12,567,610 Shares of Common Stock, 22,214,990 Prefunded Warrants (to purchase 22,214,990 shares of Common Stock) and 34,782,600 Common Warrants (to purchase 34,782,600 shares of Common Stock) SIENTRA, INC. UNDERWRITING AGREEMENT

Exhibit 1.1

12,567,610 Shares of Common Stock,

22,214,990 Prefunded Warrants (to purchase 22,214,990 shares of Common Stock) and

34,782,600 Common Warrants (to purchase 34,782,600 shares of Common Stock)

SIENTRA, INC.

UNDERWRITING AGREEMENT

October 21, 2022

▇▇▇▇▇-▇▇▇▇▇▇ Capital Group LLC

As representative of the Underwriters

named in Schedule I hereto

▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇

▇▇▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

Sientra, Inc., a Delaware corporation (the “Company”), proposes to issue and sell to the underwriters named in Schedule I hereto (the “Underwriters”) for whom ▇▇▇▇▇-▇▇▇▇▇▇ Capital Group LLC is acting as representative (the “Representative”) an aggregate of 12,567,610 shares (the “Firm Shares”) of the common stock, par value $0.01 per share, of the Company (“Common Stock”), 22,214,990 Prefunded Warrants (as defined below), and 34,782,600 Firm Common Warrants (as defined below). The Company also proposes to sell to the Underwriters, at the option of the Underwriters, up to an additional 5,217,390 shares of Common Stock (the “Option Shares”) and up to an additional 5,217,390 Option Common Warrants (the “Option Common Warrants”) (which Option Common Warrants shall be in the same form as the Firm Common Warrants). The Firm Shares and the Option Shares are hereinafter referred to collectively as the “Shares”, and the Shares, the Prefunded Warrants and the Common Warrants are hereinafter referred to collectively as the “Offered Securities”, and the Offered Securities and the Warrant Shares (as defined below) are hereinafter referred to collectively as the “Securities”. For purposes herein, “Firm Common Warrants” means, collectively, the Common Stock purchase warrants of the Company delivered to Underwriters in accordance with Section 2, which Common Warrants shall be exercisable immediately and have a term of exercise equal to five (5) years from the date of issuance, in the form of Exhibit B hereto; “Prefunded Warrants” means, collectively, the prefunded Common Stock purchase warrants of the Company delivered to Underwriters in accordance with Section 2, which Prefunded Warrants shall be exercisable immediately and shall not expire until exercised in full, in the form of Exhibit C hereto; “Common Warrants” means, collectively, the Firm Common Warrants and Option Common

Warrants; “Common Warrant Shares” means the shares of Common Stock issued and issuable upon exercise of the Common Warrants; “Prefunded Warrant Shares” means the shares of Common Stock issued and issuable upon exercise of the Prefunded Warrants; “Warrants” means, collectively, the Common Warrants and Prefunded Warrants; “Warrant Shares” means, collectively, the Common Warrant Shares and Prefunded Warrant Shares; and “Option Securities” means the Option Shares and the Option Common Warrants. To the extent there are no additional Underwriters listed on Schedule I other than the Representative, the term Representative as used herein shall mean ▇▇▇▇▇-▇▇▇▇▇▇ Capital Group LLC, as Underwriters, and the term Underwriter shall mean either the singular or plural as the context requires.

The Company confirms as follows its agreements with the Representative.

1. The Company represents and warrants to, and agrees with, each of the Underwriters that, as of the date hereof and as of the Closing Date and each Option Closing Date, if any:

(i) The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (File No. 333-264888), and such amendments to such registration statement as may have been required to the date of this Agreement, under the Securities Act of 1933, as amended (the “Securities Act”), and the rules and regulations (“Rules and Regulations”) of the Commission thereunder. Each part of such registration statement, at any given time, including any amendments thereto at such time, exhibits and any schedules thereto at such time, the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act at such time and the documents and information otherwise deemed to be a part thereof or included therein by Rule 430B under the Securities Act (the “Rule 430B Information”) or otherwise pursuant to the Rules and Regulations at such time, is herein called the “Registration Statement.” The Registration Statement at the time it originally became effective is herein called the “Initial Registration Statement.” Any registration statement filed by the Company pursuant to Rule 462(b) under the Securities Act is called the “Rule 462(b) Registration Statement” and, from and after the date and time of filing of the Rule 462(b) Registration Statement, the term “Registration Statement” shall include any Rule 462(b) Registration Statement. “Testing-the-Waters Communication” means any oral or written communication with potential investors undertaken in reliance on Section 5(d) of, or Rule 163B under, the Securities Act. “Written Testing-the-Waters Communication” means any Testing-the-Waters Communication that is a written communication within the meaning of Rule 405 under the Securities Act;

The prospectus in the form in which it appeared in the Initial Registration Statement is herein called the “Base Prospectus.” Each preliminary prospectus supplement to the Base Prospectus (including the Base Prospectus as so supplemented) that described the Securities and the offering thereof, that omitted the Rule 430B Information and that was used prior to the filing of the final prospectus supplement referred to in the following sentence is herein called a “Preliminary Prospectus.” Promptly after execution and delivery of this Agreement, the Company will prepare and file with the Commission a final prospectus supplement to the Base Prospectus relating to the Securities and the offering thereof in accordance with the provisions of Rule 430B and Rule 424(b) of the Rules and Regulations. Such final supplemental form of

prospectus (including the Base Prospectus as so supplemented), in the form filed with the Commission pursuant to Rule 424(b) under the Securities Act is herein called the “Prospectus.” Any “issuer free writing prospectus” as defined in Rule 433 under the Securities Act relating to the Securities is hereinafter called an “Issuer Free Writing Prospectus.” “Statutory Prospectus” means the Base Prospectus, as amended and supplemented immediately prior to the Applicable Time, including (i) any document incorporated by reference therein, (ii) any Rule 430B Information contained in a form of prospectus that is deemed retroactively to be a part of the Registration Statement, as of the actual time that form of prospectus is filed with the Commission pursuant to Rule 424(b) under the Securities Act, and (iii) any prospectus supplement deemed to be a part thereof, including the final prospectus supplement dated the date hereof. Any reference herein to the Base Prospectus, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act as of the date of such prospectus;

For purposes of this Agreement, all references to the Registration Statement, any Rule 462(b) Registration Statement, the Base Prospectus, any Preliminary Prospectus, the Prospectus or any amendment or supplement to any of the foregoing shall be deemed to include the copy filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System or any successor system thereto (“▇▇▇▇▇”). All references in this Agreement to financial statements and schedules and other information that is “described,” “contained,” “included” or “stated” in the Registration Statement, the Base Prospectus, any Preliminary Prospectus or the Prospectus (or other references of like import) shall be deemed to mean and include all such financial statements and schedules and other information that is incorporated by reference in or otherwise deemed by the Securities Act to be a part of or included in the Registration Statement, the Base Prospectus, any Preliminary Prospectus, or the Prospectus, as the case may be. All references in this Agreement to amendments or supplements to the Registration Statement, the Base Prospectus, any Preliminary Prospectus, or the Prospectus shall be deemed to mean and include the subsequent filing of any document under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and which is deemed to be incorporated by reference therein or otherwise deemed by the Rules and Regulations to be a part thereof;

The Initial Registration Statement was declared effective by the Commission under the Securities Act on May 27, 2022. At the time of the filing of (1) the Initial Registration Statement and (2) the Company’s annual report on Form 10-K for the year ended December 31, 2021 (the “Annual Report on Form 10-K”) with the Commission, and as of the date hereof, the conditions for use of Form S-3, set forth in the General Instructions thereto, including General Instruction I.B.1, were and have been satisfied. The Company has complied, to the Commission’s satisfaction, with all requests of the Commission for additional or supplemental information. No other document with respect to the Initial Registration Statement has heretofore been filed with the Commission other than such documents as have been subsequently incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act and any Rule 430B Information. No stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto or the Rule 462(b) Registration

Statement, if any, has been issued, and no proceeding for that purpose has been initiated or threatened by the Commission;

(ii) (1) Each part of the Registration Statement, any Rule 462(b) Registration Statement, and any post-effective amendments thereto, at the time that such part became effective (including each deemed effective date with respect to the Underwriters pursuant to Rule 430B or otherwise under the Securities Act), and at the Closing Date (as defined herein) (and, if any Option Securities are purchased, at each Option Closing Date) (as defined herein)), complied and will comply in all material respects with the requirements of the Securities Act, the Rules and Regulations and the Exchange Act (with respect to the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act) and did not and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading, and (2) the Prospectus, as amended or supplemented, as of its date, and at the Closing Date (and, if any Option Securities are purchased, at each Option Closing Date), did not and will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the representations and warranties in clauses (1) and (2) above shall not apply to statements in or omissions from the Registration Statement, any Rule 462(b) Registration Statement, or any post-effective amendment thereto, or the Prospectus made in reliance upon and in conformity with information furnished to the Company in writing by any Underwriter through the Representative expressly for use therein, it being understood and agreed that the only such information provided by any Underwriter is that described as such in Section 9(b) hereof;

(iii) For the purposes of this Agreement, the “Applicable Time” is 7:00 A.M. (Eastern time) on the date of this Agreement. The Disclosure Package (as defined below) as of the Applicable Time complied in all material respects with the requirements of the Securities Act and the Rules and Regulations and did not include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the preceding sentence shall not apply to statements in or omissions from the Disclosure Package made in reliance upon and in conformity with information furnished to the Company in writing by any Underwriter through the Representative expressly for use therein, it being understood and agreed that the only such information provided by any Underwriter is that described as such in Section 9(b) hereof. Neither (1) any Issuer Free Writing Prospectus issued at or prior to the Applicable Time and set forth on Schedule II thereto, the Statutory Prospectus at the Applicable Time and the information set forth on Schedule III at the Applicable Time, all considered together (collectively, the “Disclosure Package”), nor (2) any individual Issuer Free Writing Prospectus, when considered together with the Disclosure Package, includes or included as of the Applicable Time, any untrue statement of a material fact or omits or omitted as of the Applicable Time to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the representations and warranties in clauses (1) and (2) above shall not apply to statements in or omissions from any Statutory Prospectus or any Issuer Free Writing Prospectus made in reliance upon and in conformity with information furnished to the Company in writing by any Underwriter through

the Representative expressly for use therein, it being understood and agreed that the only such information provided by any Underwriter is that described as such in Section 9(b) hereof;

Each Issuer Free Writing Prospectus, as of its issue date and at the Closing Date (as defined herein) (and, if any Option Securities are purchased, at each Option Closing Date) (as defined herein)), did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, any Statutory Prospectus or the Prospectus; provided that the foregoing sentence shall not apply to statements in or omissions from any Issuer Free Writing Prospectus made in reliance upon and in conformity with information furnished to the Company in writing by any Underwriter through the Representative expressly for use therein, it being understood and agreed that the only such information provided by any Underwriter is that described as such in Section 9(b) hereof;

(iv) The Company has filed a registration statement pursuant to the Exchange Act to register the Common Stock, and such registration statement has been declared effective. At the time of filing the Initial Registration Statement and at the time of filing of the Company’s Annual Report on Form 10-K, the Company was not and is not an “ineligible issuer,” as defined under Rule 405 under the Securities Act; the Common Stock is included or approved for listing on the NASDAQ Global Select Market and the Company has taken no action designed to, or likely to have the effect of, terminating the registration of the Common Stock under the Exchange Act or delisting the Common Stock from the NASDAQ Global Select Market nor has the Company received any notification that the Commission or the NASDAQ Global Select Market is contemplating terminating such registration or listing. The Company has complied in all material respects with the applicable requirements of the NASDAQ Global Select Market for maintenance of inclusion of the Common Stock thereon. The Company has submitted a listing of additional shares notification form to NASDAQ, Inc. to include the Shares and Warrant Shares on the NASDAQ Global Select Market. Except as previously disclosed to counsel for the Underwriters or as set forth in the Disclosure Package and the Prospectus, there are no affiliations with members of FINRA among the Company’s officers or directors or, to the knowledge of the Company, any five percent (5%) or greater stockholders of the Company, any beneficial owner of the Company’s capital stock or subordinated debt who, together with their associated persons and affiliates, hold in the aggregate 10% or more of such capital stock or subordinated debt, or any beneficial owner of the Company’s unregistered equity securities that were acquired during the 180-day period immediately preceding the initial filing date of the Registration Statement through the offering of the Offered Securities. The Company acknowledges that the Underwriters may engage in passive market making transactions in the shares of Common Stock on the NASDAQ Global Select Market in accordance with Regulation M under the Exchange Act;

(v) The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Delaware, with power and authority (corporate and other) to own its properties and conduct its business as described in the Registration Statement, the Disclosure Package and the Prospectus and to enter into and perform its obligations under this Agreement and the Warrants, and has been duly qualified as a foreign corporation for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns or leases properties or conducts any business so as to require

such qualification, except where the failure so to qualify or be in good standing would not have a material adverse effect on the Company and its subsidiaries, considered as one enterprise;

(vi) Each subsidiary of the Company (each a “Subsidiary”) has been duly incorporated (or organized) and is validly existing as a corporation (or other organization) in good standing under the laws of the jurisdiction of its incorporation (or organization), with power and authority to own its properties and conduct its business as described in the Registration Statement, the Disclosure Package and the Prospectus, and has been duly qualified as a foreign corporation (or other organization) for the transaction of business and is in good standing under the laws of each other jurisdiction in which it owns or leases properties or conducts any business so as to require such qualification, except where the failure so to qualify or be in good standing would not have a material adverse effect on the Company and the Subsidiaries, considered as one enterprise; all of the issued and outstanding capital stock (or other ownership interests) of each Subsidiary owned by the Company has been duly and validly authorized and issued, is fully paid and non-assessable and, except as described in the Registration Statement, the Disclosure Package and the Prospectus, is owned by the Company, directly or through Subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity;

(vii) The Company has an authorized capitalization as set forth in the Registration Statement, the Disclosure Package and the Prospectus, and all of the issued and outstanding shares of capital stock of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and conform to the descriptions thereof contained in the Registration Statement, the Disclosure Package and the Prospectus; and none of the issued and outstanding shares of capital stock of the Company are subject to any preemptive or similar rights;

(viii) The Shares have been duly and validly authorized and, when issued and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, will be duly and validly issued and fully paid and non-assessable and will conform to the descriptions thereof contained in the Registration Statement, the Disclosure Package and the Prospectus; and the issuance of such Shares is not subject to any preemptive or similar rights; the Warrants have been duly and validly authorized and, when issued and delivered to and paid for by the Underwriters in accordance with the terms of this Agreement, will be duly and validly issued and will conform to the descriptions thereof contained in the Registration Statement, the Disclosure Package and the Prospectus and the issuance of such Warrants is not subject to any preemptive or similar rights; the Warrant Shares have been duly authorized and, when issued in accordance with the terms of the Warrants, will be duly and validly issued and fully paid and non-assessable and will conform to the descriptions thereof contained in the Registration Statement, the Disclosure Package and the Prospectus and the issuance of such Warrant Shares is not subject to any preemptive or similar rights; the Company has reserved from its duly authorized capital stock the maximum number of shares of Common Stock issuable pursuant to this Agreement and pursuant to the Warrants;

(ix) This Agreement and the Warrants have been duly authorized, executed and delivered by the Company and constitute the valid and binding

obligation of the Company enforceable against the Company in accordance with their respective terms;

(x) The issue and sale of the Securities, the execution of this Agreement by the Company and the compliance by the Company with all of the provisions of this Agreement and the Warrants and the consummation of the transactions herein contemplated will not (A) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of the Subsidiaries is a party or by which the Company or any of the Subsidiaries is bound or to which any of the property or assets of the Company or any of the Subsidiaries is subject, (B) result in any violation of the provisions of the certificate or articles of incorporation or by-laws (or other organization documents) of the Company or any of the Subsidiaries or (C) result in the violation of any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of the Subsidiaries or any of their properties, except in the case of clause (A) as would not, individually or in the aggregate, reasonably be expected to result in a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise; and no consent, approval, authorization, order, registration or qualification of or with any such court or governmental agency or body is required for the issue and sale of the Securities or the consummation by the Company of the transactions contemplated by this Agreement and the Warrants, except the registration under the Securities Act of the Securities and such consents, approvals, authorizations, registrations or qualifications as may be required by NASDAQ Inc., FINRA or under state securities or Blue Sky laws in connection with the purchase and distribution of the Offered Securities by the Underwriters;

(xi) KPMG LLP, who have certified certain financial statements of the Company and the Subsidiaries are independent public accountants as required by the Securities Act and the Rules and Regulations. The financial statements of the Company and the Subsidiaries, together with related schedules and notes, included or incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus comply in all material respects with the requirements of the Securities Act and present fairly in all material respects the consolidated financial position, results of operations and changes in financial position of the Company and the Subsidiaries on the basis stated in the Registration Statement at the respective dates or for the respective periods to which they apply; such statements and related schedules and notes have been prepared in accordance with generally accepted accounting principles consistently applied throughout the periods involved, except as disclosed therein; and the selected financial data and the summary financial data included or incorporated by reference in the Registration Statement, the Disclosure Package or the Prospectus present fairly the information shown therein and have been compiled on a basis consistent with that of the financial statements included in the Registration Statement. The pro forma financial information and statements of the Company and the Subsidiaries and the related notes thereto included or incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus present fairly in all material respects the information shown therein, have been prepared in accordance with the Commission’s rules and guidelines with respect to pro forma financial statements and have been properly compiled on the bases described therein, and the

assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions and circumstances referred to therein. The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus fairly presents the information called for in all material respects and has been prepared in accordance with the Commission’s rules and guidelines applicable thereto;

(xii) Neither the Company nor any Subsidiary has sustained since the date of the latest audited financial statements included or incorporated by reference in the Disclosure Package any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Disclosure Package; and, since the respective dates as of which information is given in the Registration Statement and the Disclosure Package, (1) there has not been any change in the capital stock (other than the issuance of shares of Common Stock upon the exercise of stock options described as outstanding in, or the grant of options, restricted stock unit awards or other equity-based awards under the Company’s existing equity incentive plans described in, the Disclosure Package) or long-term debt of the Company or any of the Subsidiaries, other than the Deerfield Loan (as defined below), (2) there has not been any material adverse change, or any development that would reasonably be expected to result in a prospective material adverse change, in or affecting the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise, (3) there have been no transactions entered into by, and no obligations or liabilities, contingent or otherwise, incurred by the Company or any of the Subsidiaries, whether or not in the ordinary course of business, which are material to the Company and the Subsidiaries, considered as one enterprise or (4) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock, except, in each case, as set forth or contemplated in the Disclosure Package;

(xiii) Neither the Company nor any of the Subsidiaries is (1) in violation of its certificate or articles of incorporation or bylaws (or other organization documents) or (2) in violation of any law, ordinance, administrative or governmental rule or regulation applicable to the Company or any of the Subsidiaries, or (3) in violation of any decree of any court or governmental agency or body having jurisdiction over the Company or any of the Subsidiaries, or (4) in default in the performance of any obligation, agreement or condition contained in any bond, debenture, note or any other evidence of indebtedness or in any agreement, indenture, lease or other instrument to which the Company or any of the Subsidiaries is a party or by which any of them or any of their respective properties may be bound, except, in the case of clauses (2), (3) and (4), where any such violation or default, individually or in the aggregate, would not have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise;

(xiv) Each of the Company and each Subsidiary has good and marketable title to all real and personal property owned by it, in each case free and clear of all liens, encumbrances and defects except such as are described in the Registration Statement, the

Disclosure Package or the Prospectus or such as do not materially affect the value of such real and personal property and do not interfere with the use made and proposed to be made of such real and personal property by the Company or any Subsidiary; and any real property and buildings and personal property held under lease by the Company or any Subsidiary are held under valid, subsisting and enforceable leases with such exceptions as are not material and do not interfere with the use made and proposed to be made of such real property and buildings and personal property by the Company or any Subsidiary;

(xv) Other than as set forth in the Registration Statement, the Disclosure Package and the Prospectus, there are no legal or governmental proceedings pending to which the Company or any of the Subsidiaries is a party or of which any property of the Company or any of the Subsidiaries is the subject which, if determined adversely to the Company or the Subsidiary, individually or in the aggregate, would have or may reasonably be expected to have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise, or would prevent or impair the consummation of the transactions contemplated by this Agreement, or which are required to be described in the Registration Statement or the Disclosure Package; and, to the best of the Company’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or others;

(xvi) The Company and the Subsidiaries possess all permits, licenses, approvals, consents and other authorizations (collectively, “Permits”) issued by the appropriate federal, state, local or foreign regulatory agencies or bodies necessary to conduct the businesses now operated by them, except where the failure to possess any such permit, license, approval, consent or other authorization would not, individually or in the aggregate, have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise; the Company and the Subsidiaries are in compliance with the terms and conditions of all such Permits and all of the Permits are valid and in full force and effect, except, in each case, where the failure so to comply or where the invalidity of such Permits or the failure of such Permits to be in full force and effect, individually or in the aggregate, would not have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise; and neither the Company nor any Subsidiary has received any notice of proceedings relating to the revocation or material modification of any such Permits;

(xvii) The Company and the Subsidiaries own, possess or have rights to all Intellectual Property (as defined below) necessary for the conduct of their business as now conducted or as described in the Registration Statement, the Disclosure Package and the Prospectus to be conducted, except as such failure to own, possess or have such rights would not, individually or in the aggregate, reasonably be expected to result in a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise. Furthermore, (A) to the knowledge of the Company, there is no infringement, misappropriation or violation by third parties of any such Intellectual Property, except as such infringement, misappropriation or violation that would not, individually or in the aggregate, reasonably be

expected to result in a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise; (B) there is no pending or, to the knowledge of the Company, threatened, action, suit, proceeding or claim by others challenging the Company’s or any Subsidiary’s rights in or to any such Intellectual Property, and the Company and each Subsidiary is unaware of any facts which would form a reasonable basis for any such claim; (C) the Intellectual Property owned by the Company and the Subsidiaries, and the Intellectual Property licensed to the Company and the Subsidiaries, has not been adjudged invalid or unenforceable, in whole or in part, and there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others challenging the validity or scope of any such Intellectual Property, and the Company and each Subsidiary is unaware of any facts which would form a reasonable basis for any such claim; (D) there is no pending or, to the knowledge of the Company, threatened action, suit, proceeding or claim by others that the Company or any Subsidiary infringes, misappropriates or otherwise violates any Intellectual Property or other proprietary rights of others, except as would not, individually or in the aggregate, reasonably be expected to result in a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise, and the Company and each Subsidiary has not received any written notice of such claim and the Company and each Subsidiary is unaware of any other fact which would form a reasonable basis for any such claim; and (E) except as disclosed in the Registration Statement, the Disclosure Package and the Prospectus, to the knowledge of the Company, no employee of the Company or the Subsidiaries is in or has ever been in violation of any term of any employment contract, patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, nondisclosure agreement or any restrictive covenant to or with a former employer where the basis of such violation relates to such employee’s employment with the Company or any Subsidiary or actions undertaken by the employee while employed with the Company or any Subsidiary, except as such violation would not result in a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise. “Intellectual Property” shall mean all patents, patent applications, trade and service marks, trade and service mark registrations, trade names, copyrights, licenses, inventions, trade secrets, domain names, technology, know-how and other intellectual property;

(xviii) Except as described in the Registration Statement, the Disclosure Package and the Prospectus, (A) the Company has no knowledge of any material security breach or incident, unauthorized access or disclosure, or other compromise of or relating to the Company’s and its subsidiaries’ information technology and computer systems, networks, hardware, software, data and databases (including the data and information of its customers, employees, suppliers, vendors and any third party data maintained, processed or stored by or on behalf of the Company and/or its subsidiaries) (collectively, “IT Systems and Data”); (B) the Company has not been notified of, and has no knowledge of any event or condition that would reasonably be expected to result in, any material security breach or incident, unauthorized access or disclosure or other compromise to the IT Systems and Data; (C) the Company has implemented appropriate controls, policies, procedures, and technological safeguards to maintain and protect the integrity, continuous operation, redundancy and security of its IT Systems and

Data reasonably consistent with industry standards and practices, or as required by applicable regulatory standards and has complied in all material respects, and presently is in compliance in all material respects, with all applicable laws or statutes and all applicable judgments, orders, rules and regulations of any governmental agency, internal policies and contractual obligations relating to the privacy and security of IT Systems and Data and to the protection of such IT Systems and Data from unauthorized use, access, misappropriation or modification; and (D) the Company has implemented backup and disaster recovery technology consistent with industry standards and practices.

(xix) No material labor dispute with the employees of the Company or the Subsidiaries exists, or, to the knowledge of the Company, is imminent. The Company is not aware of any existing or imminent labor disturbance by the employees of any of its or any Subsidiary’s principal suppliers, manufacturers, customers or contractors, which, individually or in the aggregate, may reasonably be expected to result in a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise;

(xx) The Company and the Subsidiaries are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as are prudent and customary in the businesses in which they are engaged; neither the Company nor any Subsidiary has been refused any insurance coverage sought or applied for; and the Company has no reason to believe that either it or any Subsidiary will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not have a material adverse effect on the Company and the Subsidiaries, considered as one enterprise;

(xxi) The Company and each of its Subsidiaries have made and keep books, records and accounts, which, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the Company and its Subsidiaries. The Company maintains a system of internal accounting controls sufficient to provide reasonable assurance that (1) transactions are executed in accordance with management’s general or specific authorizations; (2) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain accountability for assets; (3) access to assets is permitted only in accordance with management’s general or specific authorization; (4) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences; and (5) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus is in conformity with generally accepted accounting principles and is updated as necessary to comply in all material respects with the requirements of the Securities Act and the Commission’s rules and guidelines applicable thereto and present fairly the consolidated financial position, results of operations and changes in financial position of the Company and the Subsidiaries on the basis stated at the respective dates or for the respective periods to which they apply;

(xxii) Since the date of the latest audited financial statements included or incorporated by reference in the Registration Statement, the Disclosure Package and the Prospectus, and except as disclosed therein, (a) the Company has not been advised of (1) any significant deficiencies in the design or operation of internal controls that could adversely affect the ability of the Company and each of its Subsidiaries to record, process, summarize and report financial data, or any material weaknesses in internal controls and (2) any fraud, whether or not material, that involves management or other employees who have a significant role in the internal controls of the Company and each of its Subsidiaries, and (b) since that date, there has been no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting;

(xxiii) The Company maintains disclosure controls and procedures (as such term is defined in Rule 13a-15 (e) of the Exchange Act) that comply with the requirements of the Exchange Act; such disclosure controls and procedures are effective;

(xxiv) All United States federal income tax returns of the Company and the Subsidiaries required by law to be filed have been timely filed and all taxes shown by such returns or otherwise assessed, which are due and payable, have been paid, except assessments against which appeals have been or will be promptly taken and as to which adequate reserves have been provided in accordance with GAAP. The Company and the Subsidiaries have timely filed all other tax returns that are required to have been filed by them pursuant to applicable foreign, state, local or other law, and have paid all taxes due and payable pursuant to such returns or pursuant to any assessment received by the Company or any Subsidiary except for such taxes, if any, as are being contested in good faith by appropriate proceedings diligently conducted and as to which adequate reserves have been provided in accordance with GAAP. The charges, accruals and reserves on the books of the Company and the Subsidiaries in respect of any tax liability for any years not finally determined are adequate to meet any assessments or re-assessments for additional tax for any years not finally determined;

(xxv) There are no statutes, regulations, documents or contracts of a character required to be described in the Registration Statement, the Disclosure Package or the Prospectus or to be filed as an exhibit to the Registration Statement which are not described or filed as required;

(xxvi) Neither the Company nor any of the Subsidiaries is in violation of any statute or any rule, regulation, decision or order of any governmental agency or body or any court, domestic or foreign, relating to the use, production, disposal or release of hazardous or toxic substances or relating to the protection or restoration of the environment or human exposure to hazardous or toxic substances (collectively, “environmental laws”), owns or operates any real property contaminated with any substance that is subject to any environmental laws, is liable for any off-site disposal or contamination pursuant to any environmental laws, or is subject to any claim relating to any environmental laws, which violation, contamination, liability or claim, individually or in the aggregate, would have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or

results of operations of the Company and the Subsidiaries, considered as one enterprise; and the Company is not aware of any pending investigation which might lead to such a claim;

(xxvii) Each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), that is maintained, administered or contributed to by the Company or any Subsidiary for employees or former employees of the Company and its affiliates has been maintained in compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to ERISA and the Internal Revenue Code of 1986, as amended (the “Code”), except to the extent that failure to so comply, individually or in the aggregate, would not have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise. No prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code has occurred with respect to any such plan excluding transactions effected pursuant to a statutory or administrative exemption;

(xxviii) The Company or any of its Subsidiaries, or any director, officer, agent, employee or other person associated with or acting on behalf of the Company or any of its Subsidiaries, has not violated, nor will their participation in the offering violate, and the Company has instituted and maintains policies and procedures designed to ensure continued compliance with, each of the following laws: (A) anti-bribery laws, including but not limited to, any applicable law, rule, or regulation of any locality, including but not limited to any law, rule, or regulation promulgated to implement the OECD Convention on Combating Bribery of Foreign Public Officials in International Business Transactions, signed December 17, 1997, including the U.S. Foreign Corrupt Practices Act of 1977, as amended, the U.K. ▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, or any other law, rule or regulation of similar purposes and scope or (B) anti-money laundering laws, including but not limited to, applicable federal, state, international, foreign or other laws, regulations or government guidance regarding anti-money laundering, including, without limitation, Title 18 US. Code section 1956 and 1957, the Patriot Act, the Bank Secrecy Act, and international anti-money laundering principles or procedures by an intergovernmental group or organization, such as the Financial Action Task Force on Money Laundering, of which the United States is a member and with which designation the United States representative to the group or organization continues to concur, all as amended, and any Executive order, directive, or regulation pursuant to the authority of any of the foregoing, or any orders or licenses issued thereunder. Neither the Company, nor any of its directors, officers or employees, nor, to the Company’s knowledge, any agent, affiliate or representative of the Company, is an individual or entity that is, or is owned or controlled by an individual or entity that is: (1) the subject of any sanctions administered or enforced by the U.S. Department of Treasury’s Office of Foreign Assets Control, the United Nations Security Council, the European Union, Her Majesty’s Treasury, or other relevant sanctions authority (collectively, “Sanctions”), nor (2) located, organized or resident in a country or territory that is the subject of Sanctions (including, without limitation, Crimea, Cuba, Iran, North Korea, and Syria). The Company will not, directly or indirectly, use the proceeds of the offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other individual or entity: (1) to fund or facilitate any activities or business of or with any individual or entity or in any country or territory that, at the time of such funding or facilitation, is the subject of Sanctions; or (2) in any

other manner that will result in a violation of Sanctions by any individual or entity (including any individual or entity participating in the offering, whether as underwriter, advisor, investor or otherwise). For the past five years, the Company has not knowingly engaged in, and is not now knowingly engaged in, any dealings or transactions with any individual or entity, or in any country or territory, that at the time of the dealing or transaction is or was the subject of Sanctions;

(xxix) There is and has been no failure on the part of the Company or any of the Company’s directors or officers, in their capacities as such, to comply with any provision of the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act of 2002 and the rules and regulations promulgated in connection therewith, including Section 402 related to loans and Sections 302 and 906 related to certifications;

(xxx) No person has the right to require the Company or any of its subsidiaries to register any securities for sale under the Securities Act by reason of the filing of the Registration Statement with the Commission or the issuance and sale of the Securities;

(xxxi) The Company is not and, after giving effect to the offering and sale of the Offered Securities as contemplated herein and the application of the net proceeds therefrom as described in the Registration Statement, the Disclosure Package and the Prospectus, will not be an “investment company”, as such term is defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”);

(xxxii) The Company has not distributed and, prior to the later to occur of the Closing Date (as defined in Section 4 hereof) and completion of distribution of the Offered Securities, will not distribute any offering materials in connection with the offering and sale of the Offered Securities, other than the Preliminary Prospectus, the Prospectus and, subject to compliance with Section 6 hereof, any Issuer Free Writing Prospectus; and the Company has not taken and will not take, directly or indirectly, any action designed to cause or result in, or which constitutes or might reasonably be expected to constitute, the stabilization or manipulation of the price of any security of the Company to facilitate the sale of the Offered Securities. The Company (a) has not alone engaged in any Testing-the-Waters Communication other than Testing-the-Waters Communications with the consent of the Representative (x) with entities that are qualified institutional buyers (“QIBs”) within the meaning of Rule 144A under the Securities Act or institutions that are accredited investors within the meaning of Rule 501(a)(1), (a)(2), (a)(3), (a)(7) or (a)(8) under the Securities Act (“IAIs”) and otherwise in compliance with the requirements of Section 5(d) of the Securities Act or (y) with entities that the Company reasonably believed to be QIBs or IAIs and otherwise in compliance with the requirements of Rule 163B under the Securities Act and (b) has not authorized anyone other than the Representative to engage in Testing-the-Waters Communications. The Company reconfirms that the Representative have been authorized to act on its behalf in undertaking Testing-the-Waters Communications. The Company has not distributed any Written Testing-the-Waters Communications;

(xxxiii) The statistical and market and industry-related data included in the Registration Statement, the Disclosure Package and the Prospectus are based on or derived from

sources which the Company believes to be reliable and accurate or represent the Company’s good faith estimates that are made on the basis of data derived from such sources, and the Company has obtained the written consent to the use of such data from sources to the extent required;

(xxxiv) [reserved];

(xxxv) Any certificate signed by any officer of the Company delivered to the Underwriters or to counsel for the Underwriters shall be deemed a representation and warranty by the Company to the Underwriters as to the matters covered thereby;

(xxxvi) Except as described in the Registration Statement, the Disclosure Package and the Prospectus, the Company: (i) has not received any unresolved U.S. Food and Drug Administration (“FDA”) Form 483 or other Governmental Authority notice of inspectional observations, notice of adverse filing, warning letter, untitled letter or other correspondence or notice from the FDA, or any other court or arbitrator or federal, state, local or foreign governmental or regulatory authority, alleging or asserting noncompliance with the Federal Food, Drug and Cosmetic Act (21 U.S.C. § 301 et seq.), or received any requests or requirements to make changes to the Company products by the FDA or any other Governmental Authority; (ii) is and has been in material compliance with applicable health care laws, including without limitation, the Federal Food, Drug and Cosmetic Act (21 U.S.C. § 301 et seq.), the federal Anti-kickback Statute (42 U.S.C. § 1320a-7b(b)), the civil False Claims Act (31 U.S.C. § 3729 et seq.), the administrative False Claims Law (42 U.S.C. § 1320a-7b(a)), the Civil Monetary Penalties Law (42 U.S.C. § 1320a-7a), the Health Insurance Portability and Accountability Act of 1996 (42 U.S.C. § 1320d et seq.), as amended by the Health Information Technology for Economic and Clinical Health Act of 2009 (collectively, “HIPAA”), the exclusion laws (42 U.S.C. § 1320a-7), the Physician Payments Sunshine Act (42 U.S.C. § 1320a-7h), all criminal laws relating to health care fraud and abuse, including but not limited to 18 U.S.C. Sections 286 and 287, and the health care fraud criminal provisions under HIPAA, Medicare (Title XVIII of the Social Security Act), Medicaid (Title XIX of the Social Security Act), and the regulations promulgated pursuant to such laws, and comparable state laws, and all other local, state, federal, national, supranational and foreign laws, manual provisions, policies and administrative guidance relating to the regulation of the Company (collectively, the “Health Care Laws”); (iii) possesses all licenses, certificates, approvals, clearances, authorizations, permits and supplements or amendments thereto required by any such Health Care Laws to carry on its businesses as now or proposed to be conducted (collectively, the “Authorizations”) and such Authorizations are valid and in full force and effect and the Company is not in material violation of any term of any such Authorizations; (iv) has not received notice of any ongoing claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any Governmental Authority or third party alleging any material violation of any Health Care Laws or Authorizations and has no knowledge that any such Governmental Authority or third party is considering any such claim, litigation, arbitration, action, suit, investigation or proceeding; (v) has not received notice that any Governmental Authority has taken, is taking or intends to take action to limit, suspend, modify or revoke any Authorizations and has no knowledge that any such Governmental Authority is considering such action; (vi) has filed, obtained, maintained or submitted all material reports, documents, forms, notices, applications,

records, claims, submissions and supplements or amendments thereto as required by any Health Care Laws or Authorizations and all such reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments were complete, correct and not misleading on the date filed (or were corrected or supplemented by a subsequent submission if required by law); (vii) has not, either voluntarily or involuntarily, initiated, conducted, or issued or caused to be initiated, conducted or issued, any recall, market withdrawal or replacement, safety alert, post sale warning, “dear doctor” letter, or other notice or action relating to the alleged lack of safety, efficacy or regulatory compliance of any product or any alleged product defect or violation and, to the Company’s knowledge, no third party has initiated or conducted any such notice or action and there are no facts which are reasonably likely to cause, and the Company has not received any written notice from the FDA or any other regulatory agency regarding, a material recall, market withdrawal or replacement of any Company product sold or intended to be sold by the Company, a material change in the marketing classification or a material adverse change in the labeling of any such Company products, or a termination or suspension of the manufacturing, marketing, or distribution of such Company products; (viii) is not a party to any corporate integrity agreement, deferred prosecution agreement, monitoring agreement, consent decree, settlement order, or similar agreements, or has any reporting obligations pursuant to any such agreement, plan or correction or other remedial measure entered into with any Governmental Authority; (ix) has not, nor has any officer, director, employee, or, to the knowledge of the Company, any agent or distributor of the Company, made an untrue statement of a material fact or a fraudulent statement to the FDA or any other Governmental Authority, failed to disclose a material fact required to be disclosed to the FDA or any other Governmental Authority, or committed an act, made a statement, or failed to make a statement, in each such case, related to the business of the Company that, at the time such disclosure was made, would reasonably be expected to provide a basis for the FDA to invoke its policy respecting “Fraud, Untrue Statements of Material Facts, Bribery, and Illegal Gratuities”, set forth in 56 Fed. Reg. 46191 (September 10, 1991) or for the FDA or any other Governmental Authority to invoke any similar policy, except for any act or statement or failure to make a statement that, individually or in the aggregate, has not had and would not reasonably be expected to have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise; (x) has not, nor has any officer, director, employee, or, to the knowledge of the Company, any agent or distributor of the Company, been debarred or convicted of any crime or engaged in any conduct for which debarment is mandated by 21 U.S.C. § 335a(a) or any similar Law or authorized by 21 U.S.C. § 335a(b) or any similar Law applicable in other jurisdictions in which material quantities of any of the Company products or Company product candidates are sold or intended by the Company to be sold; and (xi) none of the Company or its officers, directors, or employees, or, to the knowledge of the Company, its agents or contractors, has been or is currently excluded from participation in the Medicare and Medicaid programs or any other state or federal health care program;

(xxxvii) The studies, tests and preclinical and clinical trials conducted or sponsored by or, to the knowledge of the Company, conducted on behalf of, the Company as described in the Registration Statement, the Disclosure Package and the Prospectus, were and, if still pending, are, in all material respects, being conducted in accordance with applicable experimental protocols, procedures and controls pursuant to accepted professional

medical and scientific standards and all relevant applicable laws and Authorizations, including, without limitation, the Federal Food, Drug and Cosmetic Act and the rules and regulations promulgated thereunder; the descriptions of the results of such studies, tests and trials contained in the Registration Statement, the Disclosure Package and the Prospectus are accurate and complete in all material respects and fairly present the data derived from such studies, tests and trials; except to the extent disclosed in the Registration Statement, the Disclosure Package and the Prospectus, the Company has no knowledge of any studies, tests or trials the results of which the Company believes reasonably call into question the study, test or trial results described or referred to in the Registration Statement, the Disclosure Package and the Prospectus when viewed in the context in which such results are described and the clinical state of development; and the Company has not received any notices or correspondence from any Governmental Authority requiring the termination, suspension or material modification of any studies, tests or preclinical or clinical trials conducted by or on behalf of the Company;

(xxxviii) The Company (A) is in compliance, in all material respects, with any and all applicable foreign, federal, state and local laws, rules, regulations, treaties, statutes and codes promulgated by any and all Governmental Authorities (including pursuant to the Occupational Health and Safety Act) relating to the protection of human health and safety in the workplace (“Occupational Laws”); (B) has received all material permits, licenses or other approvals required of it under applicable Occupational Laws to conduct its business as currently conducted; and (C) is in compliance, in all material respects, with all terms and conditions of such permit, license or approval. No action, proceeding, revocation proceeding, writ, injunction or claim is pending or, to the Company’s knowledge, threatened against the Company relating to Occupational Laws, and the Company does not have knowledge of any facts, circumstances or developments relating to its operations or cost accounting practices that could reasonably be expected to form the basis for or give rise to such actions, suits, investigations or proceedings that would reasonably be expected to have a material adverse effect on the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise;

(xxxix) [reserved];

(xl) Except as disclosed in the Registration Statement, the Disclosure Package and the Prospectus, the Company has not granted rights to develop, manufacture, produce, assemble, distribute, license, market or sell its products to any other person and is not bound by any agreement that affects the exclusive right of the Company to develop, manufacture, produce, assemble, distribute, license, market or sell its products;

(xli) No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) included or incorporated by reference in any of the Registration Statement, the Disclosure Package or the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith. The statements and financial information (including the assumptions described herein) included in the Registration Statement, the Disclosure Package and the Prospectus under each of the headings “Prospectus Supplement Summary—Recent

Developments” (i) are within the coverage of the safe harbor for forward looking statements set forth in Section 27A of the Act, Rule 175(b) under the Securities Act or Rule 3b-6 under the Exchange Act, as applicable, (ii) were made by the Company with a reasonable basis and in good faith and reflect the Company’s good faith best estimate of the matters described therein, and (iii) have been prepared in accordance with Item 10 of Regulation S-K under the Act; the assumptions used in the preparation of such statements and financial information are reasonable; and none of the Company or its subsidiaries are aware of any business, economic or industry developments materially inconsistent with the assumptions underlying such statements and financial information;

(xlii) [reserved]; and

(xliii) The Company is, and at the time of the filing of the Registration Statement was, a “smaller reporting company,” as defined in Rule 12b-2 of the Exchange Act.

2. Subject to the terms and conditions herein set forth, the Company agrees to sell to the Underwriters, in the aggregate, (i) 12,567,610 Firm Shares, (ii) 22,214,990 Prefunded Warrants, and (iii) 34,782,600 Firm Common Warrants, and each of the Underwriters agrees to purchase from the Company (a) the number of Firm Shares as set forth opposite the name of such Underwriter in Schedule I hereto, (b) the number of Prefunded Warrants as set forth opposite the name of such Underwriter in Schedule I hereto and (c) the number of Firm Common Warrants as set forth opposite the name of such Underwriter in Schedule I hereto. The combined purchase price for one (1) Firm Share and one (1) Firm Common Warrant shall be $0.3610 (the “Combined Share Purchase Price”), which shall be allocated as $0.360905 per Firm Share (the “Share Purchase Price”) and $0.000095 per Firm Common Warrant (the “Warrant Purchase Price”). The combined purchase price for one (1) Prefunded Warrant and one (1) Firm Common Warrant shall be $0.3515 (the “Combined Prefunded Warrant Purchase Price”), which shall be allocated as $0.351405 per Prefunded Warrant (the “Prefunded Warrant Purchase Price”) and $0.000095 per Firm Common Warrant. In the event and to the extent that the Underwriters shall exercise the election to purchase Option Shares and/or Option Common Warrants as provided below, the Company agrees to sell to the Underwriters, in the aggregate, up to 5,217,390 Option Shares at the Share Purchase Price and/or up to 5,217,390 Option Common Warrants at the Warrant Purchase Price, which may be purchased in any combination of Option Shares and/or Option Common Warrants at the Share Purchase Price and/or Warrant Purchase Price, respectively, and each of the Underwriters agrees to purchase from the Company, (a) the number of Option Shares (to be adjusted by the Representative so as to eliminate fractional shares) determined by multiplying the number of Option Shares as to which such election shall have been exercised by a fraction, the numerator of which is the aggregate number of Firm Shares and Prefunded Warrants to be purchased by such Underwriter as set forth opposite the name of such Underwriter in Schedule I hereto and the denominator of which is the aggregate number of Firm Shares and Prefunded Warrants to be purchased by all of the Underwriters from the Company hereunder, and/or (b) the number of Option Common Warrants (to be adjusted by the Representative so as to eliminate fractional warrants) determined by multiplying the number of Option Common Warrants as to which such election shall have been exercised by a fraction, the numerator of which is the aggregate number of Firm Warrants to be purchased by such Underwriter as set forth opposite the name of such Underwriter in Schedule I hereto and the

denominator of which is the aggregate number of Firm Warrants to be purchased by all of the Underwriters from the Company hereunder.

The Underwriters may exercise their option to acquire Option Shares and/or Option Common Warrants in whole or in part from time to time only by written notice from the Representative to the Company, given within a period of 30 calendar days after the date of this Agreement and setting forth the aggregate number of Option Shares and/or Option Common Warrants to be purchased and the date on which such Option Shares and/or Option Common Warrants are to be delivered, as determined by the Representative but in no event earlier than the Closing Date or, unless the Representative and the Company otherwise agree in writing, earlier than two or later than ten business days after the date of such notice (unless the option is exercised on or prior to the business day prior to the Closing Date and such notice specifies that the delivery of the Option Shares and/or Option Warrants shall occur on the Closing Date).

3. It is understood that the Underwriters propose to offer the Firm Shares, Prefunded Warrants and the Firm Common Warrants for sale to the public upon the terms and conditions set forth in the Prospectus.

4. The Company will deliver the Firm Shares to the Representative through the facilities of the Depository Trust Company (“DTC”) for the accounts of the Underwriters, against payment of the purchase price therefor in Federal (same day) funds by wire transfer to the account specified by the Company at the office of ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ & Schole LLP, 1345 Avenue of the ▇▇▇▇▇▇▇▇, ▇▇▇▇ ▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, at 10:00 A.M., New York time, on October 25, 2022, or at such other time not later than seven full business days thereafter as the Representative and the Company determine, such time being herein referred to as the “Closing Date”. On the Closing Date, the Company shall deliver (i) the Prefunded Warrants to each Underwriter, in certificated form registered in the name or names and in such authorized denominations as the applicable Underwriter may request in writing at least one full Business Day prior to the Closing Date and (ii) the Firm Common Warrants to each Underwriter, in certificated form registered in the name or names and in such authorized denominations as the applicable Underwriter may request in writing at least one full Business Day prior to the Closing Date. For purposes of Rule 15c6-1 under the Exchange Act, the Closing Date (if later than the otherwise applicable settlement date) shall be the settlement date for payment of funds and delivery of securities for all the Firm Shares, Prefunded Warrants and Firm Common Warrants. Delivery of the Firm Shares will be made by credit to the accounts designated by the Representative through DTC’s full fast transfer or DWAC programs.

Each time for the delivery of and payment for the Option Shares and/or Option Common Warrants, being herein referred to as an “Option Closing Date”, which may be the Closing Date, shall be determined by the Representative as provided above. The Company will deliver the Option Shares being purchased on each Option Closing Date to the Representative through the facilities of DTC for the accounts of the Underwriters, against payment of the purchase price therefor in Federal (same day) funds by wire transfer to the account specified by the Company at the above office of ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ & Schole LLP, at 10:00 A.M., New York time on the applicable Option Closing Date. On the Option Closing Date, the Company shall deliver the Option Common Warrants to each Underwriter, in certificated form registered in the

name or names and in such authorized denominations as the applicable Underwriter may request in writing at least one full Business Day prior to the Option Closing Date. Delivery of the Option Shares will be made by credit to the accounts designated by the Representative through DTC’s full fast transfer or DWAC programs.

5. The Company covenants and agrees with each of the Underwriters as follows:

(a) The Company, subject to Section 5(b), will comply with the requirements of Rule 430B under the Securities Act, and will notify the Representative immediately, and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement shall become effective, or any supplement to the Prospectus or any amended prospectus shall have been filed, to furnish the Representative with copies thereof, and to file promptly all material required to be filed by the Company with the Commission pursuant to Rule 433(d) under the Securities Act, (ii) of the receipt of any comments from the Commission, (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or for additional information, (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of any order preventing or suspending the use of any Preliminary Prospectus, or of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes; and (v) if the Company ceases to be an Emerging Growth Company at any time prior to the later of (A) completion of the distribution of the Offered Securities within the meaning of the Securities Act and (B) completion of the 90-day restricted period referred to in Section 5(j) hereof. The Company will promptly effect the filings necessary pursuant to Rule 424(b) under the Securities Act and will take such steps as it deems necessary to ascertain promptly whether the form of prospectus transmitted for filing under Rule 424(b) was received for filing by the Commission and, in the event that it was not, it will promptly file such prospectus. The Company will make every reasonable effort to prevent the issuance of any stop order and, if any stop order is issued, to obtain the lifting thereof at the earliest possible moment.

(b) The Company will give the Representative notice of its intention to file or prepare any amendment to the Registration Statement (including any filing under Rule 462(b) under the Securities Act), or any amendment, supplement or revision to the Prospectus, or any Issuer Free Writing Prospectus, will furnish the Representative with copies of any such documents a reasonable amount of time prior to such proposed filing or use, as the case may be, and will not file or use any such document to which the Representative or counsel for the Underwriters shall reasonably object.

(c) The Company will use its best efforts to qualify the Securities for offering and sale under the securities laws of such jurisdictions as you may reasonably request and to comply with such laws so as to permit the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of the Securities, provided that nothing in this Section 5(c) shall require the Company to qualify as a foreign corporation in any jurisdiction in which it is not already so qualified, or to file a general consent to service of process in any jurisdiction.

(d) The Company has furnished or will upon request deliver to the Representative, without charge, copies of the Initial Registration Statement as originally filed, any Rule 462(b) Registration Statement, the Disclosure Package, the Prospectus, any free writing prospectus and all amendments and supplements to each (including exhibits filed therewith or incorporated by reference therein), in each case as soon as practicable and ins such quantities as the Representative may from time to time reasonably request.

(e) The Company has delivered to each Underwriter, without charge, as many written and electronic copies of each Preliminary Prospectus as such Underwriter reasonably requested, and the Company hereby consents to the use of such copies for purposes permitted by the Securities Act. The Company will furnish to each Underwriter, without charge, prior to 5:00 P.M. (Eastern time) on the business day next succeeding the date of this Agreement and from time to time thereafter during the period when the Prospectus is required to be delivered in connection with sales of the Offered Securities under the Securities Act or the Exchange Act or in lieu thereof, the notice referred to in Rule 173(a) under the Securities Act, such number of written and electronic copies of the Prospectus (as amended or supplemented) as such Underwriter may reasonably request. The Prospectus and any amendments or supplements thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

(f) The Company will comply with the Securities Act, the Rules and Regulations and the Exchange Act so as to permit the completion of the distribution of the Offered Securities as contemplated in this Agreement and in the Prospectus. If at any time when, in the opinion of counsel for the Underwriters, a prospectus is required to be delivered in connection with sales of the Offered Securities under the Securities Act or the Exchange Act (or in lieu thereof, the notice referred to in Rule 173(a) under the Securities Act), any event shall occur or condition shall exist as a result of which it is necessary, in the opinion of counsel for the Underwriters or for the Company, to amend the Registration Statement or amend or supplement the Prospectus or to file under the Exchange Act any document that would be deemed to be incorporated by referenced in the Prospectus in order that the Prospectus will not include any untrue statements of a material fact or omit to state a material fact necessary in order to make the statements therein not misleading in the light of the circumstances existing at the time it (or in lieu thereof, the notice referred to in Rule 173(a) under the Securities Act) is delivered to a purchaser, or if it shall be necessary, in the opinion of either such counsel, at any such time to amend the Registration Statement or amend or supplement the Prospectus in order to comply with the requirements of the Securities Act, the Rules and Regulations or the Exchange Act, the Company will promptly prepare and file with the Commission, subject to Section 5(b), such amendment or supplement as may be necessary to correct such statement or omission or to make the Registration Statement or the Prospectus or any document that would be deemed to be incorporated by referenced in the Prospectus in order to comply with such requirements, and the Company will furnish to the Underwriters such number of written and electronic copies of such amendment or supplement as the Underwriters may reasonably request. The Company will provide the Representative with notice of the occurrence of any event during the period specified above that may give rise to the need to amend or supplement the Registration Statement or the Prospectus as provided in the preceding sentence promptly after the occurrence of such event.

(g) The Company will make generally available (within the meaning of Section 11(a) of the Securities Act) to its security holders and to the Representative as soon as practicable, but not later than 45 days after the end of its fiscal quarter in which the first anniversary date of the effective date of the Registration Statement occurs, an earnings statement (in form complying with the provisions of Rule 158 under the Securities Act) covering a period of at least twelve consecutive months beginning after the effective date of the Registration Statement.

(h) The Company will use the net proceeds received by it from the sale of the Offered Securities in the manner specified in the Disclosure Package and the Prospectus under the heading “Use of Proceeds”.

(i) The Company will use its best efforts to effect and maintain the listing of the Common Stock (including the Shares and the Warrant Shares) on the NASDAQ Global Select Market.

(j) The Company will not, without the prior written consent of the Representative, from the date of execution of this Agreement and continuing to and including the date 90 days after the date of the Prospectus (the “Lock-Up Period”), (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock or (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise. The restrictions contained in the preceding paragraph shall not apply to (i) the Offered Securities to be sold to the Underwriters pursuant to this Agreement, (ii) any issuances of any securities pursuant to the Deerfield Loan and the transactions in connection therewith, include securities issued pursuant to that certain Exchange Agreement, dated October 12, 2022, by and between the Company and Deerfield, (iii) the issuance by the Company of shares of Common Stock upon the exercise of an option or warrant or the settlement of any other stock-based awards outstanding on the date hereof which is described in the Disclosure Package and the Prospectus, provided that such securities have not been amended since the date of this Agreement to increase the number of such securities or to decrease the exercise price, exchange price or conversion price of such securities or to extend the term of such securities, (iv) the grant by the Company of stock options or other stock-based awards (or the issuance of shares of Common Stock upon exercise thereof) to eligible participants pursuant to employee benefit or equity incentive plans of the Company described in the Disclosure Package and the Prospectus; provided that, prior to the grant of any such stock options or other stock-based awards pursuant to this clause (iv) that vest within the Lock-Up Period, each director or officer receiving such grant shall sign and deliver a lock-up agreement substantially in the form of Exhibit A hereto, (v) the securities issued in connection with any joint venture, commercial or collaborative relationship or the acquisition or license by the Company of the securities, businesses, property or other assets of another person or entity or pursuant to any employee benefit plan assumed by the Company in connection with any such acquisition, but shall not include a transaction in which the Company is issuing securities

primarily for the purpose of raising capital or to an entity whose primary business is investing in securities; provided, however, that in the case of this clause (v), the recipients thereof deliver a lock-up agreement substantially in the form of Exhibit A hereto, or (vi) the filing of a registration statement on Form S-8 with respect to the registration of securities to be offered under any employee benefit or equity incentive plans of the Company described in the Disclosure Package and the Prospectus to the Company’s employees. For purposes herein, the “Deerfield Loan” means the Company’s Amended and Restated Facility Agreement, dated October 12, 2022, by and among the Company, certain of its subsidiaries and Deerfield Partners, L.P. (“Deerfield”) and the other lenders party thereto from time to time.

(k) From the date of execution of this Agreement until the date that is twelve (12) months after the date of the Prospectus, the Company shall be prohibited from effecting or entering into an agreement to effect any issuance by the Company or any of its Subsidiaries of shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock (or a combination of units thereof) involving a Variable Rate Transaction. “Variable Rate Transaction” means a transaction in which the Company (i) issues or sells any debt or equity securities that are convertible into, exchangeable or exercisable for, or include the right to receive, additional shares of Common Stock either (A) at a conversion price, exercise price or exchange rate or other price that is based upon, and/or varies with, the trading prices of or quotations for the shares of Common Stock at any time after the initial issuance of such debt or equity securities or (B) with a conversion, exercise or exchange price that is subject to being reset at some future date after the initial issuance of such debt or equity security or upon the occurrence of specified or contingent events directly or indirectly related to the business of the Company or the market for the Common Stock or (ii) enters into, or effects a transaction under, any agreement, including, but not limited to, an equity line of credit or an “at-the-market” offering, whereby the Company may issue securities at a future determined price regardless of whether shares pursuant to such agreement have actually been issued and regardless of whether such agreement is subsequently cancelled; provided, however, that the following shall not be deemed a Variable Rate Transaction: (a) after ninety (90) days after the date of the Prospectus, the issuance of shares of Common Stock in an “at the market” offering at a sales price equal to or higher than $0.3610 (as adjusted for reverse and forward stock splits, recapitalizations and similar transactions after the date hereof) shall not be deemed a Variable Rate Transaction and (b) after one hundred and eighty (180) days after the date of the Prospectus, the issuance of shares of Common Stock in an “at the market” offering. Any Underwriter shall be entitled to obtain injunctive relief against the Company to preclude any such issuance, which remedy shall be in addition to any right to collect damages.

(l) The Company will cause to be delivered to the Representative prior to the date of this Agreement a letter, substantially in the form of Exhibit A hereto, from each individual listed on Schedule IV.

(m) The Company, during the period when the Prospectus is required to be delivered in connection with sales of the Offered Securities under the Securities Act or the Exchange Act (or in lieu thereof, the notice referred to in Rule 173(a) under the Securities Act), will file all documents required to be filed with the Commission pursuant to the Exchange Act

within the time periods required by the Exchange Act and the rules and regulations of the Commission thereunder.

(n) The Company will file with the Commission such information on Form 10-Q or Form 10-K as may be required pursuant to Rule 463 under the Securities Act.

(o) During a period of three years from the effective date of the Registration Statement, upon request of the Representative, the Company will furnish to the Representative copies of all reports or other communications (financial or other) furnished to stockholders generally, and to deliver to you (i) as soon as they are available, copies of any reports and financial statements furnished to or filed with the Commission or any national securities exchange on which any class of securities of the Company is listed, provided that the Company will be deemed to have furnished such reports and financial statements to the extent they are filed on ▇▇▇▇▇; and (ii) such additional information concerning the business and financial condition of the Company as the Representative may from time to time reasonably request (such financial statements to be on a consolidated basis to the extent the accounts of the Company and the Subsidiaries are consolidated in reports furnished to its stockholders generally or to the Commission).

(p) If the Company elects to rely upon Rule 462(b) under the Securities Act, the Company will file a Rule 462(b) Registration Statement with the Commission in compliance with Rule 462(b) by 10:00 P.M., Washington, D.C. time, on the date of this Agreement, and at the time of filing either to pay to the Commission the filing fee for the Rule 462(b) Registration Statement or to give irrevocable instructions for the payment of such fee pursuant to Rule 111(b) under the Securities Act.

(q) If so requested by the Representative, the Company shall cause to be prepared and delivered, at its expense, within one business day from the effective date of this Agreement, to the Representative an “electronic Prospectus” to be used by the Underwriters in connection with the offering and sale of the Securities. As used herein, the term “electronic Prospectus” means a form of the most recent Preliminary Prospectus, any Issuer Free Writing Prospectus or the Prospectus, and any amendment or supplement thereto, that meets each of the following conditions: (i) it shall be encoded in an electronic format, satisfactory to the Representative, that may be transmitted electronically by the Representative and the other Underwriters to offerees and purchasers of the Offered Securities, (ii) it shall disclose the same information as such paper Preliminary Prospectus, Issuer Free Writing Prospectus or the Prospectus, as the case may be; and (iii) it shall be in or convertible into a paper format or an electronic format, satisfactory to the Representative, that will allow investors to store and have continuously ready access to such Preliminary Prospectus, Issuer Free Writing Prospectus or the Prospectus at any future time, without charge to investors (other than any fee charged for subscription to the Internet generally). The Company hereby confirms that, if so requested by the Representative, it has included or will include in the Prospectus filed with the Commission an undertaking that, upon receipt of a request by an investor or his or her representative, the Company shall transmit or cause to be transmitted promptly, without charge, a paper copy of such paper Preliminary Prospectus, Issuer Free Writing Prospectus or the Prospectus to such investor or representative.

(r) The Company will promptly notify the Representative if the Company ceases to be an Emerging Growth Company at any time prior to the later of (A) completion of the distribution of Offered Securities within the meaning of the Securities Act and (B) completion of the 90-day restricted period referenced to in Section 5(j) hereof.

6. (a) The Company represents and agrees that, without the prior consent of the Representative, it has not made and will not make any offer relating to the Offered Securities that would constitute a “free writing prospectus” as defined in Rule 405 under the Securities Act; each Underwriter represents and agrees that, without the prior consent of the Company and the Representative, it has not made and will not make any offer relating to the Offered Securities that would constitute a free writing prospectus; any such free writing prospectus the use of which has been consented to by the Company and the Representative is listed on Schedule II hereto;

(b) The Company has complied and will comply with the requirements of Rule 433 under the Securities Act applicable to any Issuer Free Writing Prospectus, including timely filing with the Commission or retention where required and legending; the Company represents that it has satisfied and agrees that it will satisfy the conditions under Rule 433 under the Securities Act to avoid a requirement to file with the Commission any electronic road show; and

(c) The Company agrees that if at any time following issuance of an Issuer Free Writing Prospectus any event occurred or occurs as a result of which such Issuer Free Writing Prospectus would conflict with the information in the Registration Statement, the Disclosure Package or the Prospectus or, when considered together with the information in the Disclosure Package and other Issuer Free Writing Prospectuses, would include an untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances then prevailing, not misleading, the Company will give prompt notice thereof to the Representative and, if requested by the Representative, will prepare and furnish without charge to each Underwriter an Issuer Free Writing Prospectus or other document which will correct such conflict, statement or omission; provided, however, that this covenant shall not apply to any statements or omissions in an Issuer Free Writing Prospectus made in reliance upon and in conformity with information furnished to the Company in writing by any Underwriter through the Representative expressly for use therein, it being understood and agreed that the only such information provided by any Underwriter is that described as such in Section 9(b) hereof.

7. The Company covenants and agrees with the Underwriters that, whether or not the transactions contemplated by this Agreement are consummated, the Company will pay or cause to be paid all expenses incident to the performance of its obligations under this Agreement, including (i) the fees, disbursements and expenses of the Company’s counsel, accountants and other advisors; (ii) filing fees and all other expenses in connection with the preparation, printing and filing of the Registration Statement, each Preliminary Prospectus, any Issuer Free Writing Prospectus and the Prospectus and amendments and supplements thereto and the mailing and delivering of copies thereof to the Underwriters and dealers; (iii) the cost of printing or producing this Agreement, closing documents (including any compilations thereof) and such other documents as may be required in connection with the offering, purchase, sale and delivery

of the Offered Securities; (iv) all expenses in connection with the qualification of the Securities for offering and sale under state securities laws as provided in Section 5(c), including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection with such qualification and in connection with the Blue Sky survey, if any; (v) all fees and expenses in connection with listing the Common Stock (including the Shares and the Warrant Shares) on the NASDAQ Global Select Market; (vi) the filing fees incident to, and the reasonable fees and disbursements of counsel for the Underwriters in connection with, securing any required review by FINRA of the terms of the sale of the Offered Securities; (vii) all fees and expenses in connection with the preparation, issuance and delivery of the certificates representing the Offered Securities to the Underwriters, including any stock or other transfer taxes and any stamp or other duties payable upon the sale, issuance or delivery of the Offered Securities to the Underwriters; (viii) the cost and charges of any transfer agent or registrar; (ix) the transportation and other expenses incurred by the Company in connection with presentations to prospective purchasers of the Offered Securities; (x) up to $100,000 for the reasonable out-of-pocket accountable fees and disbursements of counsel for the Representative (including any fees and disbursements of counsel under clauses (iv) and (vi) herein) and the reasonable out-of-pocket accountable travel and related expenses and other expenses of the Representative in connection with the sale of the Offered Securities; and (xi) all other costs and expenses incident to the performance of its obligations hereunder which are not otherwise specifically provided for in this Section 7. It is understood that, subject to this Section 7 and Section 12, the Underwriters will pay all of their costs and expenses associated with the transactions contemplated hereunder, including all fees and disbursements of Representative’s counsel.

8. The obligations of the Underwriters hereunder to purchase the Offered Securities on the Closing Date or each Option Closing Date, as the case may be, are subject to the performance by the Company of its obligations hereunder and to the following additional conditions:

(a) The Prospectus shall have been filed with the Commission pursuant to Rule 424(b) under the Securities Act within the applicable time period prescribed for such filing by the Rules and Regulations and in accordance with Section 5(a); all material required to be filed by the Company pursuant to Rule 433(d) under the Securities Act shall have been filed with the Commission within the applicable time period prescribed for such filing by Rule 433 under the Securities Act; if the Company has elected to rely upon Rule 462(b) under the Securities Act, the Rule 462(b) Registration Statement shall have become effective by 10:00 P.M., Washington, D.C. time, on the date of this Agreement; no stop order suspending the effectiveness of the Registration Statement or any part thereof or any amendment thereto shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission or any state securities commission; no stop order suspending or preventing the use of the Disclosure Package, the Prospectus or any part thereof or any Issuer Free Writing Prospectus shall have been issued and no proceeding for that purpose shall have been initiated or threatened by the Commission or any state securities commission; and all requests for additional information on the part of the Commission shall have been complied with to the Representative’ reasonable satisfaction.

(b) The representations and warranties of the Company contained herein are true and correct on and as of the Closing Date or the Option Closing Date, as the case may be, as if made on and as of the Closing Date or the Option Closing Date, as the case may be, and the Company shall have complied with all agreements and all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date or the Option Closing Date, as the case may be.

(c) Subsequent to the execution and delivery of this Agreement and prior to the Closing Date or the Option Closing Date, as the case may be, there shall not have occurred any downgrading, nor shall any notice have been given of (i) any downgrading, (ii) any intended or potential downgrading or (iii) any review or possible change that does not indicate an improvement, in the rating accorded any securities of or guaranteed by the Company or any Subsidiary by any “nationally recognized statistical rating organization”, as such term is defined for purposes of Rule 436(g)(2) under the Securities Act.

(d) (i) Neither the Company nor any Subsidiary shall have sustained since the date of the latest audited financial statements included or incorporated by reference in the Disclosure Package any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, otherwise than as set forth or contemplated in the Disclosure Package, and (ii) since the respective dates as of which information is given in the Registration Statement, the Disclosure Package and the Prospectus and except as described in the Registration Statement, the Disclosure Package and the Prospectus, (1) there shall not have been any change in the capital stock or long-term debt of the Company or any Subsidiary, except pursuant to the Deerfield Loan and the transactions contemplated thereby, or (2) there shall not have been any material adverse change, or any development that would reasonably be expected to result in a prospective material adverse change, in or affecting the general affairs, business, prospects, management, financial position, stockholders’ equity or results of operations of the Company and the Subsidiaries, considered as one enterprise, the effect of which, in any such case described in clause (i) or (ii), is in the judgment of the Representative so material and adverse as to make it impracticable or inadvisable to proceed with the public offering or the delivery of the Offered Securities being delivered at such Closing Date or Option Closing Date, as the case may be, on the terms and in the manner contemplated in the Disclosure Package and the Prospectus.

(e) The Representative shall have received on and as of the Closing Date or the Option Closing Date, as the case may be, a certificate of two executive officers of the Company, at least one of whom has specific knowledge about the Company’s financial matters, satisfactory to the Representative, to the effect (1) set forth in Sections 8(b) (with respect to the respective representations, warranties, agreements and conditions of the Company) and 8(c), (2) that none of the situations set forth in clause (i) or (ii) of Section 8(d) shall have occurred and (3) that no stop order suspending the effectiveness of the Registration Statement has been issued and to the knowledge of the Company, no proceedings for that purpose have been instituted or are pending or contemplated by the Commission.

(f) On the Closing Date and the Option Date, as the case may be, the Representative shall have received a certificate, dated the respective dates of delivery thereof and addressed to the Underwriters, of its chief financial officer with respect to certain financial data contained in the Disclosure Package and the Prospectus, providing “management comfort” with respect to such information, in form and substance reasonably satisfactory to the Representative.

(g) On the Closing Date or Option Closing Date, as the case may be, DLA Piper LLP (US), counsel for the Company, shall have furnished to the Representative their favorable written opinion and negative assurance letter, dated the Closing Date or the Option Closing Date, as the case may be, in form and substance satisfactory to counsel for the Underwriters, to such effect as counsel for the Underwriters may reasonably request.

(h) On the Closing Date or Option Closing Date, as the case may be, ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ LLP, intellectual property counsel for the Company, shall have furnished to the Representative their favorable written opinion, dated the Closing Date or the Option Closing Date, as the case may be, in form and substance satisfactory to counsel for the Underwriters, to such effect as counsel for the Underwriters may reasonably request.

(i) On the Closing Date or Option Closing Date, as the case may be, the Company’s in-house counsel, shall have furnished to the Representative their favorable written opinion regarding the Company’s intellectual property, dated the Closing Date or the Option Closing Date, as the case may be, in form and substance satisfactory to counsel for the Underwriters, to such effect as counsel for the Underwriters may reasonably request.

(j) [reserved]

(k) On the date hereof, KPMG LLP shall have furnished to the Representative a letter, dated the date of delivery thereof, in form and substance satisfactory to the Representative, containing statements and information of the type customarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the Disclosure Package and the Prospectus.

(l) On the Closing Date and any Option Closing Date, as the case may be, the Representative shall have received from KPMG LLP a letter, dated the Closing Date or such Option Closing Date, as the case may be, to the effect that they reaffirm the statements made in the letter or letters furnished pursuant to Section 8(k), except that the specified date referred to shall be a date not more than two business days prior to the Closing Date or such Option Closing Date, as the case may be.

(m) On the Closing Date or Option Closing Date, as the case may be, ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇▇ & Schole LLP, counsel for the Underwriters, shall have furnished to the Representative their negative assurance letter, dated the Closing Date or the Option Closing Date, as the case may be, in form and substances reasonably satisfactory to the Representative, and such counsel shall have received such papers and information from the Company as they may reasonably request to enable them to pass upon such matters.

(n) The Shares and Warrant Shares shall have been approved for listing on the NASDAQ Global Select Market, subject to official notice of issuance.

(o) FINRA shall have raised no objection with respect to the fairness and reasonableness of the underwriting terms and conditions.

(p) The Representative shall have received “lock-up” agreements, each substantially in the form of Exhibit A hereto, from each individual listed on Schedule IV hereto and such agreements shall be in full force and effect on the Closing Date or Option Closing Date, as the case may be.

(q) On or prior to the Closing Date or Option Closing Date, as the case may be, the Company shall have furnished to the Representative such further information, certificates and documents as the Representative shall reasonably request.

(r) On or after the Applicable Time there shall not have occurred any of the following: (i) a suspension or material limitation in trading in securities generally on the NASDAQ Global Select Market; (ii) a suspension or material limitation in trading in the Company’s securities on the NASDAQ Global Select Market; (iii) a general moratorium on commercial banking activities declared by any federal or state authorities or a material disruption in commercial banking or securities settlement or clearance services in the United States; (iv) the outbreak or escalation of hostilities involving the United States or the declaration by the United States of a national emergency or war or (v) the occurrence of any other calamity or crisis or any change in financial, political or economic conditions in the United States or elsewhere, if the effect of any such event specified in clause (iv) or (v) in the judgment of the Representative makes it impracticable or inadvisable to proceed with the public offering or the delivery of the Offered Securities being delivered at such Closing Date or Option Closing Date, as the case may be, on the terms and in the manner contemplated in the Prospectus.

If any condition specified in this Section 8 shall not have been fulfilled when and as required to be fulfilled, this Agreement may be terminated, subject to the provisions of Section 12, by the Representative by notice to the Company at any time at or prior to the Closing Date or Option Closing Date, as the case may be, and such termination shall be without liability of any party to any other party, except as provided in Section 12.

9. (a) The Company agrees to indemnify and hold harmless each Underwriter and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act or Section 20(a) of the Exchange Act against any and all losses, liabilities, claims, damages and expenses whatsoever as incurred (including without limitation, reasonable attorneys’ fees and any and all reasonable expenses whatsoever incurred in investigating, preparing or defending against any litigation, commenced or threatened, or any claim whatsoever, and any and all amounts paid in settlement of any claim or litigation), to which they or any of them may become subject under the Securities Act, the Exchange Act or otherwise, insofar as such losses, liabilities, claims, damages or expenses (or actions in respect thereof) arise out of or are based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (including the Rule 430B Information and any other

information deemed to be part of the Registration Statement at the time of effectiveness and at any subsequent time pursuant to the Rules and Regulations, if applicable), or any post-effective amendment thereof, or any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, or (ii) any untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, the Disclosure Package or the Prospectus, or in any supplement thereto or amendment thereof, any Issuer Free Writing Prospectus, any Written Testing-the-Waters Communication, or any “issuer information” filed or required to be filed pursuant to Rule 433(d) under the Securities Act, or any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided, however, that the Company will not be liable in any such case to the extent that any such loss, liability, claim, damage or expense arises out of or is based upon any such untrue statement or alleged untrue statement or omission or alleged omission made in the Initial Registration Statement, as originally filed or any amendment thereof, the Registration Statement, or any post-effective amendment thereof, any Preliminary Prospectus, the Disclosure Package or the Prospectus, or in any supplement thereto or amendment thereof, any Issuer Free Writing Prospectus, or any Written Testing-the-Waters Communication in reliance upon and in conformity with written information furnished to the Company by or on behalf of any Underwriter through the Representative expressly for use therein, it being understood and agreed that the only such information furnished by any Underwriter is the information described as such in Section 9(b) below.

(b) Each Underwriter agrees to indemnify and hold harmless the Company, each of the directors of the Company, each of the officers of the Company who shall have signed the Registration Statement, and each other person, if any, who controls the Company within the meaning of Section 15 of the Securities Act or Section 20(a) of the Exchange Act, against any losses, liabilities, claims, damages and expenses whatsoever as incurred (including without limitation, reasonable attorneys’ fees and any and all reasonable expenses whatsoever incurred in investigating, preparing or defending against any litigation, commenced or threatened, or any claim whatsoever, and any and all amounts paid in settlement of any claim or litigation), to which they or any of them may become subject under the Act, the Exchange Act or otherwise, insofar as such losses, liabilities, claims, damages or expenses (or actions in respect thereof) arise out of or are based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any post-effective amendment thereof, or any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, or (ii) any untrue statement or alleged untrue statement of a material fact contained in any Preliminary Prospectus, the Disclosure Package or the Prospectus, or in any supplement thereto or amendment thereof, any Issuer Free Writing Prospectus or any Written Testing-the-Waters Communication, or any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein, in light of the circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that any such loss, liability, claim, damage or expense arises out of or is based upon any such untrue statement or alleged untrue statement or omission or alleged omission made therein in reliance upon and in conformity with written information furnished to the Company by or on behalf of such Underwriter through the Representative expressly for use therein, it being understood and agreed that the only such

information furnished by or on behalf of any Underwriter consists of the following information in the Prospectus furnished on behalf of each Underwriter: the statements with respect to the public offering of the Offered Securities by the Underwriters set forth under the subheading “Stabilization, Short Positions and Penalty Bids” under the caption “Underwriting.” Notwithstanding the provisions of this Section 9(b), no Underwriter shall be required to indemnify the Company for any amount in excess of the total underwriting discounts and commissions received by such Underwriter with respect to the offering of the Offered Securities.

(c) Promptly after receipt by an indemnified party under Section 9(a) or 9(b) of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under such Section, notify each party against whom indemnification is to be sought in writing of the commencement thereof (but the failure so to notify an indemnifying party shall not relieve it from any liability which it may have under this Section 9). In case any such action is brought against any indemnified party, and it notifies an indemnifying party of the commencement thereof, the indemnifying party will be entitled to participate therein, and jointly with any other indemnifying party similarly notified, to the extent it may elect by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof with counsel satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnified party). Notwithstanding the foregoing, the indemnified party or parties shall have the right to employ its or their own counsel in any such case, but the fees and expenses of such counsel shall be at the expense of such indemnified party or parties unless (i) the employment of such counsel shall have been authorized in writing by one of the indemnifying parties in connection with the defense of such action, (ii) the indemnifying parties shall not have employed counsel to have charge of the defense of such action within a reasonable time after notice of commencement of the action, or (iii) such indemnified party or parties shall have reasonably concluded that there may be defenses available to it or them which are different from or additional to those available to one or all of the indemnifying parties (in which case the indemnifying parties shall not have the right to direct the defense of such action on behalf of the indemnified party or parties), in any of which events such fees and expenses shall be borne by the indemnifying parties. In no event shall the indemnifying parties be liable for fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances, which counsel, in the event of indemnified parties under Section 9(a), shall be selected by the Representative. No indemnifying party shall, without the written consent of the indemnified party, effect the settlement or compromise of, or consent to the entry of any judgment with respect to, any pending or threatened action or claim in respect of which indemnification or contribution may be sought hereunder (whether or not the indemnified party is an actual or potential party to such action or claim) unless such settlement, compromise or judgment (i) includes an unconditional release of the indemnified party from all liability arising out of such action or claim and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified party.

(d) If the indemnification provided for in this Section 9 is unavailable to or insufficient to hold harmless an indemnified party under Section 9(a) or 9(b) in respect of any

losses, liabilities, claims, damages or expenses (or actions in respect thereof) referred to therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of such losses, liabilities, claims, damages or expenses (or actions in respect thereof) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other from the offering of the Offered Securities. If, however, the allocation provided by the immediately preceding sentence is not permitted by applicable law, then each indemnifying party shall contribute to such amount paid or payable by such indemnified party in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault of the Company on the one hand and the Underwriters on the other in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses (or actions in respect thereof), as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other from the offering of the Offered Securities shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses) received by the Company bear to the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover page of the Prospectus. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company on the one hand or the Underwriters on the other and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and the Underwriters agree that it would not be just and equitable if contributions pursuant to this Section 9(d) were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 9(d). The amount paid or payable by an indemnified party as a result of the losses, liabilities, claims, damages or expenses (or actions in respect thereof) referred to above in this Section 9(d) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 9(d), no Underwriter shall be required to contribute any amount in excess of the total underwriting discounts and commissions received by such Underwriter with respect to the offering of the Offered Securities.

No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation.

(e) The obligations of the parties to this Agreements contained in this Section 9 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

10. If any Underwriter or Underwriters default in its or their obligations to purchase Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Common Warrants, as applicable, hereunder on the Closing Date or any Option Closing Date and the aggregate number of Firm Shares, Prefunded Warrants and Firm Common Warrants or

Option Shares or Option Common Warrants, as applicable, that such defaulting Underwriter or Underwriters agreed but failed to purchase does not exceed 10% of the total number of Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Common Warrants, as applicable, that the Underwriters are obligated to purchase on such Closing Date or Option Closing Date, as the case may be, the Representative may make arrangements satisfactory to the Company for the purchase of such Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Common Warrants, as applicable, by other persons, including any of the Underwriters, but if no such arrangements are made by such Closing Date or Option Closing Date, as the case may be, the non-defaulting Underwriters shall be obligated, in proportion to their respective commitments hereunder, to purchase the Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Common Warrants, as applicable, that such defaulting Underwriters agreed but failed to purchase on such Closing Date or Option Closing Date, as the case may be. If any Underwriter or Underwriters so default and the aggregate number of Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Common Warrants, as applicable, with respect to which such default or defaults occur exceeds 10% of the total number of Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Warrants, as applicable, that the Underwriters are obligated to purchase on such Closing Date or Option Closing Date, as the case may be, and arrangements satisfactory to the Representative and the Company for the purchase of such Firm Shares, Prefunded Warrants and Firm Common Warrants or Option Shares or Option Common Warrants, as applicable, by other persons are not made within 36 hours after such default, this Agreement will terminate, subject to the provisions of Section 12, without liability on the part of any non-defaulting Underwriter or the Company, except as provided in Section 12. Nothing herein will relieve a defaulting Underwriter from liability for its default.

In the event of any such default which does not result in a termination of this Agreement, either the Representative or the Company shall have the right to postpone the Closing Date or the relevant Option Closing Date, as the case may be, for a period not exceeding seven days in order to effect any required changes in the Registration Statement or Prospectus or in any other documents or arrangements. As used in this Agreement, the term “Underwriter” includes any person substituted for an Underwriter under this Section 10.

11. Notwithstanding anything herein contained, this Agreement (or the obligations of the Underwriters with respect to any Option Shares or Option Common Warrants which have yet to be purchased) may be terminated, subject to the provisions of Section 12, in the absolute discretion of the Representative, by notice given to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date or the Option Closing Date, as the case may be, (a) trading generally on the NYSE American, the New York Stock Exchange, the NASDAQ Global Select Market or the NASDAQ Global Market shall have been suspended or materially limited, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices have been required, by any of said exchanges or by such system or by order of the Commission, FINRA or any other governmental or regulatory authority, (b) trading of any securities of or guaranteed by the Company or any Subsidiary shall have been suspended on any exchange or in any over-the-counter market, (c) a general moratorium on commercial banking activities in New York shall have been declared by Federal or New York State authorities or a

new restriction materially adversely affecting the distribution of the Firm Shares, Prefunded Warrants and Firm Common Warrants or the Option Shares or Option Common Warrants, as the case may be, shall have become effective, or (d) there has occurred any material adverse change in the financial markets in the United States or the international financial markets, any outbreak of hostilities or escalation thereof or other calamity or crisis or any change or development involving a prospective change in national or international political, financial or economic conditions, in each case the effect of which is such as to make it, in the judgment of the Representative, impracticable to market the Offered Securities to be delivered on the Closing Date or Option Closing Date, as the case may be, or to enforce contracts for the sale of the Offered Securities.

If this Agreement is terminated pursuant to this Section 11, such termination will be without liability of any party to any other party except as provided in Section 12 hereof.

12. The respective indemnities, agreements, representations, warranties and other statements of the Company or its officers and of the Underwriters set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation, or statement as to the results thereof, made by or on behalf of any Underwriter, the Company or any of their respective representatives, officers or directors or any controlling person, and will survive delivery of and payment for the Offered Securities. If this Agreement is terminated pursuant to Section 8, 10 or 11 or if for any reason the purchase of any of the Offered Securities by the Underwriters is not consummated, the Company shall remain responsible for the expenses to be paid or reimbursed by it pursuant to Section 7, the respective obligations of the Company and the Underwriters pursuant to Section 9 and the provisions of Sections 12, 13 and 16 shall remain in effect and, if any Offered Securities have been purchased hereunder the representations and warranties in Section 1 and all obligations under Section 5 and Section 6 shall also remain in effect. If this Agreement shall be terminated by the Underwriters, or any of them, under Section 8 or Section 11 or otherwise because of any failure or refusal on the part of the Company to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason the Company shall be unable to perform its obligations under this Agreement or any condition of the Underwriters’ obligations cannot be fulfilled, the Company agrees to reimburse the Underwriters or such Underwriters as have so terminated this Agreement with respect to themselves, for all out-of-pocket expenses (including the fees and expenses of its counsel) reasonably incurred by the Underwriter in connection with this Agreement or the offering contemplated hereunder.

13. This Agreement shall inure to the benefit of and be binding upon the Company and the Underwriters, the officers and directors of the Company referred to herein, any controlling persons referred to herein and their respective successors and assigns. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any other person, firm or corporation any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. No purchaser of Offered Securities from any Underwriter shall be deemed to be a successor or assign by reason merely of such purchase.

14. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given upon receipt thereof by the recipient if mailed or transmitted by

any standard form of telecommunication. Notices to the Underwriters shall be given to the Representative, c/o ▇▇▇▇▇-▇▇▇▇▇▇ Capital Group LLC, ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇, ▇▇▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇, email: ▇▇▇▇.▇▇▇▇▇▇▇▇@▇▇▇▇▇-▇▇▇▇▇▇.▇▇▇, attention: ▇▇▇▇ ▇▇▇▇▇▇▇▇, Director of Investment Banking. Notices to the Company shall be given to it at Sientra, Inc., ▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇, ▇▇▇▇▇ ▇▇▇▇▇▇▇, ▇▇ ▇▇▇▇▇, to the attention of General Counsel at email: ▇▇▇▇▇▇.▇▇▇▇▇▇▇@▇▇▇▇▇▇▇.▇▇▇.

15. This Agreement may be signed in counterparts, each of which shall be an original and all of which together shall constitute one and the same instrument.

16. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO SUCH STATE’S PRINCIPLES OF CONFLICTS OF LAWS.

17. The parties hereby submit to the exclusive jurisdiction of and venue in the federal courts located in the City of New York, New York in connection with any dispute related to this Agreement or any transaction contemplated hereby. Each party hereby irrevocably waives personal service of process and consents to process being served in any such action or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any other manner permitted by law.

18. The Company acknowledges and agrees that the Representative and the other Underwriters are acting solely in the capacity of an arm’s length contractual counterparty to the Company with respect to the offering of Offered Securities contemplated hereby (including in connection with determining the terms of the offering) and not as a financial advisor or a fiduciary to, or an agent of, the Company or any other person. Additionally, neither the Representative nor any other Underwriter is advising the Company or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction. The Company shall consult with its own advisors concerning such matters and shall be responsible for making its own independent investigation and appraisal of the transactions contemplated hereby, and neither the Representative nor the other Underwriters shall have any responsibility or liability to the Company with respect thereto. Any review by the Representative and the other Underwriters of the Company, the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company The Company agrees that it will not claim that the Underwriters, or any of them, has rendered advisory services of any nature or respect, or owes a fiduciary or similar duty to the Company, in connection with such transaction or the process leading thereto.

19. The Company acknowledges that the Underwriters’ research analysts and research departments are required to be independent from their respective investment banking divisions and are subject to certain regulations and internal policies, and that such Underwriters’ research analysts may hold views and make statements or investment recommendations and/or publish research reports with respect to the Company and/or the offering that differ from the

views of their respective investment banking divisions. The Company hereby waives and releases, to the fullest extent permitted by law, any claims that the Company may have against the Underwriters with respect to any conflict of interest that may arise from the fact that the views expressed by their independent research analysts and research departments may be different from or inconsistent with the views or advice communicated to the Company by such Underwriters’ investment banking divisions. The Company acknowledges that each of the Underwriters is a full service securities firm and as such from time to time, subject to applicable securities laws, may effect transactions for its own account or the account of its customers and hold long or short positions in debt or equity securities of the companies that may be the subject of the transactions contemplated by this Agreement.

20. Notwithstanding anything herein to the contrary, the Company is authorized to disclose to any persons the U.S. federal and state income tax treatment and tax structure of the potential transaction and all materials of any kind (including tax opinions and other tax analyses) provided to the Company relating to that treatment and structure, without the Underwriters imposing any limitation of any kind. However, any information relating to the tax treatment and tax structure shall remain confidential (and the foregoing sentence shall not apply) to the extent necessary to enable any person to comply with securities laws. For this purpose, “tax structure” is limited to any facts that may be relevant to that treatment.

21. This Agreement supersedes all prior agreements and understandings (whether written or oral) between the Company and the Underwriters, or any of them, with respect to the subject matter hereof. Notwithstanding anything herein to the contrary, the Engagement Agreement, dated July 5, 2022, as amended on October 3, 2022, (“Engagement Agreement”), by and between the Company and the Representative, shall continue to be effective and the terms therein shall continue to survive and be enforceable by the Representative in accordance with its terms, provided that, in the event of a conflict between the terms of the Engagement Agreement and this Agreement, the terms of this Agreement shall prevail.

22. The Company and each of the Underwriters hereby irrevocably waives, to the fullest extent permitted by applicable law, any and all right to trial by jury in any legal proceeding arising out of or relating to this Agreement or the transactions contemplated hereby.

23. In the event that any Underwriter that is a Covered Entity becomes subject to a proceeding under a U.S. Special Resolution Regime, the transfer from such Underwriter of this Agreement, and any interest and obligation in or under this Agreement, will be effective to the same extent as the transfer would be effective under the U.S. Special Resolution Regime if this Agreement, and any such interest and obligation, were governed by the laws of the United States or a state of the United States.

In the event that any Underwriter that is a Covered Entity or a BHC Act Affiliate of such Underwriter becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights under this Agreement that may be exercised against such Underwriter are permitted to be exercised to no greater extent than such Default Rights could be exercised under the U.S. Special Resolution Regime if this Agreement were governed by the laws of the United States or a state of the United States.

For purposes of this Section 23, a “BHC Act Affiliate” has the meaning assigned to the term “affiliate” in, and shall be interpreted in accordance with, 12 U.S.C. § 1841(k). “Covered Entity” means any of the following: (i) a “covered entity” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 252.82(b); (ii) a “covered bank” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 47.3(b); or (iii) a “covered FSI” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 382.2(b). “Default Right” has the meaning assigned to that term in, and shall be interpreted in accordance with, 12 C.F.R. §§ 252.81, 47.2 or 382.1, as applicable. “U.S. Special Resolution Regime” means each of (i) the Federal Deposit Insurance Act and the regulations promulgated thereunder and (ii) Title II of the ▇▇▇▇-▇▇▇▇▇ ▇▇▇▇ Street Reform and Consumer Protection Act and the regulations promulgated thereunder.

24. In accordance with the requirements of the USA Patriot Act (Title III of Pub. L.107-56 (signed into law October 26, 2001)), the Underwriters are required to obtain, verify and record information that identifies their clients, including the Company, which information may include the name and address of their clients, as well as other information that will allow the Underwriters to properly identify their clients.

25. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Counterparts may be delivered via facsimile, electronic mail (including any electronic signature covered by the U.S. federal ESIGN Act of 2000, Uniform Electronic Transactions Act, the Electronic Signatures and Records Act or other applicable law, e.g., ▇▇▇.▇▇▇▇▇▇▇▇.▇▇▇) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes.

If the foregoing is in accordance with your understanding of our agreement, please sign and return to the Company a counterpart hereof, whereupon this instrument will become a binding agreement among the Company and the Underwriters.


Very truly yours,

SIENTRA, INC.

By:		/s/ ▇▇▇▇▇▇ ▇▇▇▇▇▇▇
		Name: ▇▇▇▇▇▇ ▇▇▇▇▇▇▇
		Title: CFO


Accepted as of the date hereof:

▇▇▇▇▇-▇▇▇▇▇▇ CAPITAL GROUP LLC

By:		/s/ ▇▇▇▇▇ ▇▇▇▇
		Name: ▇▇▇▇▇ ▇▇▇▇
		Title: CEO

For itself and as Representative of the other Underwriters named in Schedule I hereto

SCHEDULE I

Underwriter

Number of
Firm Shares to
be Purchased

Number of Pre-
Funded Warrants
to be Purchased

Number of Firm
Common
Warrants to be
Purchased

▇▇▇▇▇-▇▇▇▇▇▇ Capital Group LLC

12,567,610

22,214,990

34,782,600

Total

12,567,610

22,214,990

34,782,600

SCHEDULE II

Free Writing Prospectuses

SCHEDULE III

Pricing Information

Public Offering Price per share: $0.3799 per share

Public Offering Price per Prefunded Warrant: $0.3699 per Prefunded Warrant

Public Offering Price per Common Warrant: $0.0001 per Common Warrant

Number of Firm Shares: 12,567,610

Number of Prefunded Warrants: 22,214,990

Number of Firm Common Warrants: 34,782,600

Number of Option Shares: 5,217,390

Number of Option Common Warrants: 5,217,390

Exercise Price of the Firm Common Warrants: $0.46

Gross Spread per share: $0.01900 per share

Gross Spread per Prefunded Warrant: $0.01850 per Prefunded Warrant

SCHEDULE IV

Lock-up Individuals

•	Officers (as such term is defined under Section 16 of the Exchange Act) of the Company

▇▇▇ ▇▇▇▇▇▇▇

▇▇▇▇ ▇▇▇▇▇▇▇

▇▇▇▇▇▇ ▇▇▇▇▇▇▇

•	Directors of the Company:

▇▇▇▇ ▇▇▇▇▇▇▇▇

▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇

▇▇▇▇▇ ▇’▇▇▇▇▇

▇▇▇▇▇▇▇▇ ▇ ▇▇▇▇▇▇▇▇

▇▇▇▇▇ ▇▇▇▇▇▇▇▇

▇▇▇▇ ▇. ▇▇▇▇▇▇

▇▇. ▇▇▇▇▇ ▇▇▇▇▇▇▇▇

EXHIBIT A

FORM OF LOCK-UP AGREEMENT

SIENTRA, INC.

▇▇▇ ▇. ▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇

▇▇▇▇▇ ▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇

▇▇▇▇▇-▇▇▇▇▇▇ CAPITAL GROUP LLC

As representative of the Underwriters

▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇

▇▇▇▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇

Ladies and Gentlemen:

The undersigned refers to the proposed Underwriting Agreement (the “Underwriting Agreement”) among Sientra, Inc., a Delaware corporation (the “Company”), and the underwriters named therein (the “Underwriters”), for whom ▇▇▇▇▇-▇▇▇▇▇▇ Capital Group LLC (the “Representative”) is acting as representative. As an inducement to the Representative to execute the Underwriting Agreement on behalf of the Underwriters in connection with the proposed public offering of shares of the Company’s common stock, par value $0.01 per share (“Common Stock”), and prefunded Common Stock purchase warrants (the “Prefunded Warrants”) pursuant to a Registration Statement on Form S-3, as amended or supplemented, the undersigned hereby agrees that from the date hereof and until 90 days after the public offering date set forth on the final prospectus supplement used to sell the Common Stock (the “Public Offering Date”) pursuant to the Underwriting Agreement (such 90 day period being referred to herein as the “Lock-Up Period”), the undersigned will not (and will cause any spouse or immediate family member of the spouse or the undersigned living in the undersigned’s household, any partnership, corporation or other entity within the undersigned’s control, and any trustee of any trust that holds Common Stock or other securities of the Company for the benefit of the undersigned or such spouse or family member not to) offer, sell, contract to sell (including any short sale), pledge, hypothecate, establish an open “put equivalent position” within the meaning of Rule 16a-1(h) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), grant any option, right or warrant for the sale of, purchase any option or contract to sell, sell any option or contract to purchase, or otherwise encumber, dispose of or transfer, or grant any rights with respect to, directly or indirectly, any shares of Common Stock or securities convertible into or exchangeable or exercisable for any shares of Common Stock (including, without limitation, shares of Common Stock that may be deemed to be beneficially owned by the undersigned in accordance with the rules and regulations of the Securities and Exchange Commission), enter into a transaction which would have the same effect, or enter into any swap, hedge or other arrangement that transfers, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such aforementioned transaction is to be settled by delivery of the Common Stock or such other securities, in cash or otherwise, or publicly disclose the intention to make any such offer, sale, pledge or disposition, or to enter into any such transaction, swap, hedge or other arrangement, without, in each case, the prior written consent of the Representative, which consent may be withheld in the Representative’s sole

discretion. For purposes of this Agreement, “immediate family” shall mean any relationship by blood, current or former marriage or adoption, not more remote than first cousin.

Notwithstanding the foregoing, the undersigned may transfer the undersigned’s shares of Common Stock or securities convertible into or exchangeable or exercisable for any shares of Common Stock (i) as a bona fide gift or gifts, (ii) to an immediate family member or any trust, corporation, partnership, limited liability company or other business entity for the direct or indirect benefit of the undersigned or the immediate family of the undersigned, (iii) if the undersigned is a corporation, partnership, limited liability company, trust or other business entity and (1) transfers to another corporation, partnership, limited liability company, trust or other business entity that is a direct or indirect affiliate (as defined in Rule 405 promulgated under the Securities Act of 1933, as amended) of the undersigned or (2) distributes shares of Common Stock or any security convertible into or exercisable for Common Stock to limited partners, limited liability company members or stockholders of the undersigned, or to any investment fund or other entity that controls or manages the undersigned (including, for the avoidance of doubt, a fund managed by the same manager or managing member or general partner or management company or by an entity controlling, controlled by, or under common control with such manager or managing member or general partner or management company as the undersigned or who shares a common investment advisor with the undersigned), (iv) if the undersigned is a trust, transfers to the beneficiary of such trust, (v) via transfer by testate succession or intestate succession, (vi) to a nominee or custodian or a person or entity to whom a disposition or transfer would be permissible under clauses (i) through (v) above, (vii) if the undersigned is an employee of the Company and transfers to the Company upon death, disability or termination of employment of such employee, (viii) [reserved], (ix) acquired pursuant to the Underwriting Agreement, (x) pursuant to an order of a court or regulatory agency, or (xi) with the prior written consent of the Representative; provided, in the case of clauses (i)-(viii) that (a) such transfer shall not involve a disposition for value, (b) each resulting transferee of the Company’s securities executes and delivers to the Representative an agreement satisfactory to the Representative certifying that such transferee is bound by the terms of this Agreement and has been in compliance with the terms hereof since the date first above written as if it had been an original party hereto, (c) to the extent any interest in the Company’s securities is retained by the undersigned (or such spouse or family member), such securities shall remain subject to the restrictions contained in this Agreement and (d) in the case of clauses (i)-(viii), no filing by any party under Section 16(a) of the Exchange Act shall be required or shall be made voluntarily in connection with such transfer.

In addition, the foregoing restrictions shall not apply to (i) the exercise of stock options granted pursuant to the Company’s equity incentive plans, the conversion or exercise of warrants into Common Stock or into any other security convertible into or exercisable for Common Stock that are outstanding as of the date of the prospectus and described therein; provided that such restrictions shall apply to any of the undersigned’s shares of Common Stock or any security convertible into or exercisable for Common Stock issued upon such conversion or exercise except as provided herein; (ii) forfeitures to satisfy tax withholding obligations in connection with the conversion or exercise of such options, warrants or restricted stock units, (iii) transfers pursuant to a “change of control” of the Company (including, without limitation, the entering into any lock-up, voting or similar agreement pursuant to which the undersigned may agree to

transfer, sell, tender or otherwise dispose of common stock or other such securities in connection with such transaction, or vote any common stock or other such securities in favor of any such transaction); provided that in the event that such tender offer, merger, consolidation or other such transaction is not completed, such securities held by the undersigned shall remain subject to the provisions of this Agreement (for purposes of this letter agreement, “change of control” shall mean the consummation of any bona fide third party tender offer, merger, consolidation or other similar transaction the result of which is that any “person” (as defined in Section 13(d)(3) of the Exchange Act), or group of persons, other than the Company, becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 of the Exchange Act) of a majority of total voting power of the voting stock of the Company), (iv) sales of shares of Common Stock to cover tax payments resulting from the vesting of any restricted stock units, provided that (1) any required filing under Section 16 of the Exchange Act made during the Lock-Up Period shall clearly indicate (A) that the filing relates to the circumstances described above and (B) no Common Stock or any other security convertible into or exercisable for Common Stock were sold by the reporting person other than such transfers as described above and (2) the undersigned does not otherwise voluntarily effect any other public filing or report regarding such transfers during the Lock-Up Period, or (v) the establishment of any contract, instruction or plan (a “Plan”) that satisfies all of the requirements of Rule 10b5-1(c)(1)(i)(B) under the Exchange Act; provided that no sales of the undersigned’s shares of Common Stock or any security convertible into or exercisable for Common Stock shall be made pursuant to such a Plan prior to the expiration of the Lock-Up Period, and such a Plan may only be established if no public announcement of the establishment or existence thereof and no filing with the Securities and Exchange Commission or other regulatory authority in respect thereof or transactions thereunder or contemplated thereby, by the undersigned, the Company or any other person, shall be required, and no such announcement or filing is made voluntarily, by the undersigned, the Company or any other person, prior to the expiration of the Lock-Up Period.

In addition, the undersigned agrees that, during the period commencing on the date hereof and ending 90 days after the Public Offering Date, without the prior written consent of the Representative (which consent may be withheld in its sole discretion): (a) the undersigned will not request, make any demand for or exercise any right with respect to, the registration of any Common Stock or any security convertible into or exercisable or exchangeable for Common Stock and (b) the undersigned waives any and all notice requirements and rights with respect to the registration of any such security pursuant to any agreement, understanding or otherwise to which the undersigned is a party.

In furtherance of the foregoing, the Company and its transfer agent and registrar are hereby authorized to (a) decline to make any transfer of shares of Common Stock if such transfer would constitute a violation or breach of this Agreement and (b) place legends and stop transfer instructions on any such shares of Common Stock owned or beneficially owned by the undersigned.

The undersigned acknowledges and agrees that none of the Underwriters has made any recommendation or provided any investment or other advice to the undersigned with respect to this Agreement or the subject matter hereof, and the undersigned has consulted its own legal,

accounting, financial, regulatory, tax and other advisors with respect to this Agreement and the subject matter hereof to the extent the undersigned has deemed appropriate.

This Agreement may be delivered via facsimile, electronic mail (including pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., ▇▇▇.▇▇▇▇▇▇▇▇.▇▇▇ or ▇▇▇.▇▇▇▇▇▇▇▇.▇▇▇) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes.

This Agreement is irrevocable and shall be binding on the undersigned and the successors, heirs, personal representatives and assigns of the undersigned. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to choice of law rules. This Agreement shall lapse and become null and void if the Public Offering Date shall not have occurred on or before October 31, 2022.


Very truly yours,



Printed Name:

Date:

12,567,610 Shares of Common Stock, 22,214,990 Prefunded Warrants (to purchase 22,214,990 shares of Common Stock) and 34,782,600 Common Warrants (to purchase 34,782,600 shares of Common Stock) SIENTRA, INC. UNDERWRITING AGREEMENT

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