder. In the event of the
      occurrence of such a dispute, either Party may, by written notice to the
      other Party, have such dispute referred to their respective officers
      designated below, or their designees, for attempted resolution by good
      faith negotiations within thirty (30) days after such written notice is
      received. Such designated officers are as follows:

      For Immunex - Chief Operating Officer

      For Wyeth - President

      In the event the designated officers are not able to resolve such dispute
      within such thirty (30)-day period, or such other period of time as the
      Parties may mutually agree in writing, each Party shall have the right to
      pursue any and all remedies available at law or in equity.

18.2  Certain Disputes. Notwithstanding the foregoing, this Article 18 shall not
      apply to any disputes arising under Article 13 (Indemnification) or
      Article 15 (Confidentiality) hereunder. Disputes arising under the Quality
      Agreement shall be governed by the process set forth in Article 9 therein.

                            Article 19. Miscellaneous

19.1  Notices.

      Any notice required or permitted to be given hereunder by either Party
      shall be in writing and shall be (a) delivered personally, (b) sent by
      registered mail, return receipt requested, postage prepaid, (c) sent by a
      nationally-recognized courier service guaranteeing next-day or second day
      delivery, charges prepaid, or (d) delivered by facsimile (with the
      original promptly sent by any of the foregoing manners), to the addresses
      or facsimile numbers of the other Party set forth below, or at such other
      addresses as may from time to time be furnished by similar notice by
      either Party. The effective date of any notice hereunder shall be the date
      of receipt by the receiving Party.

      If to Immunex:   Immunex Corporation
                       51 University Street
                       Seattle, Washington 98101
                       Attention:  Chief Operating Officer
                       Fax: (206) 292-9271
                       Phone: (206) 587-0430


                                       45



      with a copy to:  Immunex Corporation
                       51 University Street
                       Seattle, Washington 98101
                       Attention: General Counsel
                       Fax: (206) 292-9271
                       Phone: (206) 587-0430

      If to Wyeth:     Wyeth-Ayerst Laboratories
                       555 E. Lancaster
                       St. Davids, Pennsylvania 19807
                       Attention: Senior Vice President, Global Business
                                  Development
                       Fax: (610) 688-9498
                       Phone: (610) 971-5809

      with a copy to:  American Home Products Corporation
                       Five Giralda Farms
                       Madison, New Jersey 07940
                       Attention: General Counsel
                       Fax: (973) 660-7050
                       Phone: (973) 660-6040

19.2  Applicable Law.

      This Agreement shall be construed and the respective rights of the Parties
      determined in accordance with the laws of the State of New Jersey, without
      regard to conflicts of law. The Parties expressly exclude the application
      to this Agreement of the United Nations Convention on Contracts for the
      International Sale of Goods.

19.3  Headings.

      The table of contents and all headings in this Agreement are for
      convenience of reference only and shall not affect the interpretation of
      this Agreement.

19.4  Exhibits.

      All exhibits referred to herein form an integral part of this Agreement
      and are incorporated into this Agreement by such reference.

19.5  Severability.

      Both Parties hereby expressly agrees that they have no intention to
      violate any public policy, statutory or common laws, rules, regulations,
      treaty or decision of any government agency or executive body thereof of
      any country or community or association of countries; that if any word,
      sentence, paragraph, clause or combination thereof in this Agreement is
      found by a court or executive body with judicial powers having
      jurisdiction over this Agreement or either Party hereto, in a final
      unappealed order, to be in violation of any such provisions in any country
      or community or association of countries, such words, sentences,
      paragraphs, clauses or combination shall be inoperative in such country or
      community or association of countries and the remainder of this Agreement
      shall remain binding upon the Parties, so long as


                                       46



      enforcement of the remainder does not violate the Parties' overall
      intentions in this transaction.

19.6  Waiver.

      No waiver of any term, provision or condition of this Agreement whether by
      conduct or otherwise in any one or more instances shall be deemed to be or
      construed as a further or continuing waiver of any such term, provision or
      condition or of any other term, provision or condition of this Agreement.

19.7  Construction.

      The Parties agree that each Party and its counsel has reviewed this
      Agreement and that any rule of construction to the effect that ambiguities
      are to be resolved against the drafting party shall not apply to the
      interpretation of this Agreement.

19.8  Counterparts.

      This Agreement and any amendment hereto may be executed in any number of
      counterparts, each of which shall for all purposes be deemed to be an
      original and all of which shall constitute the same instrument.

19.9  Entirety; Amendments.

      This Agreement, including any exhibits attached hereto and referenced
      herein, constitutes the full understanding of the Parties and a complete
      and exclusive statement of the terms of their agreement with respect to
      the specific subject matter hereof, and no terms, conditions,
      understandings or agreements purporting to modify or vary the terms
      thereof shall be binding unless it is hereafter made in writing and signed
      by both Parties. The MOU is superceded by this Agreement and is of no
      further force and effect. After RI Approval, the Short-Term Allocation
      Agreement shall be superceded by this Agreement and shall be of no further
      force and effect. No modification to this Agreement shall be effected by
      the acknowledgment or acceptance of any purchase order or shipping
      instruction forms or similar documents containing terms or conditions at
      variance with or in addition to those set forth herein. In the event of a
      conflict between this Agreement and the exhibits hereto, the terms of this
      Agreement shall control. In the event of a conflict between this Agreement
      and the terms of the TNFR Agreement, the terms of this Agreement shall
      control. In the event of a conflict between this Agreement and the terms
      of the Enbrel Supply Agreement, the terms of the Enbrel Supply Agreement
      shall control. This Agreement may be amended and supplemented only by a
      written instrument signed by both Parties.

                   [This space is intentionally left blank.]


                                       47



IN WITNESS WHEREOF, Immunex and Wyeth have caused this Agreement to be executed
as of the Effective Date.

IMMUNEX CORPORATION                         AMERICAN HOME PRODUCTS
                                            CORPORATION, acting through its
                                            Wyeth-Ayerst Laboratories division


By: /s/ David A. Mann                       By:  /s/ Kenneth J. Martin
   ----------------------------------          ---------------------------------

Name: David A. Mann                         Name: Kenneth J. Martin
     --------------------------------            -------------------------------

       Executive Vice President and
Title: Chief Financial Officer              Title: Senior Vice President Finance
      -------------------------------             ------------------------------

Date:  November 6, 2001                     Date:  November 6, 2001
     --------------------------------            -------------------------------


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