Exhibit 1.1

REGENXBIO INC.

Common Stock

(par value $0.0001 per share)

ATM EQUITY OFFERING^SM SALES AGREEMENT

September 1, 2023

BofA Securities, Inc.

One Bryant Park

New York, New York 10036

Ladies and Gentlemen:

REGENXBIO Inc., a Delaware corporation (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell from time to time to or through BofA Securities, Inc., as sales agent and/or principal (the “Agent”), shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), having an aggregate gross sales price not to exceed $150,000,000, on the terms set forth in this ATM Equity Offering^SM Sales Agreement. The Company agrees that whenever it determines to sell Shares directly to the Agent as principal it will enter into a separate written Terms Agreement (each, a “Terms Agreement”), in substantially the form of Annex I hereto, relating to such sale in accordance with Section 2(k) hereof. References herein to “this Agreement” or to matters contained “herein” or “hereunder”, or words of similar import, mean this ATM Equity Offering^SM Sales Agreement and any applicable Terms Agreement.

The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) an “automatic shelf registration statement,” as defined under Rule 405 (“Rule 405”) under the Securities Act of 1933, as amended (the “1933 Act”), on Form S-3 (File No. 333-269086), covering the public offering and sale of certain securities of the Company, including the Shares, under the 1933 Act and the rules and regulations promulgated thereunder (the “1933 Act Regulations”), which automatic shelf registration statement became effective under Rule 462(e) of the 1933 Act Regulations (“Rule 462(e)”) upon filing with the Commission on December 30, 2022. The “Registration Statement,” as of any time, means such registration statement as amended by any post-effective amendments thereto at such time, including the exhibits and any schedules thereto at such time, the documents incorporated or deemed to be incorporated by reference therein at such time pursuant to Item 12 of Form S-3 under the 1933 Act and the documents otherwise deemed to be a part thereof as of such time pursuant to Rule 430B of the 1933 Act Regulations (“Rule 430B”); provided, however, that the “Registration Statement” without reference to a time means such registration statement as amended by any post-effective amendments thereto as of the time of the first contract of sale for the Shares, which time shall be considered the “new effective date” of the Registration Statement with respect to the Shares within the meaning of paragraph (f)(2) of Rule 430B (“Rule 430B(f)(2)”), including the exhibits and schedules thereto at such time, the documents incorporated or deemed to be incorporated by reference therein at such time pursuant to Item 12 of Form S-3 under the 1933 Act and the documents otherwise deemed to be a part thereof as of such time pursuant to Rule 430B. The base prospectus filed as part of such automatic shelf registration statement, as amended in the form in which it has been filed most recently with the Commission in accordance with Section 3(b) or 3(c) hereof, including the documents incorporated or deemed to be incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act, is referred to herein as the “Base Prospectus.” Promptly after execution and delivery of this Agreement, the Company will prepare and file a prospectus supplement relating to the Shares in accordance with the provisions of Rule 424(b) of the 1933 Act Regulations (“Rule 424(b)”). Such final prospectus supplement, as amended by the prospectus supplement filed most recently with the Commission in accordance with Section 3(b), 3(c) or 3(n) hereof, as the case may be, including the documents incorporated or deemed to be incorporated by reference therein pursuant to Item 12 of Form S-3 under the 1933 Act, is referred to herein as the “Prospectus Supplement.” The Base Prospectus, as amended by the Prospectus Supplement and any applicable pricing supplement thereto, in the form the Base Prospectus, the Prospectus Supplement and any such pricing supplement are first furnished to the Agent for use in connection with the offering and sale of Shares, are collectively referred to herein as the “Prospectus.” For purposes of this Agreement, all references to the Registration Statement, any preliminary prospectus or the Prospectus or any amendment or supplement thereto 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) (“EDGAR”).

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As used in this Agreement:

“Applicable Time” means, with respect to any offer and sale of Shares, the time immediately prior to the first contract of sale for such Shares.

“General Disclosure Package” means each Issuer General Use Free Writing Prospectus, if any, issued prior to the Applicable Time, the most recent Prospectus filed with the Commission in accordance with Section 3(b), 3(c) or 3(n) hereof that is distributed to investors prior to the Applicable Time and the number of Shares and the initial offering price per Share, all considered together.

“Issuer Free Writing Prospectus” means any “issuer free writing prospectus,” as defined in Rule 433 of the 1933 Act Regulations (“Rule 433”), including, without limitation, any “free writing prospectus” (as defined in Rule 405) relating to the Shares that is (i) required to be filed with the Commission by the Company, (ii) a “road show for an offering that is a written communication” within the meaning of Rule 433(d)(8)(i), whether or not required to be filed with the Commission, or (iii) exempt from filing with the Commission pursuant to Rule 433(d)(5)(i) because it contains a description of the Shares or of the offering thereof that does not reflect the final terms, in each case in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s records pursuant to Rule 433(g).

“Issuer General Use Free Writing Prospectus” means any Issuer Free Writing Prospectus approved by the Agent pursuant to Section 3(l) hereof that is furnished to the Agent for general distribution to investors, as evidenced by communications between the Company and the Agent.

“Issuer Limited Use Free Writing Prospectus” means any Issuer Free Writing Prospectus that is not an Issuer General Use Free Writing Prospectus.

All references in this Agreement to financial statements and schedules and other information which is “contained,” “included,” “made,” “stated” or “referred to” (or other references of like import) in the Registration Statement, any preliminary prospectus or the Prospectus shall be deemed to include all such financial statements and schedules and other information incorporated or deemed to be incorporated by reference in the Registration Statement, any preliminary prospectus or the Prospectus, as the case may be, prior to the Applicable Time relating to the particular Shares; and all references in this Agreement to amendments or supplements to the Registration Statement, any preliminary prospectus or the Prospectus shall be deemed to include the filing of any document under the Securities Exchange Act of 1934, as amended (the “1934 Act”), and the rules and regulations promulgated thereunder (the “1934 Act Regulations”), incorporated or deemed to be incorporated by reference in the Registration Statement, such preliminary prospectus or the Prospectus, as the case may be, at or after the Applicable Time relating to the particular Shares.

Section 1. Representations and Warranties. The Company represents and warrants to the Agent at the date of this Agreement, each Registration Statement Amendment Date (as defined in Section 3(o) hereof), each Company Periodic Report Date (as defined in Section 3(n) hereof), each Updating Form 8-K Date (as defined in Section 3(o) hereof), each Applicable Time and each Settlement Date (as defined in Section 2(h) hereof) (collectively, a “Representation Date”), and agrees with the Agent, as follows:

(i) Compliance of the Registration Statement, the Prospectus and Incorporated Documents. The Company meets the requirements for use of Form S-3 under the 1933 Act. The Registration Statement is an automatic shelf registration statement under Rule 405 and the Shares have been and remain eligible for registration by the Company on such automatic shelf registration statement. Each of the Registration Statement and any post-effective amendment thereto has become effective under the 1933 Act. No stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto

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has been issued under the 1933 Act, no notice of objection of the Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) of the 1933 Act Regulations (“Rule 401(g)(2)”) has been received by the Company, no order preventing or suspending the use of any preliminary prospectus or the Prospectus or any amendment or supplement thereto has been issued and no proceedings for any of those purposes have been instituted or are pending or, to the Company’s knowledge, threatened by the Commission. The Company has complied with each request (if any) from the Commission for additional information.

Each of the Registration Statement and any post-effective amendment thereto, at the time of its effectiveness and as of each deemed effective date with respect to the Agent pursuant to Rule 430B(f)(2), complied in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations. Each of any preliminary prospectus and the Prospectus and any amendment or supplement thereto, at the time it was filed with the Commission, complied in all material respects with the requirements of the 1933 Act and the 1933 Act Regulations and is identical to the electronically transmitted copy thereof filed with the Commission pursuant to EDGAR, except to the extent permitted by Regulation S-T.

The documents incorporated or deemed to be incorporated by reference in the Registration Statement, any preliminary prospectus and the Prospectus, when they became effective or at the time they were or hereafter are filed with the Commission, complied and will comply in all material respects with the requirements of the 1934 Act and the 1934 Act Regulations.

(ii) Accurate Disclosure. Neither the Registration Statement nor any amendment thereto, at its effective time or at any Settlement Date, contained, contains or will contain an untrue statement of a material fact or omitted, omits or will omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. At each Applicable Time, neither (A) the General Disclosure Package nor (B) any individual Issuer Limited Use Free Writing Prospectus, when considered together with the General Disclosure Package, included, includes or will include an untrue statement of a material fact or omitted, omits or will 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. Neither the Prospectus nor any amendment or supplement thereto (including any prospectus wrapper), as of its issue date, at the time of any filing with the Commission pursuant to Rule 424(b) or at any Settlement Date, included, includes or will include an untrue statement of a material fact or omitted, omits or will 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. The documents incorporated or deemed to be incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus, at the time the Registration Statement became effective or when such documents incorporated by reference were or hereafter are filed with the Commission, as the case may be, when read together with the other information in the Registration Statement, the General Disclosure Package or the Prospectus, as the case may be, did not, do not and will not include 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.

(iii) Issuer Free Writing Prospectuses. No Issuer Free Writing Prospectus conflicts or will conflict with the information contained in the Registration Statement, any preliminary prospectus or the Prospectus or any amendment or supplement thereto, including any document incorporated by reference therein, that has not been superseded or modified. Any offer that is a written communication relating to the Shares made prior to the initial filing of the Registration Statement by the Company or any person acting on its behalf (within the meaning, for this paragraph only, of Rule 163(c) of the 1933 Act Regulations) has been filed with the Commission in accordance with the exemption provided by Rule 163 of the 1933 Act Regulations (“Rule 163”) and otherwise complied with the requirements of Rule 163, including, without limitation, the legending requirement, to qualify such offer for the exemption from Section 5(c) of the 1933 Act provided by Rule 163.

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(iv) Well-Known Seasoned Issuer. (A) At the original effectiveness of the Registration Statement and (B) at the date of this ATM Equity OfferingSM Sales Agreement, the Company was a “well-known seasoned issuer” as defined in Rule 405.

(v) Company Not Ineligible Issuer. (A) At the time of filing the Registration Statement and any post-effective amendment thereto, (B) at the earliest time thereafter that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2) of the 1933 Act Regulations) of the Shares, (C) at the date of this ATM Equity Offering^SM Sales Agreement and any Terms Agreement and (D) at each Applicable Time, the Company was not and is not an “ineligible issuer,” as defined in Rule 405, without taking account of any determination by the Commission pursuant to Rule 405 that it is not necessary that the Company be considered an ineligible issuer.

(vi) Independent Accountants. PricewaterhouseCoopers LLP, which has certified certain financial statements and supporting schedules of the Company included in the Registration Statement, the General Disclosure Package and the Prospectus, is an independent registered public accounting firm with respect to the Company within the meaning of the 1933 Act, the 1933 Act Regulations, 1934 Act and the 1934 Act Regulations and the Public Company Accounting Oversight Board (United States).

(vii) Financial Statements; Non-GAAP Financial Measures. The financial statements of the Company included or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus, together with the related schedules and notes thereto, present fairly in all material respects the consolidated financial position of the Company and its subsidiaries as of the dates shown and its results of operations and cash flows for the periods shown, and, except as otherwise disclosed in the Registration Statement, the General Disclosure Package or the Prospectus, such financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) applied on a consistent basis throughout the periods covered thereby, except for any normal year-end adjustments in the Company’s quarterly financial statements. Except as included in the Registration Statement, the General Disclosure Package and the Prospectus, no historical or pro forma financial statements or supporting schedules are required to be included in the Registration Statement, any preliminary prospectus or the Prospectus under the 1933 Act or the 1933 Act Regulations. All disclosures contained in the Registration Statement, the General Disclosure Package or the Prospectus, if any, regarding “non-GAAP financial measures” (as such term is defined by the rules and regulations of the Commission) comply with Regulation G under the 1934 Act and Item 10 of Regulation S-K under the 1933 Act, to the extent applicable. The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the General 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.

(viii) No Material Adverse Change. Except as stated in the Registration Statement, the General Disclosure Package and the Prospectus, since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Prospectus, (A) there has been no material adverse change, or any development involving a prospective change that would reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, business, operations or prospects of the Company and its subsidiaries, taken as a whole (a “Material Adverse Change”), (B) there have been no transactions entered into by the Company or any of its subsidiaries, other than those in the ordinary course of business, which are material with respect to the Company and its subsidiaries considered as one enterprise, and (C) subsequent to the respective dates as of which financial information is given in each of the Registration Statement, the General Disclosure Package and the Prospectus, (i) the Company and its subsidiaries have not incurred any material liability or obligation, direct or contingent, nor entered into any material transaction; (ii) the Company and its subsidiaries have not purchased any of the Company’s outstanding capital stock (other than from their employees in connection with the termination of their service pursuant to plans or agreements described in all material respects in each of the Registration Statement, the General Disclosure Package and the Prospectus, respectively), nor declared, paid or otherwise made any dividend or distribution of any kind on the Company’s capital stock other than ordinary and customary dividends; and (iii) there has not been any material change in the capital stock, short-term debt or long-term debt of the Company or any of its subsidiaries, except in each case as described in each of the Registration Statement, the General Disclosure Package and the Prospectus, respectively.

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(ix) Good Standing of the Company. The Company has been duly incorporated, is validly existing as a corporation in good standing under the laws of the State of Delaware, has the corporate power and authority to own its property and to conduct its business as described in the Registration Statement, the General Disclosure Package and the Prospectus and to enter into and perform its obligations under, and to consummate the transactions contemplated in, this Agreement. The Company is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or to be in good standing would not reasonably be expected to have a material adverse effect on the Company and its subsidiaries, taken as a whole (collectively, a “Material Adverse Effect”).

(x) Good Standing of Subsidiaries. Each subsidiary of the Company has been duly incorporated, is validly existing in good standing (which concept shall include the functional equivalent of “good standing” in non-U.S. jurisdictions, to the extent applicable) under the laws of the jurisdiction of its incorporation, has the applicable power and authority to own its property and to conduct its business and is duly qualified to transact business and is in good standing in each jurisdiction in which the conduct of its business or its ownership or leasing of property requires such qualification, except to the extent that the failure to be so qualified or to be in good standing would not result in a Material Adverse Effect; all of the issued shares of capital stock of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly by the Company, free and clear of all liens, encumbrances, equities or claims.

(xi) Capitalization; Listing of Common Stock. The authorized, issued and outstanding shares of capital stock of the Company are as set forth in the Registration Statement and the Prospectus (except for subsequent issuances, if any, pursuant to this Agreement, pursuant to reservations, agreements or employee benefit plans, including any employee stock purchase plan, referred to in the Registration Statement, the General Disclosure Package and the Prospectus or pursuant to the exercise of convertible securities or options referred to in the Registration Statement, the General Disclosure Package and the Prospectus). The outstanding shares of capital stock of the Company have been duly authorized and validly issued and are fully paid and non-assessable. None of the outstanding shares of capital stock of the Company were issued in violation of the preemptive or other similar rights of any stockholder of the Company or any other person or entity. The Company’s Common Stock has been registered pursuant to Section 12(b) of the 1934 Act, the Company will use its commercially reasonable efforts to cause the Shares to be approved for listing, subject to official notice of issuance, on the Nasdaq Global Select Market (“Nasdaq”) and to maintain such listing, 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 1934 Act or the listing of the Common Stock (including the Shares) on Nasdaq, nor has the Company received any notification that the Commission or Nasdaq is contemplating terminating such registration or listing.

(xii) Authorization of this Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

(xiii) Description of Shares. The Common Stock conforms as to legal matters to the description thereof contained in the Registration Statement, the General Disclosure Package and the Prospectus.

(xiv) Authorization of Shares. The Shares have been duly authorized for issuance and sale by the Company pursuant to this Agreement and, when issued, delivered and paid for in accordance with the terms of this Agreement, will be validly issued, fully paid and non-assessable. The issuance of such Shares is not and will not be subject to any preemptive or similar rights that have not been waived.

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(xv) Registration Rights. Except as described in the Registration Statement, the General Disclosure Package and the Prospectus or with respect to shares of the Company’s Common Stock registered for resale pursuant to the Company’s Registration Statement on Form S-3 (File No. 333-273727) filed with the Commission on August 4, 2023, or as have been waived, there are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act or comparable foreign program with respect to any securities of the Company or to require the Company to include such securities with the Shares registered pursuant to the Registration Statement.

(xvi) Absence of Violations, Defaults and Conflicts. The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement will not contravene any provision of (i) applicable law, (ii) the certificate of incorporation or bylaws of the Company, (iii) any agreement or other instrument binding upon the Company or any of its subsidiaries that is material to the Company and its subsidiaries, taken as a whole, or (iv) any judgment, order or decree of any governmental body, agency or court having jurisdiction over the Company or any subsidiary, except that in the case of clauses (i) and (iii) as would not, individually or in the aggregate, reasonably be expected to have a material adverse effect on the Company and its subsidiaries, taken as a whole, or on the power and ability of the Company to perform its obligations under this Agreement; and no consent, approval, authorization or order of, or qualification with, any governmental body or agency is required to be obtained by the Company for the performance by the Company of its obligations under this Agreement, except such as have already been obtained or made or as may be required by the securities or Blue Sky laws of the various states or the rules and regulations of the Financial Industry Regulatory Authority, Inc. (“FINRA”) in connection with the offer and sale of the Shares.

(xvii) Absence of Labor Dispute. No labor dispute with the employees of the Company or its subsidiaries exists, except as described in the Registration Statement, the General Disclosure Package or the Prospectus, or, to the knowledge of the Company, is imminent that would reasonably be expected to result in a Material Adverse Effect; and the Company and its subsidiaries have not received any written notice of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that would reasonably be expected to result in a Material Adverse Effect.

(xviii) Absence of Proceedings. There are no legal or governmental proceedings pending or threatened in writing to which the Company or any of its subsidiaries is, or, to the Company’s knowledge, may be, a party or to which any of the properties of the Company or any of its subsidiaries is, or, to the Company’s knowledge, may, individually or in the aggregate, be subject (i) other than proceedings accurately described in all material respects in the Registration Statement, the General Disclosure Package and the Prospectus, and proceedings that if determined adversely to the Company would not reasonably be expected to have a Material Adverse Effect on the Company and its subsidiaries, taken as a whole, or on the power or ability of the Company to perform its obligations under this Agreement or to consummate the transactions contemplated by the Registration Statement, the General Disclosure Package and the Prospectus or (ii) that are required to be described in the Registration Statement, the General Disclosure Package or the Prospectus and are not so described; and there are no statutes, regulations, contracts or other documents that are required to be described in the Registration Statement, the General Disclosure Package or the Prospectus or to be filed as exhibits to the Registration Statement that are not described or filed as required.

(xix) Accuracy of Exhibits. There are no contracts or documents which are required to be described in the Registration Statement, any preliminary prospectus or the Prospectus or to be filed as exhibits to the Registration Statement which have not been so described and filed as required.

(xx) Absence of Further Requirements. No consent, approval, authorization or order of, or qualification with, any Governmental Entity is required to be obtained by the Company for the performance by the Company of its obligations under this Agreement, except such as have already been obtained or made or as may be required by the securities or Blue Sky laws of the various states or the rules and regulations of FINRA in connection with the offer and sale of the Shares.

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(xxi) Possession of Licenses and Permits. The Company and each of its subsidiaries possess all licenses, certificates, permits and other authorizations issued by, and have made all declarations and filings with, the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the ownership or lease of their properties or the conduct of their business as described in the Registration Statement, the General Disclosure Package and the Prospectus, and except as described in the each of the Registration Statement, the General Disclosure Package and the Prospectus, the Company and its subsidiaries have not received notice of any revocation or modification of any such license, certificate, permit or authorization or have any reason to believe that any such license, certificate, permit or authorization will not be renewed in the ordinary course. Except as described in each of the Registration Statement, the General Disclosure Package and the Prospectus, the Company and its subsidiaries (i) are, and at all times have been, in compliance in all material respects with all statutes, rules and regulations applicable to the ownership, testing, development, manufacture, packaging, processing, use, distribution, storage, import, export or disposal of any product manufactured or distributed by the Company (“Applicable Laws”), and (ii) have not received any FDA Form 483, written notice of adverse finding, warning letter, untitled letter or other correspondence or written notice from any court or arbitrator or governmental or regulatory authority alleging or asserting non- compliance with (x) any Applicable Laws or (y) any licenses, exemptions, certificates, approvals, clearances, authorizations, permits and supplements or amendments thereto required by any such Applicable Laws. The Company and its subsidiaries have not received written notice of any claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any court or arbitrator or governmental or regulatory authority or third party alleging that any operation or activity is in material violation of any Applicable Laws, and no such notice of any claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action is threatened. The Company and its subsidiaries are not a party to any corporate integrity agreements, monitoring agreements, consent decrees, settlement orders, or similar agreements with or imposed by any governmental or regulatory authority. Additionally, to the Company’s knowledge, none of its employees, officers or directors has been excluded, suspended or debarred from participation in any U.S. federal health care program, clinical or pre-clinical research or comparable foreign program or is subject to a governmental inquiry, investigation, proceeding, or other similar action that could reasonably be expected to result in debarment, suspension, or exclusion.

(xxii) Title to Property. The Company and each of its subsidiaries have good and marketable title in fee simple to all real property and good and marketable title to all tangible personal property owned by it which is material to the business of the Company and its subsidiaries in each case free and clear of all liens, encumbrances and defects of title except such as (A) are described in the Registration Statement, the General Disclosure Package and the Prospectus or (B) do not materially affect the value of such property and do not materially interfere with the use made and proposed to be made of such property by the Company or its subsidiaries; and any real property and buildings held under lease by the Company or any of its subsidiaries are held by them under valid, subsisting and, to the Company’s knowledge, enforceable leases with such exceptions as are not material and do not materially interfere with the use made and proposed to be made of such property and buildings by the Company or its subsidiaries, in each case except as described in the Registration Statement, the General Disclosure Package or the Prospectus.

(xxiii) Intellectual Property. The Company and each of its subsidiaries own or possess, or can acquire on commercially reasonable terms, rights in or to all patents, patent rights, licenses, inventions, copyrights, know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks, trade names, domain names, and other similar intellectual property or proprietary rights (including all registrations and applications for registration of, and all goodwill associated with, the foregoing) (collectively, “Intellectual Property”), in each case necessary for the conduct of the business of the Company and its subsidiaries, taken as a whole, in all material respects as currently conducted and as proposed to be conducted in the Registration Statement, General Disclosure Package and/or Prospectus, provided that, nothing in this sentence shall be

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deemed or otherwise interpreted to be a representation regarding infringement, misappropriation or other violation of Intellectual Property rights of others. To the knowledge of the Company, the Company and its subsidiaries have not infringed, misappropriated or otherwise violated any Intellectual Property of any third party in any material respect. The Company and its subsidiaries have not received any written notice of infringement, misappropriation or other violation of, or conflict with, any Intellectual Property of any third party, or any written notice challenging the validity, enforceability, ownership or scope of any Intellectual Property of the Company or any of its subsidiaries, in each case, which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would result in a Material Adverse Effect. To the knowledge of the Company, all material Intellectual Property of the Company and its subsidiaries is valid and enforceable.

(xxiv) Environmental Laws. The Company and its subsidiaries i) are in compliance with any and all applicable foreign, federal, state and local laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (“Environmental Laws”), ii) have received all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses and iii) are in compliance with all terms and conditions of any such permit, license or approval, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or other approvals or failure to comply with the terms and conditions of such permits, licenses or approvals would not, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect. There are no costs or liabilities associated with Environmental Laws (including, without limitation, any capital or operating expenditures required for clean-up, closure of properties or compliance with Environmental Laws or any permit, license or approval, any related constraints on operating activities and any potential liabilities to third parties pursuant to Environmental Laws) which would, singly or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(xxv) No Termination or Non-Renewal. Except as described in the Registration Statement, the General Disclosure Package and the Prospectus, the Company and its subsidiaries have not sent or received any communication regarding termination of, or intent not to renew, any of the contracts or agreements referred to or described in the Registration Statement, the General Disclosure Package, the Prospectus or any free writing prospectus, or referred to or described in, or filed as an exhibit to, the Registration Statement, and no such termination or non-renewal has been threatened by the Company or any of its subsidiaries or, to the Company’s knowledge, any other party to any such contract or agreement, which threat of termination or non-renewal has not been rescinded as of the date hereof.

(xxvi) Compliance with Regulatory Authorities. (i) Except as described in the Registration Statement, the General Disclosure Package and the Prospectus, the pre-clinical trials and other tests conducted by or (x) on behalf of or sponsored by the Company or any of its subsidiaries, or (y) in which the Company or any of its subsidiaries has participated, that are described in the Prospectus, or the results of which are referred to in the Prospectus, as applicable, were, and if still pending, are being conducted in all material respects in accordance with standard medical and scientific research standards and procedures for products or product candidates comparable to those being developed by the Company and its subsidiaries and all applicable statutes and all applicable rules, regulations and guidance documents of the U.S. Food and Drug Administration (“FDA”) and comparable regulatory agencies outside of the United States to which they are subject, including the European Commission and the European Medicines Agency (collectively, the “Regulatory Authorities”) and current Good Clinical Practices and Good Laboratory Practices; (ii) the descriptions in the Prospectus of the results of such studies and tests are materially accurate and complete descriptions and fairly present the material data derived therefrom; (iii) the Company has no knowledge of any other trials or tests conducted by or (x) on behalf of or sponsored by the Company or any of its subsidiaries, or (y) in which the Company or any of its subsidiaries has participated that are not described in the Prospectus, the results of which are materially inconsistent with or raise questions concerning the validity of the results described or referred to in the Prospectus; (iv) the Company and its subsidiaries have operated at all times and are currently in compliance in all material respects with all applicable statutes, rules and regulations of the Regulatory Authorities; and (v) except as described in

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the Prospectus, the Company and its subsidiaries have not received any written notices, correspondence or other communications from the Regulatory Authorities or any other governmental agency requiring or threatening the termination, modification or suspension of any clinical or pre-clinical trials or other clinical or pre-clinical tests that are described in the Prospectus or the results of which are referred to in the Prospectus, other than ordinary course communications with respect to modifications in connection with the design and implementation of such trials and tests, and there are no reasonable grounds for the same.

The Company and its subsidiaries have not failed to file with the Regulatory Authorities any required filing, declaration, listing, registration, report or submission with respect to the Company’s product candidates or pre-clinical trials or other tests that are described or referred to in the Prospectus; all such filings, declarations, listings, registrations, reports or submissions were in compliance with applicable laws when filed; and no deficiencies regarding compliance with applicable law have been asserted by any applicable regulatory authority with respect to any such filings, declarations, listings, registrations, reports or submissions.

(xxvii) Accounting Controls and Disclosure Controls. The Company and each of its subsidiaries maintain effective internal control over financial reporting (as defined under Rule 13-a15 and Rule 15d-15 of the 1934 Act Regulations) and a system of internal accounting controls sufficient to provide reasonable assurances that: (A) transactions are executed in accordance with management’s general or specific authorizations; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain asset accountability; (C) access to assets is permitted only in accordance with management’s general or specific authorization; (D) 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 (E) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the General Disclosure Package and the Prospectus is accurate. Except as described in each of the Registration Statement, the General Disclosure Package and the Prospectus, since the end of the Company’s most recent audited fiscal year, there has been (i) no material weakness in the Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially adversely affected, or is reasonably likely to materially adversely affect, the Company’s internal control over financial reporting.

(xxviii) Payment of Taxes. The Company and each of its subsidiaries have filed all federal, state, local and foreign tax returns required to be filed through the date of this Agreement or have requested extensions thereof (except where the failure to file would not, individually or in the aggregate, result in a Material Adverse Effect) and have paid all taxes required to be paid thereon (except as currently being contested in good faith and for which reserves required by GAAP have been created in the financial statements of the Company), and no tax deficiency has been determined adversely to the Company or its subsidiaries which has had (nor do the Company or its subsidiaries have any notice or knowledge of any tax deficiency which could reasonably be expected to be determined adversely to the Company and its subsidiaries and which would reasonably be expected to have) a Material Adverse Effect.

(xxix) ERISA Compliance. Each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), for which the Company or any member of its controlled group of corporations within the meaning of Section 414 of the Internal Revenue Code of 1986, as amended (the “Code”), would have any liability 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 Code, except for such noncompliance, as would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect.

(xxx) Insurance. The Company and each of its subsidiaries are insured by insurers of recognized financial responsibility against such losses and risks and in such amounts as, in the reasonable judgment of the Company, are prudent and customary in the business in which it is engaged; the Company and its subsidiaries have not been refused any insurance coverage sought or applied for; and the Company

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and its subsidiaries have no reason to believe that they will not be able to renew their respective 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 reasonably be expected to have a Material Adverse Effect, except as described in the Registration Statement, the General Disclosure Package and the Prospectus.

(xxxi) Investment Company Act. The Company is not, and upon the issuance and sale of the Shares as contemplated herein and the application of the net proceeds therefrom as described in the Registration Statement, the General Disclosure Package and the Prospectus will not be, required to register as an “investment company” as such term is defined in the Investment Company Act of 1940, as amended (the “1940 Act”).

(xxxii) Absence of Manipulation. Neither the Company nor any affiliate of the Company has taken, nor will the Company or any such affiliate take, directly or indirectly, any action which is designed, or would be expected, to cause or result in, or which constitutes, the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of any Shares or to result in a violation of Regulation M under the 1934 Act.

(xxxiii) No Unlawful Payments. (i) None of the Company or its subsidiaries, or any director or officer, nor, to the Company’s knowledge, any employee, affiliate, agent, representative, or other person acting on behalf of the Company or any of its subsidiaries or affiliates, has taken (or will take) any action in furtherance of an offer, payment, promise to pay, or authorization or approval of the payment or giving of money, property, gifts or anything else of value, directly or indirectly, to any “government official” (including any officer or employee of a government or government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of any of the foregoing, or any political party or party official or candidate for political office) to improperly influence official action or secure an improper advantage; (ii) the Company and its subsidiaries and, to the Company’s knowledge, its affiliates have conducted their businesses in compliance with applicable anti-corruption laws and have instituted and maintained (and will maintain) policies and procedures designed to promote and achieve compliance with such laws and with the representation and warranty contained herein; and (iii) neither the Company nor its subsidiaries will use, directly or indirectly, the proceeds of the offering in furtherance of an offer, payment, promise to pay, or authorization of the payment or giving of money, or anything else of value, to any person in violation of any applicable anti-corruption laws.

(xxxiv) Money Laundering Laws. The operations of the Company and its subsidiaries are and have been conducted at all times in compliance in all material respects with all applicable financial recordkeeping and reporting requirements, including those of the Bank Secrecy Act, as amended by Title III of the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001 (“USA PATRIOT Act”), and the applicable anti-money laundering statutes of jurisdictions where the Company and its subsidiaries conduct business, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Anti- Money Laundering Laws”), and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Anti-Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

(xxxv) OFAC. (A) None of the Company, any of its subsidiaries or any director or officer, or, to the Company’s knowledge, any employee thereof or any agent, affiliate or representative of the Company or any of its subsidiaries, is an individual or entity (“Person”) that is, or is owned or controlled by a Person that is: (i) 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, His Majesty’s Treasury, or other relevant sanctions authority (collectively, “Sanctions”), nor is the Company or any of its subsidiaries (ii) located, organized or resident in a country or territory that is the subject or target of Sanctions (including, without limitation, the non-government controlled areas of the Zaporizhzhia and

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Kherson Regions of Ukraine, the so-called Donetsk People’s Republic, the so-called Luhansk People’s Republic or any other Covered Region of Ukraine identified pursuant to Executive Order 14065 and the Crimea region of Ukraine, Cuba, Iran, North Korea and Syria (each, a “Sanctioned Country”)), and (B) 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 Person: (i) to fund or facilitate any activities or business of or with any Person or in any country or territory that, at the time of such funding or facilitation, is the subject or target of Sanctions; or (iii) in any other manner that will result in a violation of Sanctions by any Person (including any Person participating in the offering, whether as underwriter, advisor, investor or otherwise). For the past five years, the Company and its subsidiaries have not knowingly engaged in, are not now knowingly engaged in, and will not engage in, any dealings or transactions with any Person, or in any country or territory, that at the time of the dealing or transaction is or was the subject or the target of Sanctions or with any Sanctioned Country.

(xxxvi) Cybersecurity; Data Protection. The Company and its subsidiaries have complied, and are presently in compliance, in all material respects, with all of their internal and external privacy policies and contractual obligations and all applicable laws, statutes, judgments, orders, rules and regulations of any court or arbitrator or other governmental or regulatory authority and any legal obligations, in each case, regarding the collection, use, transfer, import, export, storage, protection, disposal, disclosure and other processing by the Company and its subsidiaries of data related to identified or identifiable individuals (“Data Security Obligations”, and such data, “Personal Data”). Neither the Company nor any of its subsidiaries has received any notification of or complaint regarding, and neither the Company nor any of its subsidiaries is aware of any other facts that, individually or in the aggregate, would reasonably indicate non-compliance in any material respect with any Data Security Obligation. There is no pending, or to the knowledge of the Company, threatened, claim, action, suit or proceeding by or before any court or governmental agency, authority or body alleging non-compliance with any Data Security Obligation, other than proceedings that if determined adversely to the Company would not reasonably be expected to result in a Material Adverse Effect. The Company and its subsidiaries have taken commercially reasonable steps to protect the Personal Data against loss and against unauthorized access, use, modification, disclosure or other misuse, except in each case to the extent that the failure to do so would not reasonably be expected to result in a Material Adverse Effect. To the knowledge of the Company, except as would not individually or in the aggregate have a Material Adverse Effect, there has been no unauthorized access to any of the Personal Data.

Any certificate signed by any officer or other authorized signatory of the Company and delivered to the Agent or to counsel for the Agent shall be deemed a representation and warranty by the Company to the Agent as to the matters covered thereby.

Section 2. Sale and Delivery of Shares.

(a) Subject to the terms and conditions set forth herein, the Company agrees to issue and sell Shares through the Agent, acting as sales agent, or directly to the Agent, acting as principal, from time to time. Sales of the Shares, if any, through the Agent acting as sales agent or directly to the Agent acting as principal will be made by means of ordinary brokers’ transactions on Nasdaq or otherwise at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices.

(b) The Shares are to be sold to the Agent on an agented basis on any day (other than a day on which Nasdaq is scheduled to close prior to its regular weekday closing time) (each, a “Trading Day”) on which (i) the Company has instructed the Agent to make such sales and (ii) the Company has satisfied its covenants and conditions specified in Sections 4 and 5 hereof. On any Trading Day, the Company may sell Shares through the Agent and, if it determines to do so, shall instruct the Agent by telephone (confirmed promptly by telecopy or email, which confirmation will be promptly acknowledged by the Agent) as to the maximum number of Shares to be sold on such Trading Day and the minimum price per Share at which such Shares may be sold. Subject to the terms and conditions specified herein (including, without limitation, the accuracy of the representations and warranties of the Company and the performance by the Company of its covenants and other obligations, contained herein and the

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satisfaction of the additional conditions specified in Section 5 hereof), the Agent shall use commercially reasonable efforts, consistent with its normal trading and sales practices and applicable law and regulations, to sell all of the Shares so designated by the Company as sales agent in accordance with such instruction. The Company and the Agent each acknowledge and agree that (A) there can be no assurance that the Agent will be successful in selling any Shares and (B) the Agent will not incur any liability or obligation to the Company if it fails to sell Shares for any reason other than a failure to use commercially reasonable efforts, consistent with its normal trading and sales practices and applicable law and regulations, to sell such Shares as required by this Agreement.

(c) The Company or the Agent may, upon notice to the other party hereto by telephone (confirmed promptly by telecopy or email, which confirmation will be promptly acknowledged by the receiving party), suspend the offering of Shares with respect to which the Agent is acting as sales agent for any reason and at any time; provided, however, that such suspension shall not affect or impair the parties’ respective obligations with respect to the Shares sold, or with respect to Shares that the Company has agreed to sell, hereunder prior to the giving of such notice.

(d) The gross sales price of any Shares sold pursuant to this Agreement by the Agent acting as sales agent of the Company shall be equal to, in the discretion of the Agent but subject to the specific instructions of the Company, the market price prevailing at the time of sale for the Shares sold by the Agent on Nasdaq or otherwise, at prices related to prevailing market prices or at negotiated prices. The compensation payable to the Agent for sales of Shares with respect to which the Agent acts as sales agent shall be up to 3.0% of the gross sales price for such Shares unless another amount is agreed upon by the Company and the Agent. The remaining proceeds, after further deduction for any transaction fees, transfer taxes or similar taxes or fees imposed by any Governmental Entity or self-regulatory organization in respect of such sales, shall constitute the net proceeds to the Company for such sales (the “Net Proceeds”). The Agent shall notify the Company as promptly as practicable if any deduction referenced in the preceding sentence will be made.

(e) If acting as sales agent hereunder, the Agent shall provide written confirmation to the Company following the close of trading on Nasdaq on each Trading Day on which Shares are sold under this Agreement setting forth the number of Shares sold on such day, the aggregate gross sales proceeds of the Shares, the aggregate Net Proceeds to the Company and the aggregate compensation payable by the Company to the Agent with respect to such sales.

(f) Under no circumstances shall the aggregate gross sales price of Shares offered or sold pursuant to this Agreement, or which are the subject of instructions to the Agent as sales agent pursuant to Section 2(b) hereof, exceed the aggregate gross sales price of Shares (i) referred to in the preamble paragraph of this Agreement, as reduced by prior sales of Shares under this Agreement, (ii) available for sale under the Registration Statement or (iii) duly authorized from time to time to be issued and sold under this Agreement by the Company or approved for listing on Nasdaq, and, in each case referred to in clause (ii) and (iii), notified to the Agent in writing. In addition, under no circumstances shall any Shares with respect to which the Agent acts as sales agent, be offered or sold, or be the subject of instructions to the Agent pursuant to Section 2(b) hereof, at a price lower than the minimum price therefor duly authorized from time to time by the Company and notified to the Agent in writing. The Agent shall have no responsibility for maintaining records with respect to Shares available for sale under the Registration Statement or for determining the aggregate gross sales price, number or minimum price of Shares duly authorized by the Company.

(g) If, prior to any sell order, the exemptive provisions set forth in Rule 101(c)(1) of Regulation M under the 1934 Act are not satisfied with respect to the Company or the Shares, the Company shall promptly notify the Agent and future offers and sales of Shares through the Agent on an agented basis under this Agreement shall be suspended until that or other exemptive provisions have been satisfied in the judgment of each party.

(h) Settlement for sales of Shares will occur (i) prior to May 28, 2024, on the second Trading Day following the date on which such sales are made and (ii) beginning May 28, 2024, on the first Trading Day following the date on which such sales are made, in each case unless another date shall be agreed to in writing by the Company and the Agent (each such day, a “Settlement Date”). On each Settlement Date for the sale of Shares

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through the Agent as sales agent, such Shares shall be delivered by the Company to the Agent in book-entry form to the Agent’s account at The Depository Trust Company against payment by the Agent of the Net Proceeds from the sale of such Shares in same day funds delivered to an account designated by the Company. If the Company shall default on its obligation to deliver Shares through the Agent as sales agent on any Settlement Date, the Company shall (i) indemnify and hold the Agent harmless against any loss, claim or damage arising from or as a result of such default by the Company and (ii) pay the Agent any commission to which it would otherwise be entitled absent such default.

(i) Notwithstanding any other provision of this Agreement, the Company shall not offer or sell, or instruct the Agent to offer or sell, any Shares through the Agent as sales agent (and, by notice to the Agent given by telephone (confirmed promptly by telecopy or email), shall cancel any instructions for any such offer or sale of any Shares prior to the commencement of the periods referenced below), and the Agent shall not be obligated to make any such offer or sale of Shares, (i) during any period in which the Company is, or could be deemed to be, in possession of material non-public information or (ii) except as provided in Section 2(j) hereof, at any time during the period commencing on the 10^th business day prior to the time the Company issues a press release containing, or shall otherwise publicly announce, its earnings, revenues or other operating results for a fiscal period or periods (each, an “Earnings Announcement”) through and including the time that is 24 hours after the time that the Company files a Quarterly Report on Form 10-Q or an Annual Report on Form 10-K (a “Filing Time”) that includes consolidated financial statements as of and for the same fiscal period or periods, as the case may be, covered by such Earnings Announcement.

(j) Notwithstanding clause (ii) of Section 2(i) hereof, if the Company wishes to offer or sell Shares to the Agent as sales agent at any time during the period from and including an Earnings Announcement through and including the corresponding Filing Time, the Company shall first (i) prepare and deliver to the Agent (with a copy to counsel for the Agent) a Current Report on Form 8-K that includes substantially the same financial and related information that was included in such Earnings Announcement (other than any earnings projections and similar forward-looking data and officers’ quotations) (each, an “Earnings 8-K”), in form and substance reasonably satisfactory to the Agent, and, prior to its filing, obtain the written consent of the Agent to such filing (which consent shall not be unreasonably withheld), (ii) provide the Agent with the officers’ certificate, opinions and letters of counsel and accountants’ letter specified in Section 3(o), (p) and (q), respectively, hereof, (iii) afford the Agent the opportunity to conduct a due diligence review in accordance with Section 3(t) hereof prior to filing such Earnings 8-K and (iv) file such Earnings 8-K with the Commission. For purposes of clarity, the parties hereto agree that (A) the delivery of any officers’ certificate, opinion or letter of counsel or accountants’ letter pursuant to this Section 2(j) shall not relieve the Company from any of its obligations under this Agreement with respect to any Quarterly Report on Form 10-Q or Annual Report on Form 10-K, as the case may be, including, without limitation, the obligation to deliver officers’ certificates, opinions and letters of counsel and accountants’ letters as provided in Section 3(o), (p) and (q), respectively, hereof, unless such obligations have been waived under Section 3(r), and (B) this Section 2(j) shall in no way affect or limit the operation of clause (i) of Section 2(i) hereof, which shall have independent application.

(k) The Agent shall not have any obligation to purchase Shares as principal, whether from the Company or otherwise, unless the Company and the Agent agree as set forth below. Shares purchased from the Company by the Agent as principal shall be made in accordance with terms agreed upon between the Agent and the Company as evidenced by a Terms Agreement. The Agent’s commitment to purchase Shares from the Company as principal shall be deemed to have been made on the basis of the accuracy of the representations and warranties of the Company, and performance by the Company of its covenants and other obligations, herein contained and shall be subject to the terms and conditions herein set forth. At the time of each Terms Agreement, the Agent shall specify the requirements, if any, for the officers’ certificate, opinions and letters of counsel and accountants’ letter pursuant to Section 3(o), (p) and (q), respectively, hereof. In the event of a conflict between the terms of this ATM Equity Offering^SM Sales Agreement and a Terms Agreement, the terms of such Terms Agreement shall control.

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Section 3. Covenants. The Company agrees with the Agent:

(a) Compliance with Securities Regulations and Commission Requests. The Company, subject to Section 3(b) and 3(c) hereof, will comply with the requirements of Rule 430B, and will promptly notify the Agent, and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement or any new registration statement relating to the Shares being offered pursuant to this Agreement shall become effective or any amendment or supplement to the Prospectus shall have been filed (other than an amendment or supplement providing solely for the determination of the terms of an offering of securities unless related to an offering of Shares pursuant to this Agreement), (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, including any document incorporated by reference therein, or for additional information, (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto or any notice of objection to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) or of the issuance of any order preventing or suspending the use of any preliminary prospectus or the Prospectus or any amendment or supplement thereto, or of the suspension of the qualification of any Shares for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes or of any examination pursuant to Section 8(d) or 8(e) of the 1933 Act concerning the Registration Statement and (v) if the Company becomes the subject of a proceeding under Section 8A of the 1933 Act in connection with any offering of Shares. In connection with a Terms Agreement, the Company will prepare and file with the Commission, subject to Section 3(c) hereof, a pricing supplement with respect to the offer and sale of Shares covered by such Terms Agreement. The Company will effect all filings required under Rule 424(b), in the manner and within the time period required by Rule 424(b) (without reliance on Rule 424(b)(8)). The Company will make reasonable efforts to prevent the issuance of any stop, prevention or suspension order and, if any such order is issued, to obtain the lifting thereof at the earliest possible moment. In the event of any issuance of a notice of objection, by the Commission, the Company shall exercise reasonable efforts to permit offers and sales of Shares by or through the Agent, including, without limitation, amending the Registration Statement or filing a new shelf registration statement relating thereto. The Company shall pay the required Commission filing fees relating to the Shares prior to the time the initial Prospectus Supplement is filed with the Commission or the time any subsequent Prospectus Supplement that increases gross offering price or number of Shares that may offered and sold under this Agreement from that referenced in the immediately preceding Prospectus Supplement filed with the Commission.

(b) Continued Compliance with Securities Laws. The Company will comply with the 1933 Act, the 1933 Act Regulations, the 1934 Act and the 1934 Act Regulations so as to permit the completion of sales of Shares as contemplated in this Agreement and in the Registration Statement, the General Disclosure Package and the Prospectus. If any event shall occur or condition shall exist as a result of which it is necessary, in the opinion of counsel for the Agent or counsel to the Company, to (i) amend the Registration Statement in order that the Registration Statement will not include 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, (ii) amend or supplement the General Disclosure Package or the Prospectus in order that the General Disclosure Package or the Prospectus, as the case may be, will not include any untrue statement 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 is delivered to a purchaser or (iii) amend the Registration Statement or amend or supplement the General Disclosure Package or the Prospectus, as the case may be, including, without limitation, the filing of any document incorporated by reference therein, in order to comply with the requirements of the 1933 Act, the 1933 Act Regulations, the 1934 Act or the 1934 Act Regulations, the Company will promptly (A) give the Agent written notice of such event or condition, (B) prepare any amendment or supplement as may be necessary to correct such statement or omission or to comply with such requirements and, a reasonable amount of time prior to any proposed filing or use, furnish the Agent with copies of any such amendment or supplement and (C) file with the Commission any such amendment or supplement and use its commercially reasonable efforts to have any amendment to the Registration Statement declared effective by the Commission as soon as possible if the Company is no longer eligible to file an automatic shelf registration statement; provided, however, that the Company shall not file or use any such amendment or supplement to which the Agent or counsel for the Agent shall reasonably object.

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(c) Filing or Use of Amendments and Supplements. During the period beginning on the delivery by the Company of a notice for the placement of Shares under this Agreement and ending on the applicable Settlement Date, the Company will give the Agent written notice of its intention to file or use any amendment to the Registration Statement or any amendment or supplement to the General Disclosure Package or the Prospectus (other than an amendment or supplement thereto relating solely to the offering of securities unless related to an offering of Shares pursuant to this Agreement), whether pursuant to the 1933 Act, the 1934 Act or otherwise. The Company will give the Agent written notice of its intention to file or use of (i) any post-effective amendment to the Registration Statement relating to the offer and sale of the Shares, (ii) any new Prospectus Supplement that includes information in addition to the information referred to in Section 3(n) hereof, or (iii) a pricing supplement disclosing the offer and sale of Shares covered by a Terms Agreement. Where the Company is obligated by this Section 3(c) to provide such written notice to the Agent, the Company will furnish the Agent with copies of any such document 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 Agent or counsel for the Agent shall reasonably object.

(d) Delivery of Registration Statements. The Company has furnished or will deliver to the Agent and counsel for the Agent, without charge, signed copies of the Registration Statement as originally filed and each post-effective amendment thereto (including exhibits filed therewith or incorporated by reference therein and documents incorporated or deemed to be incorporated by reference therein) and signed copies of all consents and certificates of experts; provided, however that the Company shall not be required to furnish any document to the Agent or their counsel to the extent such document is available on EDGAR.

(e) Delivery of Prospectuses. The Company will furnish to the Agent, without charge, upon execution of this Agreement and thereafter during the period in which a prospectus is (or, but for the exception afforded by Rule 172 of the 1933 Act Regulations (“Rule 172”), would be) required by the 1933 Act to be delivered in connection with any offer or sale of Shares, such number of copies of the Prospectus (as amended or supplemented) as the Agent may reasonably request. The Company will also furnish, upon request of the Agent copies of the Prospectus (as amended or supplemented) to each exchange or market on which sales of Shares were made as may be required by the rules and regulations of such exchange or market. Notwithstanding the foregoing, the Company shall not be required to furnish any document to the Agent or their counsel to the extent such document is available on EDGAR.

(f) Reporting Requirements. The Company, during the period in which a prospectus is (or, but for the exception afforded by Rule 172, would be) required by the 1933 Act to be delivered in connection with any offer or sale of Shares, will file all documents required to be filed with the Commission pursuant to the 1934 Act within the time periods prescribed by, and meeting the requirements of, the 1934 Act and the 1934 Act Regulations. Additionally, the Company shall report the use of the net proceeds from the sale of any Shares as may be required under the 1933 Act and the 1933 Act Regulations.

(g) Blue Sky Qualifications. The Company will use its commercially reasonable efforts, in cooperation with the Agent to qualify the Shares for offering and sale under the applicable securities laws of such states and non-U.S. jurisdictions as the Agent may, from time to time, designate and to maintain such qualifications in effect so long as required to complete the sale of the Shares contemplated by this Agreement; provided, however, that in connection therewith the Company shall not be required to qualify as a foreign corporation or to file a general consent to service of process in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject.

(h) Earnings Statement. The Company will timely file such reports pursuant to the 1934 Act as are necessary in order to make generally available to its stockholders as soon as practicable an earnings statement for the purposes of, and to provide to the Agent the benefits contemplated by, the last paragraph of Section 11(a) of the 1933 Act and the 1933 Act Regulations, which requirement may be satisfied by publicly filing the required information on EDGAR.

(i) Use of Proceeds. The Company will use the net proceeds received by it from the sale of the Shares pursuant to this Agreement in the manner specified in the Registration Statement, the General Disclosure Package and the Prospectus under “Use of Proceeds.”

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(j) Listing. The Company will use its commercially reasonable efforts to effect and maintain the listing of the Shares on, and satisfy the requirements of, Nasdaq.

(k) Notice of Certain Actions. During the period beginning on the delivery by the Company of a notice for the placement of Shares under this Agreement and ending on the applicable Settlement Date, the Company will not, without the prior written consent of the Agent, unless it gives the Agent at least five business days’ prior written notice, (i) directly or indirectly offer, pledge, 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 any shares of Common Stock or any securities convertible into or exercisable or exchangeable for shares of Common Stock or file any registration statement under the 1933 Act with respect to any of the foregoing or (ii) enter into any swap or any other agreement or transaction that transfers to another, in whole or in part, directly or indirectly, any of the economic consequences of ownership of the Common Stock, whether any such swap, agreement or 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 foregoing sentence shall not apply to (A) the Shares to be sold hereunder, (B) any issuance by the Company of shares of Common Stock or securities convertible into or exercisable for shares of Common Stock upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof and referred to in the Registration Statement, the General Disclosure Package and the Prospectus, (C) any shares of Common Stock or other securities convertible into or exercisable for shares of Common Stock issued pursuant to the Company’s existing equity incentive plans, including any employee stock purchase plan, described in the Registration Statement, the General Disclosure Package and the Prospectus, and (D) any shares of Common Stock or other securities convertible into or exercisable for shares of Common Stock issued pursuant to any non-employee director stock plan or dividend reinvestment plan referred to in the Registration Statement, the General Disclosure Package and the Prospectus. Upon receipt of any written notice contemplated above, the Agent may suspend its activity under this Agreement for such period of time as deemed appropriate by the Agent.

(l) Issuer Free Writing Prospectuses. The Company agrees that, unless it obtains the prior written consent of the Agent, it will not make any offer relating to the Shares that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus,” or a portion thereof, required to be filed by the Company with the Commission or retained by the Company under Rule 433. The Company represents that it has treated or agrees that it will treat each such free writing prospectus consented to by the Agent as an “issuer free writing prospectus,” as defined in Rule 433, and that it will comply with the applicable requirements of Rule 433 with respect thereto, including timely filing with the Commission where required, legending and record keeping. If at any time following the issuance of an Issuer Free Writing Prospectus any event shall occur or condition shall exist as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement, any preliminary prospectus or the Prospectus or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at that subsequent time, not misleading, the Company will promptly notify the Agent and will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission.

(m) No Stabilization or Manipulation. The Company agrees that neither it nor any affiliate of the Company will take, directly or indirectly, any action which is designed, or would be expected, to cause or result in, or which constitutes, the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of any Shares or to result in a violation of Regulation M under the 1934 Act.

(n) Update of Activity under this Agreement. The Company shall disclose (i) in each Annual Report on Form 10-K or Quarterly Report on Form 10-Q filed by the Company in respect of any fiscal quarterly period (which, in the case of an Annual Report on Form 10-K, would mean the last quarterly period of the fiscal year) in which sales of Shares were made by or through the Agent under this Agreement (each date on which any such document or amendment thereto is filed, a “Company Periodic Report Date”), or (ii) to the extent required by applicable law and/or interpretations of the Commission, in Prospectus Supplements for each such fiscal quarterly period, the number of Shares sold by or through the Agent under this Agreement during such fiscal quarterly period and the net proceeds received by the Company with respect to such sales.

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(o) Delivery of Future Officers’ Certificates. Upon commencement of the offering of Shares under this Agreement, (A) each time Shares are delivered prior to the delivery of the first instruction to the Agent as principal on a Settlement Date with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement and (B) promptly after each (i) date on which the Registration Statement shall be amended or a new registration statement relating to the offer and sale of Shares pursuant to this Agreement shall become effective or the Prospectus shall be amended or supplemented (other than (1) by an amendment or supplement providing solely for the determination of the terms of securities, including the Shares, (2) in connection with the filing of a Prospectus Supplement that contains solely the information referred to in Section 3(n) hereof, or (3) in connection with the filing of any Current Report on Form 8-K other than such filing that results in an Updating Form 8-K Date (as defined below) (each such date, a “Registration Statement Amendment Date”), (ii) Company Periodic Report Date and (iii) filing of a Current Report on Form 8-K containing amended financial information (other than information “furnished” pursuant to Items 2.02 or 7.01 of Form 8-K or to provide disclosure pursuant to Item 8.01 of Form 8-K relating to the reclassification of certain properties as discontinued operations in accordance with Statement of Financial Accounting Standards No. 144) (each such date, an “Updating Form 8-K Date”)), and (C) promptly after each reasonable request by the Agent (each date of any such request by the Agent, a “Request”) the Company will furnish or cause to be furnished to the Agent an officers’ certificate, dated such date, in form and substance reasonably satisfactory to the Agent, to the effect that the statements contained in the officers’ certificate referred to in Section 5(f) hereof that was last furnished to the Agent are true and correct as of the date of such certificate as though made at and as of the date of such certificate (except that such statements shall be deemed to relate to the Registration Statement, the General Disclosure Package and the Prospectus as amended and supplemented at the date of such certificate) or, in lieu of such certificate, a certificate of the same tenor as the certificate referred to in Section 5(f) hereof that, but modified as necessary to relate to the Registration Statement, the General Disclosure Package and the Prospectus as amended and supplemented at the date of such certificate. As used in this Section 3(o), to the extent there shall be a sale of Shares on or following any Registration Statement Amendment Date, Company Periodic Report Date, Request or Updating Form 8-K Date, “promptly” shall be deemed to be at or prior to the Applicable Time for such sale.

(p) Delivery of Future Opinions and Letters of Counsel. Upon commencement of the offering of Shares under this Agreement, (A) each time Shares are delivered prior to the delivery of the first instruction to the Agent as principal on a Settlement Date with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement and (B) promptly after each Registration Statement Amendment Date, Company Periodic Report Date, Request or Updating Form 8-K Date, the Company will furnish or cause to be furnished to the Agent the written opinions and letters of each of counsel to the Company and counsel to the Agent, dated such date, in form and substance reasonably satisfactory to the Agent of the same tenor as the respective opinions and letters referred to in Section 5(b) and 5(c), as applicable, hereof but modified as necessary to relate to the Registration Statement, the General Disclosure Package and the Prospectus as amended and supplemented to the date of such opinion and letter or, in lieu of any such opinion and letter, counsel last furnishing such opinion and letter to the Agent shall furnish the Agent with a letter substantially to the effect that the Agent may rely on such counsel’s last opinion and letter to the same extent as though each were dated the date of such letter authorizing reliance (except that statements in such last opinion and letter shall be deemed to relate to the Registration Statement, the General Disclosure Package and the Prospectus as amended and supplemented to the date of such letter authorizing reliance). As used in this Section 3(p), to the extent there shall be a sale of Shares on or following any Registration Statement Amendment Date, Company Periodic Report Date, Request or Updating Form 8-K Date, “promptly” shall be deemed to be at or prior to the Applicable Time for such sale.

(q) Delivery of Future Accountants’ Letters. Upon commencement of the offering of Shares under this Agreement, (A) each time Shares are delivered prior to the Agent as principal on a Settlement Date prior to the delivery of the first instruction to the Agent with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement and (B) promptly after each Registration Statement Amendment Date, Company Periodic Report Date, Request or Updating Form 8-K Date, the Company will cause its independent accountants to furnish to the Agent a letter, dated such date, in form and substance reasonably satisfactory to the Agent of the same tenor as the letter referred to in Section 5(d) hereof but modified as necessary to relate to the Registration Statement, the General Disclosure Package and the Prospectus as amended and supplemented to the date of such letter. As used in this Section 3(q), to the extent there shall be a sale of Shares on or following any Registration Statement Amendment Date, Company Periodic Report Date, Request or Updating Form 8-K Date, “promptly” shall be deemed to be at or prior to the Applicable Time for such sale.

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(r) Waiver of Future Delivery Obligations. The Company may notify the Agent by telephone (confirmed promptly by electronic mail), or by such other method as the Company and the Agent shall mutually agree in writing, at any time until 5:00 p.m., New York City time, on the second business day preceding any Representation Date (other than the Company Periodic Report Date relating to the date of filing of the Company’s Annual Report on Form 10-K) that it does not intend to sell Shares under this Agreement for the period commencing on such Representation Date and continuing until the next succeeding Representation Date. If the Company shall have provided such notice, the requirements to provide the certificate pursuant to Section 3(o) hereunder, legal opinions and letters, as the case may be, pursuant to Section 3(p) hereunder, a letter or letters from accountants pursuant to Section 3(q) hereunder shall be waived in respect of such Representation Date. Notwithstanding the foregoing, if the Company delivers an instruction for the sale of Shares to the Agent at a time that is (i) following a Representation Date in respect of which deliveries to the Agent of the documents required by any of Section 3(o), Section 3(p), and Section 3(q) hereunder were waived, and (ii) prior to the next Representation Date, the Agent shall not be obligated to sell any Shares pursuant to such instruction until all documents required by each such applicable section of this Agreement shall have been provided to the Agent and the Company shall have provided the Agent with a customary due diligence update.

(s) Trading in the Common Stock. The Company acknowledges that the Agent may trade in the Company’s Common Stock, to the extent permitted under the 1933 Act, 1933 Act Regulations, 1934 Act and 1934 Act Regulations, for its own account and for the account of its clients while this Agreement is in effect.

(t) Non-Consummation Offer. If, to the knowledge of the Company, any filing required by Rule 424 in connection with an offering of Shares shall not have been made or the representations and warranties of the Company contained in this Agreement shall not be true and correct on the applicable Settlement Date, the Company will offer to any person who has agreed to purchase Shares from or through the Agent the right to refuse to purchase and pay for such Shares.

(u) Due Diligence Review. The Company will cooperate with any due diligence review reasonably requested by the Agent or counsel for the Agent, fully and in a timely manner, in connection with offers and sales of Shares from time to time, including, without limitation, and upon reasonable notice, providing information and making available documents and appropriate corporate officers, during regular business hours and at the Company’s principal offices.

(v) Renewal Deadline. If, immediately prior to the third anniversary of the initial effective date of the Registration Statement (the “Renewal Deadline”), this Agreement is still in effect or any Shares purchased by the Agent as principal remain unsold, the Company will, prior to the Renewal Deadline, file, if it is eligible to do so, a new automatic shelf registration statement relating to the Shares, in a form and substance satisfactory to the Agent. If, at the time the Company intends to file such a new automatic shelf registration statement, it is not eligible to do so, the Company will, prior to the Renewal Deadline, (i) file a new shelf registration statement on the proper form relating to the Shares, in a form and substance reasonably satisfactory to the Agent, (ii) use commercially reasonable efforts to cause such new shelf registration statement to be declared effective within 60 days after the Renewal Deadline and (iii) promptly notify the Agent of such effectiveness. The Company will take all other action necessary or appropriate to permit the offering and sale of the Shares to continue as contemplated in the expired Registration Statement. References herein to the “Registration Statement” shall include such new automatic shelf registration statement or such new shelf registration statement, as the case may be.

(w) Ceasing Eligibility For Use of Automatic Shelf Registration Statement Form. If, at any time, during the term of this Agreement or otherwise when Shares purchased by the Agent as principal remain unsold, the Company receives a notice from the Commission pursuant to Rule 401(g)(2) or otherwise ceases to be eligible to use the automatic shelf registration statement form, the Company will (i) promptly notify the Agent, (ii) promptly file a new shelf registration statement or post-effective amendment on the proper form relating to such Shares, in form and substance satisfactory to the Agent, (iii) use commercially reasonable efforts to cause such new shelf

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registration statement or post-effective amendment to be declared effective as soon as practicable and (iv) promptly notify the Agent of such effectiveness. The Company will take all other action necessary or appropriate to permit the offering and sale of the Shares to continue as contemplated in the Registration Statement that was the subject of the Rule 401(g)(2) notice or for which the Company has otherwise become ineligible. References herein to the “Registration Statement” shall include such new shelf registration statement or post-effective amendment, as the case may be.

Section 4. Payment of Expenses.

(a) Expenses. The Company will pay or cause to be paid all expenses incident to the performance of its obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and exhibits) as originally filed and each amendment thereto, (ii) the preparation, printing and delivery to the Agent of copies of any preliminary prospectus, any Issuer Free Writing Prospectus and the Prospectus and any amendments or supplements thereto and any costs associated with electronic delivery of any of the foregoing by the Agent to investors, (iii) the preparation, issuance and delivery of the certificates for the Shares, if applicable, including any stock or other transfer taxes and any stamp or other duties payable upon the sale, issuance or delivery of the Shares to the Agent, (iv) the fees and disbursements of the Company’s counsel, accountants and other advisors, (v) the qualification of the Shares under securities laws in accordance with the provisions of Section 3(g) hereof, including filing fees, (vi) the fees and expenses of any transfer agent or registrar for the Shares, (vii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the Shares, (viii) the filing fees incident to the review by FINRA of the terms of sales of Shares, (ix) the fees and expenses incurred in connection with the listing of the Shares on Nasdaq, and (x) the reasonable documented out-of-pocket expenses of the Agent, including the reasonable fees, disbursements and expenses of counsel for the Agent in connection with this Agreement and the Registration Statement and ongoing services in connection with the transactions contemplated hereunder, which amount shall not exceed $100,000 in the aggregate, and (xi) the costs and expenses (including, without limitation, any damages or other amounts payable in connection with legal or contractual liability) associated with the reforming of any contracts for the sale of Shares caused by a breach of the representation contained in the second sentence of Section 1(a)(ii) hereof.

Section 5. Conditions of Agent’s Obligations. The obligations of the Agent hereunder are subject to the accuracy of the representations and warranties of the Company contained herein or in certificates of any officer of the Company delivered pursuant to the provisions hereof at each Representation Date, to the performance by the Company of its covenants and other obligations hereunder, and to the following further conditions:

(a) Effectiveness of Registration Statement and Filing of Prospectus. The Company shall have filed the Registration Statement with the Commission not earlier than three years prior to the date hereof and the Registration Statement became effective upon filing in accordance with Rule 462(e). The Company shall have filed with the Commission the Prospectus on or prior to the date of this Agreement and any subsequent Base Prospectus or Prospectus Supplement prior to any Applicable Time and related Settlement Date, as applicable, in each case in the manner and within the time period required by Rule 424(b), and each Issuer Free Writing Prospectus, if any, in the manner and within the time period required by Rule 433. No stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto has been issued under the 1933 Act, no notice of objection of the Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) has been received by the Company, no order preventing or suspending the use of any preliminary prospectus or the Prospectus or any amendment or supplement thereto has been issued and no proceedings for any of those purposes have been instituted or are pending or, to the Company’s knowledge, contemplated. The Company shall have complied with any and all requests for additional information on the part of the Commission to the reasonable satisfaction of the Agent. The Company shall have paid the required Commission filing fees relating to the Shares as specified in Section 3(a) hereof.

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(b) Opinion of Counsel for the Agent. Prior to the delivery of the first instruction to the Agent with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement, the Agent shall have received an opinion or opinions and negative assurance letter of Davis Polk & Wardwell LLP, counsel for the Agent, dated such date, in form and substance satisfactory to the Agent, and such counsel shall have received such documents as information as they may reasonably request to enable them to pass upon such matters. Such counsel may state that, insofar as such opinion involves factual matters, they have relied, to the extent they deem proper, upon certificates of officers and other representatives of the Company and its subsidiaries and certificates of public officials.

(c) Opinion of Counsel to the Company. Prior to the delivery of the first instruction to the Agent with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement, the Agent shall have received (i) an opinion of Covington & Burling LLP, outside counsel for the Company, dated such date, in form and substance reasonably satisfactory to the Agent and its counsel; (ii) an opinion of Laura A. Coruzzi, Ph.D., Senior Vice President, Intellectual Property of the Company, dated such date, in form and substance satisfactory to the Agent and its counsel; and (iii) an opinion or opinions of McDermott Will & Emery LLP, regulatory counsel for the Company, dated such date, in form and substance satisfactory to the Agent and its counsel.

With respect to the negative assurance provided by each of, Covington & Burling LLP and McDermott Will & Emery LLP, such counsel may state that their opinions and beliefs are based upon their participation in the preparation of the Registration Statement, the General Disclosure Package and the Prospectus and any amendments or supplements thereto and review and discussion of the contents thereof, but are without independent check or verification, except as specified.

(d) Accountants’ Letter. Prior to the delivery of the first instruction to the Agent with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement, the Agent shall have received a letter from PricewaterhouseCoopers LLP, independent registered public accounting firm, dated such date, in form and substance satisfactory to the Agent, containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the General Disclosure Package and the Prospectus or any amendment or supplement thereto.

(e) Officer’s Certificate on Size of ATM Program. Prior to the delivery of the first instruction to the Agent with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement, the Company shall have furnished to the Agent a certificate of an executive officer of the Company, dated such date, in a form satisfactory to the Agent, stating the minimum gross sales price per share for sales of Shares pursuant to this Agreement and the maximum number of Shares that may be issued and sold pursuant to this Agreement or, alternatively, the maximum gross proceeds from such sales, as duly authorized by the Company’s board of directors or a duly authorized committee thereof, and specify the number of Shares that have been approved for listing subject to official notice of issuance, on Nasdaq.

(f) Officer’s Certificate for the Company. Prior to the delivery of the first instruction to the Agent with respect to the sale of Shares under this ATM Equity Offering^SM Sales Agreement, there shall not have been, since the date of the latest audited financial statements included in the Registration Statement, the General Disclosure Package and the Prospectus or since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package and the Prospectus, any Material Adverse Change, and the Agent shall have received a certificate signed by an executive officer of the Company, dated such date, to the effect that (A) there has been no such Material Adverse Change, (B) the representations and warranties of the Company contained in this Agreement are true and correct with the same force and effect as though expressly made on and as of such date, (C) the Company has complied with all of the agreements and satisfied all of the conditions on its part to be performed or satisfied hereunder on or before such date and (D) no stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto has been issued under the 1933 Act, no notice of objection of the Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) has been received by the Company, no order preventing or suspending the use of any preliminary prospectus or the Prospectus or any amendment or supplement thereto has been issued and no proceedings for any of those purposes are pending or, to their knowledge, threatened by the Commission.

The officer signing and delivering such certificate may rely upon his or her knowledge as to proceedings threatened.

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(g) Listing. The Shares shall have been approved for listing, subject to official notice of issuance, on Nasdaq.

(h) Additional Documents. On the date of this ATM Equity Offering^SM Sales Agreement, counsel for the Agent shall have been furnished with such documents and opinions as they may require for the purpose of enabling them to render the opinions or make the statements requested by the Agent, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the covenants, obligations or conditions, contained herein; and all proceedings taken by the Company in connection with the issuance and sale of the Shares as contemplated herein shall be satisfactory in form and substance to the Agent and counsel for the Agent.

(i) Termination of this ATM Equity Offering^SM Sales Agreement. If any condition specified in this Section shall not have been fulfilled when and as required to be fulfilled, this ATM Equity Offering^SM Sales Agreement may be terminated by the Agent by notice to the Company at any time, and any such termination shall be without liability of any party to any other party except the provisions of Sections 1, 3(h), 4, 6, 7, 8, 10, 12, 13, 14, 15 and 16 hereof shall remain in full force and effect notwithstanding such termination.

Section 6. Indemnification.

(a) Indemnification of the Agent. The Company agrees to indemnify and hold harmless the Agent, its affiliates (as such term is defined in Rule 501(b) of the 1933 Act Regulations (each, an “Affiliate”)), selling agents, officers and directors and each person, if any, who controls the Agent within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act as follows:

(i) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or any amendment thereto), including any information deemed to be a part thereof pursuant to Rule 430B, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact included (A) in any preliminary prospectus, any Issuer Free Writing Prospectus, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) or (B) in any materials or information provided to investors by, or with the approval of, the Company in connection with the marketing of any offering of Shares (“Marketing Materials”), including any roadshow or investor presentations made to investors by the Company (whether in person or electronically), or the omission or alleged omission in any preliminary prospectus, any Issuer Free Writing Prospectus, the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) or in any Marketing Materials of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(ii) against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any Governmental Entity, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission; provided that (subject to Section 6(d) below) any such settlement is effected with the written consent of the Company;

(iii) against any and all expense whatsoever, as incurred (including the fees and disbursements of counsel chosen by the Agent), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceeding by any Governmental Entity, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under (i) or (ii) above;

provided, however, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in the Registration Statement (or any amendment thereto), including any information deemed to be a part thereof pursuant to Rule 430B, or in the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with information furnished to the Company by the Agent in writing expressly for use therein.

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(b) Indemnification of Company, Directors and Officers. The Agent agrees to indemnify and hold harmless the Company, its directors, each of its officers who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act against any and all loss, liability, claim, damage and expense described in the indemnity contained in Section 6(a) hereof, as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendment thereto), including any information deemed to be a part thereof pursuant to Rule 430B, or in the General Disclosure Package or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with the information furnished to the Company by the Agent in writing expressly for use therein.

(c) Actions against Parties; Notification. Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced, or that it reasonably expects to be commenced, against it in respect of which indemnity may be sought hereunder, but failure to so notify an indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced (through the forfeiture of substantive rights or defenses) as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. In the case of parties indemnified pursuant to Section 6(a) hereof, counsel to the indemnified parties shall be selected by the Agent, and, in the case of parties indemnified pursuant to Section 6(b) hereof, counsel to the indemnified parties shall be selected by the Company. An indemnifying party may participate at its own expense in the defense of any such action; provided, however, that in such circumstance counsel to the indemnifying party shall not (except with the prior written consent of the indemnified party) also be counsel to the indemnified party. 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. An indemnifying party will not, in any event, be liable for any settlement of any action or claim effected without its prior written consent. No indemnifying party shall, without the prior written consent of each indemnified party, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any Governmental Entity, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 6 or Section 7 hereof (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an express and unconditional release of each indemnified party, in form and substance reasonably satisfactory to such indemnified party, from all liability arising out of such litigation, investigation, proceeding 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) Settlement Without Consent if Failure to Reimburse. If at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 6(a)(ii) hereof effected without its written consent if (i) such settlement is entered into more than 60 days after receipt by such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding.

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Section 7. Contribution. If the indemnification provided for in Section 6 hereof is for any reason unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, (i) in such proportion as is appropriate to reflect the relative benefits received by the Company, on the one hand, and the Agent, on the other hand, from the applicable offering of Shares or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company, on the one hand, and the Agent, on the other hand, in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, as well as any other relevant equitable considerations.

The relative benefits received by the Company, on the one hand, and the Agent, on the other hand, in connection with the applicable offering of Shares shall be deemed to be in the same proportion as the total net proceeds from such offering (before deducting expenses) received by the Company, on the one hand, bear to the total commissions or underwriting discounts received by the Agent, on the other hand.

The relative fault of the Company, on the one hand, and the Agent, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or by the Agent and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and the Agent agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any Governmental Entity, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

Notwithstanding the provisions of this Section 7, the Agent shall not be required to contribute any amount in excess of the total commissions or underwriting discounts received by the Agent in connection with Shares placed or underwritten by it for sale to the public.

No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the 1933 Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The remedies provided for in this Section 7 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.

For purposes of this Section 7, each person, if any, who controls the Agent within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act and the Agent’s Affiliates, selling agents, officers and directors shall have the same rights to contribution as the Agent, and each director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of Section 15 of the 1933 Act or Section 20 of the 1934 Act shall have the same rights to contribution as the Company, subject in each case to the provisions hereof. Any party entitled to contribution, promptly after receipt of notice of commencement of any action against such party in respect of which a claim for contribution may be made under this Section 7, will notify any such party or parties from whom contribution may be sought, but the omission to provide such notice will not relieve that party or parties from whom contribution may be sought from any other obligation it or they may have under this Section 7, except to the extent that such failure to provide notice materially prejudiced the substantive rights or defenses of the party from which contribution is sought.

Section 8. Representations, Warranties and Agreements to Survive. All representations, warranties and agreements contained in this Agreement or in certificates of officers of the Company or any of its subsidiaries submitted pursuant hereto, shall remain operative and in full force and effect regardless of (i) any investigation made by or on behalf of the Agent or its Affiliates, selling agents, officers or directors or any person controlling the Agent, or the Company or its officers or directors, or any person controlling the Company and (ii) delivery of and payment for the Shares.

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Section 9. Termination.

(a) This ATM Equity Offering^SM Sales Agreement may be terminated for any reason, at any time, by either the Company or the Agent upon the giving of three days prior written notice to the other party hereto.

(b) The Agent may terminate a Terms Agreement to which it is a party, at any time at or prior to the Settlement Date, (i) if there has been, in such judgment of the Agent, since the time of execution of such Terms Agreement or since the respective dates as of which information is given in the Registration Statement, the General Disclosure Package or the Prospectus, any Material Adverse Change, or (ii) if 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 Agent, impracticable or inadvisable to proceed with the completion of the offering of Shares contemplated by such Terms Agreement or to enforce contracts for the sale of such Shares, or (iii) if trading in any securities of the Company has been suspended or materially limited by the Commission or Nasdaq, or (iv) if trading generally on the NYSE, the NYSE Amex or Nasdaq has 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 order of the Commission, FINRA or any other Governmental Entity, or (v) if a material disruption has occurred in commercial banking or securities settlement or clearance services in the United States or with respect to the systems of Clearstream Banking, société anonyme, or Euroclear Bank, S.A./N.V., in Europe, or (vi) if a banking moratorium has been declared by either Federal or New York authorities.

(c) In the event of any termination under this Section 9, neither party will have any liability to the other party hereto, except that (i) the Agent shall be entitled to any commissions earned in accordance with Section 2(b) hereof, (ii) if at the time of termination (a) the Agent shall own any Shares purchased by it as principal or (b) an offer to purchase any Shares has been accepted by the Company but the Settlement Date has not occurred, the covenants set forth in Section 3 hereof shall remain in effect until such Shares are resold or so delivered, as the case may be, and (iii) the covenant set forth in Section 3(h) hereof, the provisions of Section 4 hereof, the indemnity and contribution agreements set forth in Sections 6 and 7 hereof, and the provisions of Sections 8, 10, 12, 13, 14, 15 and 16 hereof shall remain in effect.

Section 10. Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Agent shall be directed to it c/o BofA Securities, Inc., One Bryant Park, New York, New York 10036, Attention: ATM Execution (email: dg.atm_execution@bofa.com), with a copy to ECM Legal (email: dg.ecm_legal@bofa.com); and notices to the Company shall be directed to it at REGENXBIO Inc., 9804 Medical Center Drive, Rockville, MD 20850, Attention: Chief Legal Officer, with a copy (which shall not constitute notice) to Covington & Burling LLP, One CityCenter, 850 Tenth Street, NW, Washington, D.C. 20001, Attention: Kerry S. Burke (email: kburke@cov.com) and Matthew C. Franker (email: mfranker@cov.com).

Section 11. No Advisory or Fiduciary Relationship. The Company acknowledges and agrees that (a) each purchase and sale of Shares pursuant to this Agreement, including the determination of the respective initial public offering prices of Shares, if any, and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the Agent, on the other hand, (b) the Agent has not assumed and will not assume any advisory or fiduciary responsibility in favor of the Company or any of its subsidiaries or other affiliates with respect to any offering of Shares or the process leading thereto (irrespective of whether the Agent has advised or is currently advising the Company or any of its subsidiaries or other affiliates on other matters) or any other obligation to the Company except the obligations expressly set forth in this Agreement, (c) the Agent and its affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company, and (d) the Agent has not provided any legal, accounting, financial, regulatory or tax advice to the Company or any other person or entity with respect to any offering of Shares and the Company has consulted its own respective legal, accounting, financial, regulatory and tax advisors to the extent it deemed appropriate.

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Section 12. Recognition of the U.S. Special Resolution Regimes.

(a) In the event that the Agent is a Covered Entity and becomes subject to a proceeding under a U.S. Special Resolution Regime, the transfer from the Agent 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.

(b) In the event that the Agent is a Covered Entity or a BHC Act Affiliate of the Agent becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights under this Agreement that may be exercised against such Agent 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 12, 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 Dodd-Frank Wall Street Reform and Consumer Protection Act and the regulations promulgated thereunder.

Section 13. Parties. This Agreement shall each inure to the benefit of and be binding upon the Agent and the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the Agent, its Affiliates and selling agents, the Company and their respective successors and the controlling persons and officers and directors referred to in Sections 6 and 7 and their heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the Agent, its Affiliates and selling agents, the Company and their respective successors, and said controlling persons and officers and directors and their heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Shares shall be deemed to be a successor by reason merely of such purchase.

Section 14. Trial by Jury. Each of the Company (on its behalf and, to the extent permitted by applicable law, on behalf of its affiliates) and the Agent 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.

Section 15. GOVERNING LAW. THIS AGREEMENT AND ANY CLAIM, CONTROVERSY OR DISPUTE ARISING UNDER OR RELATED TO THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF, THE STATE OF NEW YORK WITHOUT REGARD TO ITS CHOICE OF LAW PROVISIONS.

Section 16. Consent to Jurisdiction; Waiver of Immunity. Each of the Company and the Agent agrees that any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby (“Related Proceedings”) shall be instituted in (i) the federal courts of the United States of America located in the City and County of New York, Borough of Manhattan or (ii) the courts of the State of New York located in the City and County of New York, Borough of Manhattan (collectively, the “Specified Courts”), and irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of

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any Specified Court, as to which such jurisdiction is non-exclusive) of the Specified Courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to a party’s address set forth in Section 11 hereof shall be effective service of process upon such party for any suit, action or proceeding brought in any Specified Court. Each of the Company and the Agent irrevocably and unconditionally waives any objection to the laying of venue of any suit, action or proceeding in the Specified Courts and irrevocably and unconditionally waives and agrees not to plead or claim in any Specified Court that any such suit, action or proceeding brought in any Specified Court has been brought in an inconvenient forum.

Section 17. TIME. TIME SHALL BE OF THE ESSENCE OF THIS AGREEMENT. EXCEPT AS OTHERWISE SET FORTH HEREIN, SPECIFIED TIMES OF DAY REFER TO NEW YORK CITY TIME.

Section 18. Counterparts. This Agreement may be signed in two or more counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. The words “execution,” “signed,” “signature,” and words of like import in this Agreement or in any other certificate, agreement or document related to this Agreement, if any, shall include images of manually executed signatures transmitted by facsimile or other electronic format (including, without limitation, “pdf,” “tif” or “jpg”) and other electronic signatures (including, without limitation, DocuSign and AdobeSign). The use of electronic signatures and electronic records (including, without limitation, any contract or other record created, generated, sent, communicated, received, or stored by electronic means) shall be of the same legal effect, validity and enforceability as a manually executed signature or use of a paper-based record-keeping system to the fullest extent permitted by applicable law, including the Federal Electronic Signatures in Global and National Commerce Act, the New York State Electronic Signatures and Records Act and any other applicable law, including, without limitation, any state law based on the Uniform Electronic Transactions Act or the Uniform Commercial Code.

Section 19. Effect of Headings. The Section headings herein are for convenience only and shall not affect the construction hereof.

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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, along with all counterparts, will become a binding agreement between the Agent and the Company in accordance with its terms.

[Signature Page to Sales Agreement]

Annex I

REGENXBIO INC.

Common Stock

(par value $0.0001 per share)

TERMS AGREEMENT

BofA Securities, Inc.

One Bryant Park

New York, New York 10036

Ladies and Gentlemen:

REGENXBIO Inc., a Delaware corporation (the “Company”), proposes, on the basis of the representations and warranties, and subject to the terms and conditions, stated herein and in the ATM Equity Offering^SM Sales Agreement, dated September 1, 2023 (the “Sales Agreement”), between the Company and BofA Securities, Inc. (the “Agent”), to issue and sell to the Agent as principal for resale (the “Underwriter”), and the Underwriter agrees to purchase from the Company the shares of Common Stock specified in the Schedule A hereto (the “[Initial] Securities”) [, and to grant to the Underwriter the option to purchase the additional shares of Common Stock specified in the Schedule A hereto (the “Option Securities”, and together with the Initial Securities, the “Securities”)] on the terms specified in Schedule A hereto. Capitalized terms but and not defined herein have the respective meanings ascribed thereto in the Sales Agreement.

[The Company grants an option to the Underwriter to purchase up to an additional [•] Option Securities at the price per share set forth in Schedule A hereto, less an amount per share equal to any dividends or distributions declared by the Company and payable on the Initial Securities but not payable on the Option Securities. The option hereby granted may be exercised for 30 days after the date hereof and may be exercised in whole or in part at any time from time to time upon notice by the Underwriter to the Company setting forth the number of Option Securities as to which the Underwriter is then exercising the option and the time and date of payment and delivery for such Option Securities. Any such time and date of delivery (a “Date of Delivery”) shall be determined by the Underwriter, but shall not be later than seven full business days after the exercise of said option, nor in any event prior to the Settlement Date (as defined below). [If the option is exercised as to all or any portion of the Option Securities, each of the Underwriters, acting severally and not jointly, will purchase that proportion of the total number of Option Securities then being purchased which the number of Initial Securities set forth in Schedule A hereto opposite the name of such Underwriter bears to the total number of Initial Securities, subject, in each case, to such adjustments as BofA in its sole discretion shall make to eliminate any sales or purchases of fractional shares. For purposes of clarity, the parties hereto agree that the officers’ certificate, opinions and letter of counsel and accountants’ letter referred to in Section 3(o), (p) and (q), respectively, of the Sales Agreement are required to be delivered by or on behalf of the Company on the Settlement Date.]

Payment of the purchase price for, and delivery of certificates for, the Initial Securities shall be made at the offices of Davis Polk & Wardwell LLP, or at such other place as shall be agreed upon by the Underwriter and the Company, at 9:00 A.M. (New York City time) on the second (or third, if the pricing occurs after 4:30 P.M. (New York City time) on any given day) business day after the date hereof (unless postponed in accordance with the provisions of Section 9(c) of the Sales Agreement), or such other time not later than ten business days after such date as shall be agreed upon by the Underwriter and the Company (such time and date of payment and delivery being herein called “Settlement Date”).

In addition, in the event that any or all of the Option Securities are purchased by the Underwriter, payment of the purchase price for, and delivery of certificates for, such Option Securities shall be made at the above-mentioned offices, or at such other place as shall be agreed upon by the Underwriter and the Company, on each Date of Delivery as specified in the notice from the Underwriter to the Company.

Payment shall be made to the Company by wire transfer of immediately available funds to a bank account designated by the Company against delivery to the Underwriter.

Each of the provisions of the Sales Agreement not related solely to the Agent, as agent of the Company, is incorporated herein by reference in its entirety, and shall be deemed to be part of this Terms Agreement to the same extent as if each such provision had been set forth in full herein. Each of the representations and warranties set forth in the Sales Agreement shall be deemed to have been made at and as of the date of this Terms Agreement and , the Applicable Time and any Date of Delivery.

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, along with all counterparts, will become a binding agreement between the Underwriter and the Company in accordance with its terms.

THIS TERMS AGREEMENT AND ANY CLAIM, CONTROVERSY OR DISPUTE ARISING UNDER OR RELATED TO THIS TERMS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO ITS CHOICE OF LAW PROVISIONS.

[Signature Page to Terms Agreement]

Exhibit 5.1

REGENXBIO Inc.

9804 Medical Center Drive

Rockville, MD 20850

Ladies and Gentlemen:

We have acted as counsel to REGENXBIO Inc., a Delaware corporation (the “Company”), in connection with the registration by the Company under the Securities Act of 1933, as amended (the “Securities Act”), of the offer and sale of shares of the Company’s common stock, par value $0.0001 per share, having an aggregate offering price of up to $150,000,000 (the “Shares”), pursuant to the ATM Equity Offering^SM Sales Agreement, dated September 1, 2023, among the Company and BofA Securities, Inc., as sales agent (the “Sales Agreement”). The offer and sale of the Shares are being registered under the Securities Act pursuant to the Company’s Registration Statement on Form S-3 (File No. 333-269086), which was filed with the Securities and Exchange Commission on December 30, 2022 (such registration statement is herein referred to as the “Registration Statement”).

We have reviewed the Sales Agreement, the Registration Statement and the prospectus, dated December 30, 2022, as supplemented by a prospectus supplement dated September 1, 2023, with respect to the offer and sale of the Shares, as filed with the Securities and Exchange Commission on September 1, 2023. We have also reviewed such corporate records, certificates and other documents, and such questions of law, as we have considered necessary or appropriate for the purposes of this opinion.

We have assumed that all signatures are genuine, that all documents submitted to us as originals are authentic and that all copies of documents submitted to us conform to the originals.

We have relied as to certain matters on information obtained from public officials, officers of the Company and other sources believed by us to be responsible.

Based upon the foregoing, we are of the opinion that the Shares have been duly authorized, and when issued and sold by the Company pursuant to the terms of the Sales Agreement and upon receipt by the Company of full payment therefor in accordance with the Sales Agreement, will be validly issued, fully paid and non-assessable.

We are members of the bar of the District of Columbia. We do not express any opinion herein on any laws other than the Delaware General Corporation Law.

REGENXBIO Inc.

September 1, 2023

Page 2

We hereby consent to the filing of this opinion as Exhibit 5.1 to the Company’s Current Report on Form 8-K dated the date hereof related to the offering of the Shares. We also hereby consent to the reference to our firm under the heading “Legal Matters” in the prospectus constituting part of the Registration Statement. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.