XLO Xilio Therapeutics Inc

Exhibit 1.1

XILIO THERAPEUTICS, INC.

SHARES OF

COMMON STOCK

SALES AGREEMENT

March 11, 2025

LEERINK PARTNERS LLC

1301 Avenue of the Americas, 5^th Floor

New York, New York 10019

Ladies and Gentlemen:

Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with Leerink Partners LLC (“Leerink Partners”), as follows:

1. Issuance and Sale of Shares. The Company agrees that, from time to time during the term of this Agreement, on the terms and subject to the conditions set forth herein, it may issue and sell through Leerink Partners, acting as agent, shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), subject to the limitations set forth in Section 5(c). Notwithstanding anything to the contrary contained herein, the parties hereto agree that compliance with the limitation set forth in this Section 1 on the number of shares of Common Stock issued and sold under this Agreement shall be the sole responsibility of the Company, and Leerink Partners shall have no obligation in connection with such compliance. The issuance and sale of the Shares through Leerink Partners will be effected pursuant to the Registration Statement (as defined below) that has been or will be filed by the Company and after such Registration Statement has been declared effective by the Securities and Exchange Commission (the “Commission”), although nothing in this Agreement shall be construed as requiring the Company to use the Registration Statement (as defined below) to issue the Shares.

The Company has filed, or will file, in accordance with the provisions of the Securities Act of 1933, as amended, and the rules and regulations thereunder (collectively, the “Securities Act”), with the Commission a shelf registration statement on Form S-3, including a base prospectus, relating to certain securities, including the Common Stock, to be issued from time to time by the Company, and which incorporates by reference documents that the Company has filed or will file in accordance with the provisions of the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (collectively, the “Exchange Act”). The Company has prepared, or will prepare, as applicable, a prospectus or a prospectus supplement to the base prospectus included as part of the registration statement, which prospectus or prospectus supplement relates to the Shares to be issued from time to time by the Company (“Prospectus Supplement”). The Company may file one or more additional registration statements from time to time that may contain a prospectus relating to the Shares and/or a base prospectus and related prospectus supplement relating to the Shares, which in each case shall be a Prospectus Supplement. Except where the context otherwise requires, such registration statement, and any post-effective

amendment thereto, as amended when it becomes effective, including all documents filed as part thereof or incorporated by reference therein, and including any information contained in a Prospectus (as defined below) subsequently filed with the Commission pursuant to Rule 424(b) under the Securities Act or deemed to be a part of such registration statement pursuant to Rule 430B or 462(b) of the Securities Act, or any subsequent registration statement on Form S-3 filed pursuant to Rule 415(a)(6) under the Securities Act by the Company to cover any Shares, is herein called the “Registration Statement.” The Prospectus Supplement, including all documents incorporated therein by reference, as it may be supplemented by one or more Prospectus Supplements, if any, in the form in which such Prospectus Supplements have most recently been filed by the Company with the Commission pursuant to Rule 424(b) under the Securities Act, together with any “issuer free writing prospectus,” as defined in Rule 433 of the Securities Act regulations (“Rule 433”), relating to the Shares that (i) is consented to by Leerink Partners, hereinafter referred to as a “Permitted Free Writing Prospectus,” (ii) is required to be filed with the Commission by the Company or (iii) is exempt from filing pursuant to Rule 433(d)(5)(i), 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), is herein called the “Prospectus.” Any reference herein to the Registration Statement, the Prospectus or any amendment or supplement thereto shall be deemed to refer to and include the documents incorporated by reference therein, and any reference herein to the terms “amend,” “amendment” or “supplement” with respect to the Registration Statement or the Prospectus shall be deemed to refer to and include the filing after the execution hereof of any document with the Commission deemed to be incorporated by reference therein. For purposes of this Agreement, all references to the Registration Statement, the Prospectus or to any amendment or supplement thereto shall be deemed to include any copy filed with the Commission pursuant to the Electronic Data Gathering Analysis and Retrieval System (“EDGAR”). The Company’s obligations under this Agreement to furnish, provide, deliver or make available (and all other references of like import) copies of any document shall be deemed satisfied if the same is filed with the Commission through EDGAR.

2. Agency Transactions. Each time that the Company wishes, in its sole discretion, to issue and sell the Shares hereunder through Leerink Partners, acting as agent (each, an “Agency Transaction”), it will notify Leerink Partners by email notice (or other method mutually agreed to in writing by the parties) (a “Placement Notice”) containing the parameters in accordance with which it desires the Shares to be sold, which shall at a minimum include the number of Shares to be issued, the time period during which sales are requested to be made, any limitation on the number of Shares that may be sold in any one Trading Day (as defined in Section 3) and any minimum price below which sales may not be made, a form of which containing such minimum sales parameters necessary is attached hereto as Schedule 1. The Placement Notice shall originate from any of the individuals authorized to act on behalf of the Company set forth on Schedule 2 (with a copy to each of the other individuals from the Company listed on such schedule) and shall be addressed to each of the individuals from Leerink Partners set forth on Schedule 2, as such Schedule 2 may be amended from time to time by sending a written notice containing a revised Schedule 2 to the other party in the manner provided in Section 12 (including by email correspondence to each of the individuals of the Company set forth on Schedule 2, if receipt of such correspondence is actually acknowledged by any of the individuals to whom the notice is sent, other than via auto-reply). The Placement Notice shall be effective upon receipt by Leerink

- 2 -

Partners unless and until (i) in accordance with the notice requirements set forth in Section 4, Leerink Partners declines to accept the terms contained therein for any reason, in its sole discretion, within two Trading Days (as defined below) of the date Leerink Partners receives the Placement Notice, in its sole discretion, (ii) the entire amount of the Shares have been sold, (iii) in accordance with the notice requirements set forth in Section 4, the Company suspends or terminates the Placement Notice for any reason in its sole discretion, (iv) the Company issues a subsequent Placement Notice with parameters superseding those on the earlier dated Placement Notice, or (v) this Agreement has been terminated under the provisions of Section 11. The amount of any discount, commission or other compensation to be paid by the Company to Leerink Partners in connection with the sale of the Shares shall be calculated in accordance with the terms set forth in Schedule 3. It is expressly acknowledged and agreed that neither the Company nor Leerink Partners will have any obligation whatsoever with respect to an Agency Transaction or any Shares unless and until the Company delivers a Placement Notice to Leerink Partners and Leerink Partners does not decline such Placement Notice pursuant to the terms set forth above, and then only upon the terms specified therein and herein. In the event of a conflict between the terms of this Agreement and the terms of a Placement Notice, the terms of the Placement Notice will control.

3. Sale of Shares by Leerink Partners.

(a) On the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, including Section 5(c), upon the Company’s delivery of a Placement Notice, and unless the sale of the Shares described therein has been declined, suspended, or otherwise terminated in accordance with the terms of this Agreement, Leerink Partners, for the period specified in the Placement Notice, will use its commercially reasonable efforts consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of the Nasdaq Global Select Market (“Nasdaq”) to sell such Shares up to the amount specified, and otherwise in accordance with the terms of such Placement Notice. Leerink Partners will provide written confirmation to the Company (including by email correspondence to each of the individuals of the Company set forth on Schedule 2, if receipt of such correspondence is actually acknowledged by any of the individuals to whom the notice is sent, other than via auto-reply) no later than the opening of the Trading Day immediately following the Trading Day on which it has made sales of Shares hereunder setting forth the number of Shares sold on such day, the volume-weighted average price of the Shares sold, and the Net Proceeds (as defined below) payable to the Company. Subject to the terms and conditions of the applicable Placement Notice, Leerink Partners may sell Shares by any method permitted by law deemed to be an “at the market offering” as defined in Rule 415(a)(4) of the Securities Act, including without limitation sales made through Nasdaq or on or through any other existing trading market for the Common Stock. If expressly authorized to do so by the Company in a Placement Notice, Leerink Partners may also sell Shares in negotiated transactions. Except as may be otherwise agreed by the Company and Leerink Partners, Leerink Partners shall not purchase Shares on a principal basis pursuant to this Agreement unless the Company and Leerink Partners enter into a separate written agreement setting forth the terms of such sale. The Company acknowledges and agrees that (i) there can be no assurance that Leerink Partners will be successful in selling Shares, and (ii) Leerink Partners will incur no liability or obligation to the Company or any other person or entity if it does not sell Shares for any reason other than a failure by Leerink Partners to use its commercially reasonable efforts consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of Nasdaq to sell such Shares as required under this Section 3. For the purposes hereof, “Trading Day” means any day on which the Company’s Common Stock is purchased and sold on the principal market on which the Common Stock is listed or quoted.

- 3 -

(b) Notwithstanding any other provision of this Agreement, the Company shall not offer, sell or deliver, or request the offer or sale, of any Shares pursuant to this Agreement and, by notice to Leerink Partners given by telephone (confirmed promptly by email), shall cancel any instructions for the offer or sale of any Shares, and Leerink Partners shall not be obligated to offer or sell any Shares, during any period in which the Company is, or would reasonably be deemed to be, in possession of material non-public information.

4. Suspension of Sales.

(a) The Company or Leerink Partners may, upon notice to the other party in writing (including by email correspondence to each of the individuals of the other party set forth on Schedule 2, if receipt of such correspondence is actually acknowledged by any of the individuals to whom the notice is sent, other than via auto-reply) or by telephone (confirmed immediately by verifiable facsimile transmission or email correspondence to each of the individuals of the other party set forth on Schedule 2), suspend any sale of Shares; provided, however, that such suspension shall not affect or impair either party’s obligations with respect to any Shares sold hereunder prior to the receipt of such notice. While a suspension is in effect, any obligation under Sections 7(m), 7(n), 7(o) and 7(p) with respect to the delivery of certificates, opinions, or comfort letters to Leerink Partners shall be waived. Each of the parties agrees that no such notice under this Section 4 shall be effective against the other unless it is made to one of the individuals named on Schedule 2 hereto, as such schedule may be amended from time to time.

(b) If either Leerink Partners or the Company has reason to believe that the exemptive provisions set forth in Rule 101(c)(1) of Regulation M under the Exchange Act are not satisfied with respect to the Common Stock, it shall promptly notify the other party, and Leerink Partners may, at its sole discretion, suspend sales of the Shares under this Agreement.

(c) Notwithstanding any other provision of this Agreement, after the Commission declares the Registration Statement effective, during any period in which the Registration Statement is no longer effective under the Securities Act, the Company shall promptly notify Leerink Partners, the Company shall not request the sale of any Shares, and Leerink Partners shall not be obligated to sell or offer to sell any Shares.

5. Settlement.

(a) Settlement of Shares. Unless otherwise specified in the applicable Placement Notice, settlement for sales of Shares will occur on the first (1^st) Trading Day (or such earlier day as is industry practice for regular-way trading) following the date on which such sales are made (each, a “Settlement Date” and the first such Settlement Date, the “First Delivery Date”). The amount of proceeds to be delivered to the Company on a Settlement Date against receipt of the Shares sold (the “Net Proceeds”) will be equal to the aggregate sales price received by Leerink

- 4 -

Partners at which such Shares were sold, after deduction for (i) Leerink Partners’ commission, discount or other compensation for such sales payable by the Company pursuant to Section 2 hereof, (ii) any other amounts due and payable by the Company to Leerink Partners hereunder pursuant to Section 7(g) (Expenses) hereof, and (iii) any transaction fees imposed by any governmental or self-regulatory organization in respect of such sales that are paid by Leerink Partners.

(b) Delivery of Shares. On or before each Settlement Date, the Company will, or will cause its transfer agent to, electronically transfer the Shares being sold by crediting Leerink Partners’ or its designee’s account (provided Leerink Partners shall have given the Company written notice of such designee prior to the Settlement Date) at The Depository Trust Company through its Deposit and Withdrawal at Custodian System (“DWAC”) or by such other means of delivery as may be mutually agreed upon by the parties hereto which in all cases shall be freely tradeable, transferable, registered shares in good deliverable form. Leerink Partners shall be responsible for providing DWAC instructions or instructions for delivery by other means with respect to the Shares being sold. On each Settlement Date, Leerink Partners will deliver the related Net Proceeds in same day funds to an account designated by the Company on, or prior to, the Settlement Date. In addition to and in no way limiting the rights and obligations set forth in Section 9(a) (Indemnification and Contribution) hereto, the Company agrees that if the Company or its transfer agent (if applicable), defaults in its obligation to deliver duly authorized, freely tradeable, transferable, registered Shares in good deliverable form on a Settlement Date (other than as a result of a failure by Leerink Partners to provide instructions for delivery), the Company will (i) take all necessary action to cause the full amount of any Net Proceeds that were delivered to the Company’s account with respect to such settlement, together with any costs incurred by Leerink Partners and/or its clearing firm in connection with recovering such Net Proceeds, to be immediately returned to Leerink Partners or its clearing firm by wire transfer of immediately available funds to an account designated by Leerink Partners or its clearing firm, (ii) indemnify and hold Leerink Partners and its clearing firm, harmless against any loss, claim, damage, or reasonable and documented expense (including reasonable and documented legal fees and expenses), as incurred, arising out of or in connection with such default by the Company and (iii) pay to Leerink Partners (without duplication) any commission, discount, or other compensation to which it would otherwise have been entitled absent such default.

(c) Limitations on Offering Size. Under no circumstances shall the Company cause or request the offer or sale of any Shares if, after giving effect to the sale of such Shares, the aggregate number or gross sales proceeds of Shares sold pursuant to this Agreement would exceed the lesser of: (i) the number or dollar amount of shares of Common Stock registered pursuant to, and available for offer and sale under, the Registration Statement pursuant to which the offering of Shares is being made, (ii) the number of authorized but unissued shares of Common Stock of the Company (less shares of Common Stock issuable upon exercise, conversion or exchange of any outstanding securities of the Company or otherwise reserved from the Company’s authorized capital stock), (iii) the number or dollar amount of shares of Common Stock permitted to be offered and sold by the Company under Form S-3 (including General Instruction I.B.6. thereof, if such instruction is applicable), (iv) the number or dollar amount of Shares that the Company’s board of directors or a duly authorized committee thereof is authorized to issue and sell from time to time, and notified to Leerink Partners in writing or (v) the dollar amount of Shares for which the

- 5 -

Company has filed the Prospectus Supplement. Under no circumstances shall the Company cause or request the offer or sale of any Shares pursuant to this Agreement at a price lower than the minimum price authorized from time to time by the Company’s board of directors or a duly authorized committee thereof, and notified to Leerink Partners in writing. Notwithstanding anything to the contrary contained herein, the parties hereto acknowledge and agree that compliance with the limitations set forth in this Section 5(c) on the number or dollar amount of Shares that may be issued and sold under this Agreement from time to time shall be the sole responsibility of the Company, and that Leerink Partners shall have no obligation in connection with such compliance.

6. Representations and Warranties of the Company. The Company represents and warrants to, and agrees with, Leerink Partners that, unless such representation, warranty or agreement specifies a different time, as of (i) the date of this Agreement, (ii) each Time of Sale (as defined below), (iii) each Settlement Date, and (iv) each Bring-Down Date (as defined below) (each such date included in (i) through (iv) above, a “Representation Date”):

(a) Compliance with Registration Requirements. Prior to the delivery of the first Placement Notice, the Registration Statement and any Rule 462(b) Registration Statement have been declared effective by the Commission under the Securities Act. The Company has complied to the Commission’s satisfaction with all requests of the Commission for additional or supplemental information. No stop order suspending the effectiveness of the Registration Statement or any Rule 462(b) Registration Statement is in effect and no proceedings for such purpose have been instituted or are pending or, to the knowledge of the Company, contemplated or threatened by the Commission. The Company meets the requirements for use of Form S-3 under the Securities Act. The sale of the Shares hereunder meets the requirements of General Instruction I.B.1 or I.B.6., as applicable, of Form S-3.

(b) No Misstatement or Omission. The Prospectus when filed complied and, as amended or supplemented, if applicable, will comply in all material respects with the requirements of the Securities Act. Each of the Registration Statement, any Rule 462(b) Registration Statement, the Prospectus and any post-effective amendments or supplements thereto, at the time it became effective or its date, as applicable, complied and as of each Representation Date, complied and will comply in all material respects with the Securities Act and did not and, as of each Representation Date, did not and will not contain any 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. The Prospectus, as amended or supplemented, as of its date, did not and, as of each Representation Date, will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The representations and warranties set forth in the two immediately preceding sentences do not apply to statements in or omissions from the Registration Statement, any Rule 462(b) Registration Statement, or any post-effective amendment thereto, or the Prospectus, or any amendments or supplements thereto, made in reliance upon and in conformity with information relating to the Agent’s Information (defined below). As used herein, “Time of Sale” means with respect to each offering of Shares pursuant to this Agreement, the time of Leerink Partners’ initial entry into contracts with purchasers for the sale of such Shares.

- 6 -

(c) Offering Materials Furnished to Leerink Partners. The Company has delivered to Leerink Partners one complete copy of the Registration Statement and a copy of each consent and certificate of experts filed as a part thereof, and conformed copies of the Registration Statement (without exhibits) and the Prospectus, as amended or supplemented, in such quantities and at such places as Leerink Partners has reasonably requested. The Registration Statement, the Prospectus and any Permitted Free Writing Prospectus (to the extent any such Permitted Free Writing Prospectus was required to be filed with the Commission) delivered to Leerink Partners for use in connection with the public offering of the Shares contemplated herein have been and will be identical to the versions of such documents transmitted to the Commission for filing via EDGAR, except to the extent permitted by Regulation S-T.

(d) Not an Ineligible Issuer. The Company currently is not an “ineligible issuer,” as defined in Rule 405 under the Securities Act. The Company agrees to notify Leerink Partners promptly upon the Company becoming an “ineligible issuer.”

(e) Distribution of Offering Material By the Company. The Company has not distributed and will not distribute, prior to the completion of Leerink Partners’ distribution of the Shares, any offering material in connection with the offer and sale of the Shares other than the Prospectus or the Registration Statement.

(f) Incorporation and 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 or lease its property and to conduct its business as described in each of the Registration Statement and the Prospectus 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 be in good standing would not reasonably be expected to, singly or in the aggregate, have a Material Adverse Change (as defined below) on the Company and its subsidiaries, taken as a whole.

(g) Incorporation and Good Standing of the Company’s Subsidiaries. Each subsidiary of the Company has been duly incorporated, organized or formed, is validly existing as a corporation or other business entity in good standing under the laws of the jurisdiction of its incorporation, organization or formation, has the corporate or other business entity power and authority to own or lease its property and to conduct its business as described in each of the Registration Statement and the Prospectus 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 be in good standing would not, singly or in the aggregate, reasonably be expected to have a Material Adverse Change on the Company and its subsidiaries, taken as a whole; all of the issued shares of capital stock or other equity interests of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, free and clear of all liens, encumbrances, equities or claims. The Company does not own or control, directly or indirectly, any corporation, association or other entity other than the subsidiaries listed in Exhibit 21.1 to the Company’s Annual Report on Form 10-K for the most recently ended fiscal year and other than (i) those subsidiaries not required to be listed on Exhibit 21.1 by Item 601 of Regulation S-K under the Exchange Act and (ii) those subsidiaries formed since the last day of the most recently ended fiscal year.

- 7 -

(h) The Sales Agreement. This Agreement has been duly authorized, executed and delivered by, and is a valid and binding agreement of, the Company, enforceable in accordance with its terms, except as rights to indemnification hereunder may be limited by applicable law and except as the enforcement hereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles. This Agreement conforms in all material respects to the descriptions thereof in the Registration Statement and the Prospectus.

(i) Capital Stock Matters. The capital stock of the Company conforms in all material respects as to legal matters to the description thereof contained in each of the Registration Statement and the Prospectus.

(j) Authorization of the Common Stock. The shares of Common Stock outstanding prior to the issuance of the Shares have been duly authorized and are validly issued, fully paid and non-assessable. The Shares, when issued and delivered, will be duly authorized for issuance and sale pursuant to this Agreement and, when issued and delivered by the Company against payment therefor pursuant to this Agreement, will be duly authorized, validly issued, fully paid and nonassessable, free and clear of any pledge, lien, encumbrance, security interest or other claim, and the issuance and sale of the Shares by the Company is not subject to preemptive or other similar rights arising by operation of law, under the organizational documents of the Company or under any agreement to which the Company or any subsidiary is a party or otherwise, except for those that have otherwise been validly waived.

(k) Non-Contravention of Existing Instruments; No Further Authorizations or Approvals Required. 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 the 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 as would not, singly or in the aggregate, reasonably be expected to have a Material Adverse Change 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. No consent, approval, authorization or order of, or qualification with, any governmental body, agency or court is required 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 (“FINRA”) or Nasdaq in connection with the offer and sale of the Shares.

- 8 -

(l) No Material Adverse Change. There has not occurred any Material Adverse Change, or any development that would reasonably be expected to result in a Material Adverse Change, in the condition, financial or otherwise, or in the earnings, business, prospects or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Registration Statement and Prospectus. Subsequent to the date as of which information is given in the Prospectus, (i) there has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, business, operations or prospects, whether or not arising from transactions in the ordinary course of business, of the Company and its subsidiaries, considered as one entity (any such change is called a “Material Adverse Change”), (ii) the Company and its subsidiaries, taken as a whole, have not incurred any material liability or obligation, direct or contingent, nor entered into any material transaction; (iii) the Company has not purchased any of its outstanding capital stock (other than from its employees or other service providers in connection with the termination of the service pursuant to plans or agreements, as applicable), nor declared, paid or otherwise made any dividend or distribution of any kind on its capital stock other than ordinary and customary dividends; and (iv) there has not been any material change in the capital stock, short-term debt or long-term debt of the Company and its subsidiaries, taken as a whole, except in each case as described in each of the Registration Statement and the Prospectus.

(m) No Material Actions or Proceedings. There are no legal or governmental proceedings pending or, to the Company’s knowledge, threatened to which the Company or any of its subsidiaries is a party or to which any of the properties of the Company or any of its subsidiaries is subject (i) other than proceedings described in each of the Registration Statement, and the Prospectus and proceedings that would not, singly or in the aggregate, have a Material Adverse Change 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 each of the Registration Statement and the Prospectus or (ii) that are required to be described in the Registration Statement or the Prospectus and are not so described in all material respects; and there are no contracts or other documents to which the Company or its subsidiaries are subject or bound that are required to be described in the Registration Statement or the Prospectus or to be filed as exhibits to the Registration Statement that are not described in all material respects or filed as required.

(n) Company Not an “Investment Company.” The Company is not, and immediately after giving effect to the offering and sale of the Shares and the application of the proceeds thereof as described in 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 “Investment Company Act”).

(o) Compliance with Environmental Laws. The Company and each of 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 have a Material Adverse Change on the Company and its subsidiaries, taken as a whole. There are no costs or liabilities associated with Environmental

- 9 -

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) which would, singly or in the aggregate, reasonably be expected to have a Material Adverse Change on the Company and its subsidiaries, taken as a whole.

(p) No Applicable Registration or Other Similar Rights. 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 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, except those contracts, agreements and understandings described in the Registration Statement and the Prospectus, all of which have been validly waived or complied with in connection with the issuance and sale of the Shares contemplated hereby.

(q) No Unlawful Contributions or Other Payments. (i) None of the Company or any of its subsidiaries or controlled affiliates, or any director, officer or employee thereof, or, to the Company’s knowledge, any agent or representative of the Company or of any of its subsidiaries or controlled affiliates, has taken or will take any action in furtherance of an offer, payment, promise to pay, or authorization or approval of the payment, giving or receipt 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) in order to improperly influence official action, or to any person in violation of any applicable anti-corruption laws; (ii) the Company and each of its subsidiaries and controlled affiliates have conducted their businesses in compliance with applicable anti-corruption laws and instituted at the time of the offering and will maintain policies and procedures reasonably designed to promote and achieve compliance with such laws and with the representations and warranties contained herein; and (iii) neither the Company nor any of 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.

(r) Compliance with Money Laundering Laws. The operations of the Company and each of its subsidiaries are and have been conducted at all times in material compliance 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 each of 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 having jurisdiction over the Company or its subsidiaries (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.

- 10 -

(s) Compliance with OFAC. (i) None of the Company, any of its subsidiaries, or any director, officer, or employee thereof, or, to the Company’s knowledge, 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 one or more Persons that are: (A) the subject of any sanctions administered or enforced by the U.S. Department of the 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”), or (B) located, organized or resident in a country or territory that is the subject of Sanctions (including, without limitation, Crimea, the so-called Donetsk People’s Republic, the so-called Luhansk People’s Republic, Cuba, Iran, North Korea and Syria); (ii) 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: (A) 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 of Sanctions; or (B) 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); (iii) the Company and each of its subsidiaries have not knowingly engaged in, are not now knowingly engaged in, and will not knowingly 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 of Sanctions.

(t) Title to Real and Personal Property. The Company and each of its subsidiaries have good and marketable title to all real property owned by them and good and marketable title to all personal property owned by them, in each case, which is material to the business of the Company and its subsidiaries, and in each case, free and clear of all liens, encumbrances and defects, except such as are described in each of the Registration Statement and the Prospectus or such as do not materially affect the value of such property and do not interfere in any material respect with the use made and proposed to be made of such property by the Company and its subsidiaries; and any real property and buildings held under lease by the Company and its subsidiaries are held by them, as applicable, under valid, subsisting and enforceable leases with such exceptions as are not material and do not interfere in any material respect with the use made and proposed to be made of such property and buildings by the Company and its subsidiaries.

(u) Intellectual Property. (i) The Company and its subsidiaries own or have a valid license to all pending patent applications and issued patents, inventions, copyrights, know how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures), trademarks, service marks and trade names (collectively, “Intellectual Property Rights”) used in or reasonably necessary to the conduct of their businesses in the manner described in the Registration Statement and Prospectus; (ii) the Intellectual Property Rights owned by the Company and its subsidiaries and, to the Company’s knowledge, the Intellectual Property Rights licensed to the Company and its subsidiaries, are valid, subsisting and enforceable, and there is no pending or, to the Company’s knowledge, threatened action, suit, proceeding or claim by others challenging the validity, scope or enforceability of any such Intellectual Property Rights; (iii) neither the Company nor any of its subsidiaries has received any

- 11 -

notice alleging any infringement, misappropriation or other violation of Intellectual Property Rights which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a Material Adverse Change on the Company and its subsidiaries, taken as a whole, and, to the Company’s knowledge, none of the licensors, in relation to the Intellectual Property Rights licensed to the Company and its subsidiaries, have received any notice alleging any infringement, misappropriation or other violation of Intellectual Property Rights licensed to the Company and its subsidiaries which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a Material Adverse Change on the Company and its subsidiaries, taken as a whole; (iv) to the Company’s knowledge, no third party is infringing, misappropriating or otherwise violating, or has infringed, misappropriated or otherwise violated, any Intellectual Property Rights owned by the Company or any of its subsidiaries, and any Intellectual Property Rights licensed to the Company and its subsidiaries, that would materially adversely affect the Company and its subsidiaries, taken as a whole; (v) neither the Company nor any of its subsidiaries infringes, misappropriates or otherwise violates, or has infringed, misappropriated or otherwise violated, any Intellectual Property Rights of a third party in any material respect; (vi) all employees or contractors engaged in the development of material Intellectual Property Rights on behalf of the Company or any subsidiary of the Company have executed an invention assignment agreement whereby such employees or contractors presently assign all of their right, title and interest in and to such Intellectual Property Rights to the Company or the applicable subsidiary, and to the Company’s knowledge no such agreement has been breached or violated; (vii) the Company and its subsidiaries use, and have used, commercially reasonable efforts to appropriately maintain all information intended to be maintained as a trade secret; and (viii) all employees or contractors engaged in the development of material trade secrets on behalf of the Company or any subsidiary of the Company have executed a confidentiality agreement with the Company or any subsidiary of the Company.

(v) IT Systems. (i) The Company and its subsidiaries use and have used any and all software and other materials distributed under a “free,” “open source,” or similar licensing model (including but not limited to the MIT License, Apache License, GNU General Public License, GNU Lesser General Public License and GNU Affero General Public License) (“Open Source Software”) in compliance with all license terms applicable to such Open Source Software; and (ii) neither the Company nor any of its subsidiaries uses or distributes or has used or distributed any Open Source Software in any manner that requires or has required (A) the Company or any of its subsidiaries to permit reverse engineering of any software code or other technology owned by the Company or any of its subsidiaries or (B) any software code or other technology owned by the Company or any of its subsidiaries to be (1) disclosed or distributed in source code form, (2) licensed for the purpose of making derivative works or (3) redistributed at no charge.

(w) Privacy Laws. (i) The Company and each of its subsidiaries have complied and are presently in material compliance with all internal and external privacy policies, contractual obligations, industry standards, applicable laws, statutes, judgments, orders, rules and regulations of any court or arbitrator or other governmental or regulatory authority with jurisdiction over the Company, in each case, relating to the collection, use, transfer, import, export, storage, protection, disposal and disclosure by the Company or any of its subsidiaries of personal, personally identifiable, household, sensitive, confidential or regulated data (“Data Security Obligations”, and such data, “Data”); (ii) the Company has not received any notification of or complaint

- 12 -

regarding and is unaware of any other facts that, singly or in the aggregate, would reasonably indicate material non-compliance with any Data Security Obligation; and (iii) there is no action, suit or proceeding by or before any court or governmental agency, authority or body pending or, to the Company’s knowledge, threatened alleging material non-compliance with any Data Security Obligation. The Company and each of its subsidiaries have taken reasonable technical, physical and organizational measures to protect the information technology systems and Data used in connection with the operation of the Company’s and its subsidiaries’ businesses. Without limiting the foregoing, the Company and its subsidiaries have used reasonable efforts to establish and maintain, and have established, maintained, implemented and complied with, reasonable information technology, information security, cyber security and data protection controls, policies and procedures, including oversight, access controls, technological and physical safeguards and business continuity/disaster recovery and security plans that are designed to protect against and prevent breach, destruction, loss, unauthorized distribution, use, access, disablement, misappropriation or modification, or other compromise or misuse of or relating to any information technology system or Data used in connection with the operation of the Company’s and its subsidiaries’ businesses (“Breach”). To the Company’s knowledge, there has been no such Breach, and the Company and its subsidiaries have no knowledge of any event or condition that would reasonably be expected to result in any such Breach.

(x) No Labor Disputes. No material labor dispute with the employees of the Company or any of its subsidiaries exists, or, to the knowledge of the Company, is imminent; and the Company is not aware of any existing, threatened or imminent labor disturbance by the employees of any of its principal suppliers, manufacturers or contractors that could, singly or in the aggregate, have a Material Adverse Change on the Company and its subsidiaries, taken as a whole.

(y) 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 Company’s reasonable judgment, are prudent and customary in the businesses in which they are engaged; neither the Company nor any of its subsidiaries has been refused any insurance coverage sought or applied for; and neither the Company nor any of its subsidiaries has any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage from similar insurers as may be necessary to continue its business at a cost that would not reasonably be expected to, singly or in the aggregate, have a Material Adverse Change on the Company and its subsidiaries, taken as a whole.

(z) Compliance with Health Care Laws. The Company has operated at all times and is currently in compliance in all material respects with all applicable statutes, rules and regulations of the U.S. Food and Drug Administration (the “FDA”), and applicable foreign regulatory authorities, including the European Medicines Agency and the UK Medicines & Healthcare products Regulatory Agency (collectively, the “Regulatory Authorities”), except where failure to be in compliance would not be expected reasonably to have a Material Adverse Change on the Company and its subsidiaries, taken as a whole. For purposes of this Agreement, “Health Care Laws” means: (i) the Federal Food, Drug, and Cosmetic Act and the regulations promulgated thereunder; (ii) all applicable federal, state, local and foreign health care laws, including, without limitation, the U.S. Anti-Kickback Statute (42 U.S.C. Section 1320a-7b(b)), the Civil Monetary Penalties Law (42 U.S.C. § 1320a-7a), the U.S. Civil False Claims Act (31 U.S.C. Section 3729

- 13 -

et seq.), all applicable federal, state, local and all foreign criminal laws relating to health care fraud and abuse, including but not limited to the U.S. False Statements Law (42 U.S.C. Section 1320a-7b(a)), 18 U.S.C. Sections 286 and 287, and the health care fraud criminal provisions under the U.S. Health Insurance Portability and Accountability Act of 1996 (“HIPAA”) (42 U.S.C. Section 1320d et seq.), the U.S. Physician Payments Sunshine Act (42 U.S.C. Section 1320a-7h), the exclusions law, the statutes and regulations of applicable government funded or sponsored healthcare programs, and the regulations promulgated pursuant to such statutes; (iii) HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act (42 U.S.C. Section 17921 et seq.), and the regulations promulgated thereunder and any state or non-U.S. counterpart thereof to which the Company is subject, the purpose of which is to protect the privacy of individuals or prescribers; (iv) the Patient Protection and Affordable Care Act of 2010, as amended by the Health Care and Education Reconciliation Act of 2010, the regulations promulgated thereunder; and (v) all other local, state, federal, national, supranational and foreign laws, relating to the regulation of the Company and the ownership, testing, development, manufacture, packaging, processing, use, distribution, marketing, labeling, promotion, sale, offer for sale, storage, import, export or disposal of any product under development, manufactured or distributed by the Company.

(aa) Tests and Preclinical and Clinical Trials. (i) the preclinical studies, research tests and clinical trials conducted by or on behalf of or sponsored by the Company or in which the Company has participated that are described or referred to in the Registration Statement and the Prospectus, were, and if still pending are, being conducted in all material respects in accordance with standard medical and experimental protocols, procedures and controls pursuant to all applicable Health Care Laws, the rules and regulations of the Regulatory Authorities and current Good Clinical Practices and Good Laboratory Practices; (ii) the descriptions of the results of such studies and trials contained in the Registration Statement or the Prospectus are accurate in all material respects and fairly present the data derived from such trials and studies; (iii) the Company has no knowledge of any other preclinical studies, research tests or clinical trials not described in the Registration Statement and the Prospectus, the results of which are materially inconsistent with or call into question in any material respect the results described or referred to in the Registration Statement and the Prospectus; (iv) the Company has provided Leerink Partners with all substantive and material written notices, correspondence and summaries of all other communications provided to the Company or its subsidiaries from the Regulatory Authorities; and (v) the Company has not received any written and material notices, correspondence or other communications from any Regulatory Authority requiring or threatening the termination, material modification or suspension of any studies or trials that are described in the Registration Statement and the Prospectus or the results of which are referred to in the Registration Statement and the Prospectus, and, to the Company’s knowledge, there are no reasonable grounds for the same.

(bb) Health Care Laws. (i) Except as would not, singly or in the aggregate, have a Material Adverse Change on the Company and its subsidiaries, taken as a whole, the Company has filed, obtained, maintained or submitted all reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments as required by any Health Care Laws, and, all such reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments were timely, complete, accurate and not misleading in all material respects on the date filed (or were corrected or supplemented by a subsequent submission); (ii) the

- 14 -

Company has not received written notice of any claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any court or arbitrator or Regulatory Authority or other governmental entity alleging that the Company is in material violation of any Health Care Laws, including, without limitation, any FDA Form 483, notice of adverse finding, warning letter, untitled letter from the FDA or any other Regulatory Authority or governmental entity, nor, to the Company’s knowledge, is any such claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action threatened; (iii) the Company is not a party to any corporate integrity agreements, monitoring agreements, consent decrees, settlement orders, or similar agreements with or imposed by any Regulatory Authority or other governmental entity; and (iv) neither the Company nor any of its employees, officers or directors has been excluded, suspended or debarred from participation in any U.S. federal health care program or human clinical research or, to the knowledge of the Company, is subject to an inquiry, investigation, proceeding or other similar action by a Regulatory Authority or other governmental entity that could reasonably be expected to result in debarment, suspension, or exclusion.

(cc) All Necessary Permits, etc. The Company and its subsidiaries possess all certificates, authorizations and permits issued by the appropriate federal, state or foreign regulatory authorities necessary to conduct their respective businesses, including, without limitation, from the Regulatory Authorities, and neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any such certificate, authorization or permit which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would have a Material Adverse Change on the Company and its subsidiaries, taken as a whole, except as described in the Registration Statement and Prospectus.

(dd) Compliance with ERISA. Except as would not, singly or in the aggregate, reasonably be expected to have a Material Adverse Change on the Company and its subsidiaries, taken as a whole, (i) each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), that is sponsored, maintained, administered or contributed to by the Company has been maintained in material compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to ERISA and the Internal Revenue Code of 1986, as amended (the “Code”), and (ii) neither the Company nor any member of its “Controlled Group” (defined as any trade or business, whether or not incorporated, that would be regarded as a single employer with the Company under Section 414 of the Code) (x) has ever sponsored, maintained, contributed to or has had any obligation to contribute to, any employee benefit plan that is subject to Title IV of ERISA or any “multiemployer plan” as defined in Section 3(37) of ERISA or (y) has incurred, or reasonably expects to incur, any liability under Title IV of ERISA.

(ee) Preparation of the Financial Statements. The financial statements included or incorporated by reference in each of the Registration Statement and the Prospectus, together with the related notes thereto, comply as to form in all material respects with the applicable accounting requirements of the Securities Act and present fairly the consolidated financial position of the Company and its subsidiaries as of the dates shown and its results of operations and comprehensive loss, statements of convertible preferred units and convertible preferred stock and members’ and stockholders’ deficit and cash flows for the periods shown, and such financial statements have been prepared in conformity with generally accepted accounting principles in the United States

- 15 -

(“U.S. 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. The other financial information included in each of the Registration Statement and the Prospectus has been derived from the accounting records of the Company and its consolidated subsidiaries and presents fairly in all material respects the information shown thereby. The statistical, industry-related and market-related data included in each of the Registration Statement and the Prospectus are based on or derived from sources which the Company reasonably and in good faith believes are reliable and accurate and such data is consistent with the sources from which they are derived, in each case in all material respects. No other financial statements or supporting schedules are required to be included in the Registration Statement or the Prospectus.

(ff) Independent Accountants. Ernst & Young LLP or other accountants who have certified certain financial statements of the Company and its subsidiaries filed with the Commission and included or incorporated by reference in each of the Registration Statement and the Prospectus, is an independent registered public accounting firm with respect to the Company within the meaning of the Securities Act and the applicable rules and regulations thereunder adopted by the Commission and the Public Company Accounting Oversight Board (United States) (the “PCAOB”).

(gg) Company’s Accounting System. The Company and each of its subsidiaries maintain a system of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with U.S. GAAP and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; (iv) 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 (v) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement and the Prospectus fairly presents the information called for in all material respects and is prepared in accordance with the Commission’s rules and guidelines applicable thereto. 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 affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(hh) Tax Law Compliance. 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, singly or in the aggregate, reasonably be expected to have a Material Adverse Change on the Company and its subsidiaries, taken as a whole) and have paid all taxes required to be paid thereon (except for cases in which the failure to file or pay would not, singly or in the aggregate, reasonably be expected to have a Material Adverse Change on the Company and its subsidiaries, taken as a whole, or, except as currently being contested in good faith and for which reserves required by U.S. GAAP have been created in the financial statements of the Company), and no tax deficiency has been determined adversely to the Company or any of its subsidiaries which, singly or in the aggregate, has had (nor does the Company nor any of its subsidiaries have any notice or knowledge of any tax deficiency which could reasonably be expected to be determined adversely to the Company or its subsidiaries and which could reasonably be expected to have) a Material Adverse Change on the Company and its subsidiaries, taken as a whole.

- 16 -

(ii) Emerging Growth Company. Except as described in the Registration Statement and Prospectus, the Company has been and is an “emerging growth company,” as defined in Section 2(a) of the Securities Act.

(jj) XBRL. The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement 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.

(kk) No Price Stabilization or Manipulation. The Company has not taken and will not take, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares.

(ll) Exchange Act Compliance. The documents incorporated or deemed to be incorporated by reference in the Prospectus, 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 Exchange Act, and, when read together with the other information in the Prospectus, at the Settlement Dates, will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(mm) Disclosure Controls. The Company maintains disclosure controls and procedures (as such is defined in Rule 13a-15(e) under the Exchange Act) that comply with the requirements of the Exchange Act; such disclosure controls and procedures have been designed to ensure that information required to be disclosed by the Company in reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the Commission’s rules and forms, including controls and procedures designed to ensure that such information is accumulated and communicated to the Company’s management to allow timely decisions regarding disclosures. The Company has conducted evaluations of the effectiveness of their disclosure controls as required by Rule 13a-15 of the Exchange Act.

(nn) Listing. The Company is subject to and in compliance in all material respects with the reporting requirements of Section 13 or Section 15(d) of the Exchange Act. The Common Stock is registered pursuant to Section 12(b) or Section 12(g) of the Exchange Act and is listed on Nasdaq, and the Company has taken no action designed to, or reasonably likely to have the effect of, terminating the registration of the Common Stock under the Exchange Act or delisting the Common Stock from Nasdaq, nor has the Company received any notification that the Commission or Nasdaq is contemplating terminating such registration or listing. The Company has submitted a Listing of Additional Shares Notification Form with Nasdaq covering all of the Shares; the Company has taken all reasonably necessary actions to ensure that it will be in compliance with all applicable corporate governance requirements set forth in Nasdaq’s listing rules that are then in effect.

- 17 -

(oo) Brokers. Except for Leerink Partners, there is no broker, finder or other party that is entitled to receive from the Company any brokerage or finder’s fee or other fee or commission as a result of any transactions contemplated by this Agreement.

(pp) No Reliance. The Company has not relied upon Leerink Partners or legal counsel for Leerink Partners for any legal, tax or accounting advice in connection with the offering and sale of the Shares.

(qq) Forward-Looking Statement. No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) included in any of the Registration Statement or the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

(rr) Registration Rights. There are no persons (as such term is defined in Rule 1-02 of Regulation S-X promulgated under the Securities Act) with registration or other similar rights to have any equity or debt securities of the Company registered for sale under the Registration Statement or included in the offering contemplated by this Agreement, except for such rights as have been duly waived in a writing previously furnished to Leerink Partners.

(ss) Outbound Investment Security Program. Neither the Company nor any of its subsidiaries is a “covered foreign person”, as that term is defined in 31 C.F.R. § 850.209. Neither the Company nor any of its subsidiaries currently engages, or has plans to engage, directly or indirectly, in a “covered activity”, as that term is defined in 31 C.F.R. § 850.208 (“Covered Activity”). The Company does not have any joint venture that engages in or plans to engage in any Covered Activity. The Company also does not, directly or indirectly, hold a board seat on, have a voting or equity interest in, or have any contractual power to direct or cause the direction of the management or policies of any person or persons that engages or plans to engage in any Covered Activity.

(tt) Other At The Market Sales Agreements. The Company is not a party to any agreement with an agent or underwriter for any other “at the market” offering.

Any certificate signed by an officer of the Company and delivered to Leerink Partners or to counsel for Leerink Partners pursuant to or in connection with this Agreement shall be deemed to be a representation and warranty by the Company to Leerink Partners as to the matters set forth therein.

The Company acknowledges that Leerink Partners and, for purposes of the opinions to be delivered pursuant to Section 7 hereof, counsel to the Company and counsel to Leerink Partners, will rely upon the accuracy and truthfulness of the foregoing representations and hereby consents to such reliance.

- 18 -

7. Covenants of the Company. The Company covenants and agrees with Leerink Partners that:

(a) Registration Statement Amendments. After the date of this Agreement and during any period in which a Prospectus relating to any Shares is required to be delivered by Leerink Partners under the Securities Act (including in circumstances where such requirement may be satisfied pursuant to Rule 172 under the Securities Act), (i) the Company will notify Leerink Partners promptly of the time when any subsequent amendment to the Registration Statement, other than documents incorporated by reference or amendments or supplements that do not name Leerink Partners or do not relate to the transactions contemplated by this Agreement, has been filed with the Commission and/or has become effective or any subsequent supplement to the Prospectus, other than documents incorporated by reference, has been filed and of any request by the Commission for any amendment or supplement to the Registration Statement or Prospectus or for additional information related to the transactions contemplated by this Agreement or for additional information related to the transactions contemplated by this Agreement, (ii) the Company will prepare and file with the Commission, promptly upon Leerink Partners’ reasonable request, any amendments or supplements to the Registration Statement or Prospectus that, in Leerink Partners’ reasonable opinion, may be necessary or advisable in connection with the distribution of the Shares by Leerink Partners (provided, however, that the failure of Leerink Partners to make such request shall not relieve the Company of any obligation or liability hereunder, or affect Leerink Partners’ right to rely on the representations and warranties made by the Company in this Agreement and provided, further, that the only remedy Leerink Partners shall have with respect to the failure by the Company to make such filing (other than Leerink Partners’ rights under Section 9 hereof) shall be to cease making sales under this Agreement until such amendment or supplement is filed); (iii) the Company will not file any amendment or supplement to the Registration Statement or Prospectus, other than documents incorporated by reference, relating to the Shares or a security convertible into the Shares unless a copy thereof has been submitted to Leerink Partners within a reasonable period of time before the filing and Leerink Partners has not reasonably objected thereto (provided, however, that the failure of Leerink Partners to make such objection shall not relieve the Company of any obligation or liability hereunder, or affect Leerink Partners’ right to rely on the representations and warranties made by the Company in this Agreement and provided, further, that the only remedy Leerink Partners shall have with respect to the failure by the Company to obtain such consent (other than Leerink Partners’ rights under Section 9 hereof) shall be to cease making sales under this Agreement until such amendment or supplement is filed) and the Company will furnish to Leerink Partners at the time of filing thereof a copy of any document that upon filing is deemed to be incorporated by reference into the Registration Statement or Prospectus, except for those documents available via EDGAR; (iv) the Company will cause each amendment or supplement to the Prospectus, other than documents incorporated by reference, to be filed with the Commission as required pursuant to the applicable paragraph of Rule 424(b) of the Securities Act, and (v) prior to the termination of this Agreement, the Company will notify Leerink Partners if at any time the Registration Statement shall no longer be effective as a result of the passage of time pursuant to Rule 415 under the Securities Act or otherwise.

- 19 -

(b) Notice of Commission Stop Orders. The Company will advise Leerink Partners, promptly after it receives notice or obtains knowledge thereof, of the issuance or threatened issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement, of the suspension of the qualification of the Shares for offering or sale in any jurisdiction, or of the initiation or threatening of any proceeding for any such purpose; and it will promptly use its commercially reasonable efforts to prevent the issuance of any stop order or to obtain its withdrawal if such a stop order should be issued. The Company will advise Leerink Partners promptly after it receives any request by the Commission for any amendments to the Registration Statement or any amendment or supplements to the Prospectus or for additional information related to the offering of the Shares or for additional information related to the Registration Statement or the Prospectus.

(c) Delivery of Prospectus; Subsequent Changes. During any period in which a Prospectus relating to the Shares is required to be delivered by Leerink Partners under the Securities Act with respect to a pending sale of the Shares, (including in circumstances where such requirement may be satisfied pursuant to Rule 172 under the Securities Act), the Company will use commercially reasonable efforts to comply with all requirements imposed upon it by the Securities Act, as from time to time in force, and to file on or before their respective due dates (taking into account any extensions available under the Exchange Act) all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Sections 13(a), 13(c), 14, 15(d) or any other provision of or under the Exchange Act. If during such period any event occurs as a result of which the Prospectus as then amended or supplemented would include an untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances then existing, not misleading, or if during such period it is necessary to amend or supplement the Registration Statement or Prospectus to comply with the Securities Act, the Company will promptly notify Leerink Partners to suspend the offering of Shares during such period and the Company will promptly amend or supplement the Registration Statement or Prospectus (at the expense of the Company) so as to correct such statement or omission or effect such compliance; provided, however, that the Company may delay the filing of any amendment or supplement, if in the judgment of the Company, it is in the best interest of the Company to do so.

(d) Listing of Shares. During any period in which the Prospectus relating to the Shares is required to be delivered by Leerink Partners under the Securities Act with respect to a pending sale of the Shares (including in circumstances where such requirement may be satisfied pursuant to Rule 172 under the Securities Act), the Company will use its commercially reasonable efforts to cause the Shares to be listed on Nasdaq and to qualify the Shares for sale under the securities laws of such jurisdictions as Leerink Partners reasonably designates and to continue such qualifications in effect so long as required for the distribution of the Shares; provided, however, that the Company shall not be required in connection therewith to qualify as a foreign corporation or dealer in securities or file a general consent to service of process in any jurisdiction.

(e) Delivery of Registration Statement and Prospectus. The Company will furnish to Leerink Partners and its counsel (at the expense of the Company) copies of the Registration Statement, the Prospectus (including all documents incorporated by reference therein) and all amendments and supplements to the Registration Statement or Prospectus that are filed with the Commission during any period in which a Prospectus relating to the Shares is required to be delivered under the Securities Act (including all documents filed with the Commission during such period that are deemed to be incorporated by reference therein), in each case as soon as reasonably practicable and in such quantities as Leerink Partners may from time to time reasonably request

- 20 -

and, at Leerink Partners’ request, will also furnish copies of the Prospectus to each exchange or market on which sales of the Shares may be made; provided, however, that the Company shall not be required to furnish any document (other than the Prospectus) to Leerink Partners to the extent such document is available on EDGAR.

(f) Earnings Statement. The Company will make generally available to its security holders as soon as reasonably practicable, but in any event not later than 15 months after the end of the Company’s current fiscal quarter, an earnings statement covering a 12-month period that satisfies the provisions of Section 11(a) and Rule 158 of the Securities Act, which requirement may be satisfied by publicly filing the required information on EDGAR.

(g) Expenses. The Company, whether or not the transactions contemplated hereunder are consummated or this Agreement is terminated, in accordance with the provisions of Section 11 hereunder, will pay the following expenses all incident to the performance of its obligations hereunder, including, but not limited to, expenses relating to (i) the preparation, printing and filing of the Registration Statement and each amendment and supplement thereto, of each Prospectus and of each amendment and supplement thereto, (ii) the preparation, issuance and delivery of the Shares, (iii) the qualification of the Shares under securities laws in accordance with the provisions of Section 7(d) of this Agreement, including filing fees (provided, however, that any fees or disbursements of counsel for Leerink Partners in connection therewith shall be paid by Leerink Partners except as set forth in (vii) below), (iv) the printing and delivery to Leerink Partners of copies of the Prospectus and any amendments or supplements thereto, and of this Agreement, (v) the fees and expenses incurred in connection with the listing or qualification of the Shares for trading on Nasdaq, (vi) the filing fees and expenses, if any, of the Commission, (vii) the filing fees and associated legal expenses of Leerink Partners’ outside counsel for filings with the FINRA Corporate Financing Department, such legal expense reimbursement not to exceed $10,000, and (viii) the reasonable fees and disbursements of Leerink Partners’ outside counsel in connection with this Agreement, the Registration Statement and the Prospectus; provided that such fees and disbursements shall not exceed (A) $75,000 in connection with the execution of this Agreement and the filing of the Registration Statement and the Company’s delivery of the initial certificate pursuant to Section 7(m), (B) in an amount not to exceed $25,000 in connection with each Bring-Down Date (as defined below) involving the filing of a Form 10-K (including any Form 10-K/A containing amended financial information or a material amendment to the previously filed Form 10-K) on which the Company is required to provide a certificate pursuant to Section 7(m) and (C) in an amount not to exceed $15,000 in connection with each other Bring-Down Date on which the Company is required to provide a certificate pursuant to Section 7(m).

(h) Use of Proceeds. The Company will use the Net Proceeds as described in the Prospectus and any applicable Prospectus Supplement in the section entitled “Use of Proceeds.”

(i) Notice of Other Sales. Without the prior written consent of Leerink Partners, the Company will not, directly or indirectly, offer to sell, sell, contract to sell, grant any option to sell or otherwise dispose of any shares of Common Stock (other than the Shares offered pursuant to this Agreement) or securities convertible into or exchangeable or exercisable for shares of Common Stock, warrants or any rights to purchase or acquire shares of Common Stock during the pendency of any Placement Notice given hereunder, and for five (5) Trading Days following the

- 21 -

termination of any Placement Notice given hereunder; and will not directly or indirectly in any other “at the market offering” or continuous equity transaction offer to sell, sell, contract to sell, grant any option to sell or otherwise dispose of any shares of Common Stock (other than the Shares offered pursuant to this Agreement) or securities convertible into or exchangeable or exercisable for shares of Common Stock, warrants or any rights to purchase or acquire, shares of Common Stock prior to the later of the termination of this Agreement and the fifth day immediately following the final Settlement Date with respect to Shares sold pursuant to such Placement Notice; provided, that such notice shall not be required in connection with the (i) issuance, grant or sale of Common Stock, options to purchase shares of Common Stock, restricted shares of Common Stock, restricted stock units or other equity awards or Common Stock issuable upon the exercise of options or other equity awards pursuant to any stock option, stock bonus or other stock plan or arrangement whether now in effect or hereafter implemented (and the issuance by the Company of shares of Common Stock upon the exercise or vesting thereof), (ii) the issuance of securities in connection with an acquisition, merger or sale or purchase of assets, (iii) the issuance or sale of Common Stock pursuant to any dividend reinvestment plan that the Company may adopt from time to time provided the implementation of such is disclosed to Leerink Partners in advance, (iv) any shares of common stock issuable upon the exchange, conversion or redemption of securities or the exercise of warrants, options or other rights in effect or outstanding or disclosed in filings by the Company available on EDGAR, or (v) the issuance of any shares of Common Stock, or securities convertible into or exercisable for Common Stock, offered and sold in a privately negotiated transaction to licensors, vendors, customers, or strategic partners and otherwise conducted in a manner so as not to be integrated with the offering of the Shares contemplated hereby, provided, however, that in the case of clause (v), any such issuance shall not exceed 5.0% of the aggregate shares of Common Stock of the Company then outstanding. Notwithstanding the foregoing provisions, nothing herein shall be construed to restrict the Company’s ability, or require the Company to provide notice to Leerink Partners, to file a registration statement under the Securities Act in respect of any security of the Company, including Common Stock.

(j) Change of Circumstances. The Company will, at any time during the pendency of a Placement Notice or sale of Shares, advise Leerink Partners promptly after it shall have received notice or obtained knowledge thereof, of any information or fact that would alter or affect in any material respect any opinion, certificate, letter or other document provided to Leerink Partners pursuant to this Agreement.

(k) Due Diligence Cooperation. During the term of this Agreement, the Company will cooperate with any reasonable due diligence review conducted by Leerink Partners or its agents in connection with the transactions contemplated hereby, including, without limitation, providing information and making available documents and senior corporate officers, during regular business hours and at the Company’s principal offices, as Leerink Partners may reasonably request.

(l) Required Filings Relating to Sale of Shares. The Company agrees that on such dates as the Securities Act shall require, the Company will (i) file a prospectus supplement with the Commission under the applicable paragraph of Rule 424(b) under the Securities Act and (ii) deliver such number of copies of each such prospectus supplement to each exchange or market on which such sales were effected as may be required by the rules or regulations of such exchange or market. The Company shall disclose in its quarterly reports on Form 10-Q and in its annual report

- 22 -

on Form 10-K, the number of the Shares sold through Leerink Partners under this Agreement, and the gross proceeds and Net Proceeds to the Company from the sale of the Shares and the compensation paid by the Company with respect to sales of the Shares pursuant to this Agreement during the relevant quarter or, in the case of an Annual Report on Form 10-K, during the fiscal year covered by such Annual Report and the fourth quarter of such fiscal year.

(m) Bring-Down Dates; Certificate. On or prior to the date on which the Company first delivers a Placement Notice pursuant to this agreement (the “First Placement Notice Date”) and each time thereafter during the term of this Agreement (i) the Company files the Prospectus relating to the Shares or amends or supplements the Registration Statement or the Prospectus relating to the Shares (other than a prospectus supplement filed in accordance with Section 7(l) of this Agreement) by means of a post-effective amendment, sticker, or supplement but not by means of incorporation of document(s) by reference to the Registration Statement or the Prospectus relating to the Shares; (ii) the Company files an annual report on Form 10-K under the Exchange Act; (iii) the Company files its quarterly reports on Form 10-Q under the Exchange Act; or (iv) the Company files a current report on Form 8-K containing amended financial information (other than an earnings release or other information “furnished” pursuant to Items 2.02, 7.01 or 9.01 of Form 8-K) under the Exchange Act (each date of filing of one or more of the documents referred to in clauses (i) through (iv) shall be a “Bring-Down Date”); the Company shall furnish Leerink Partners (but in the case of clause (iv) above only if (1) a Placement Notice is pending or in effect and (2) Leerink Partners requests such certificate within two (2) Trading Days after the filing of such Form 8-K with the Commission) with a certificate, in the form attached hereto as Exhibit 7(m). The requirement to provide a certificate under this Section 7(m) shall automatically be waived for any Bring-Down Date occurring at a time at which no Agency Transaction is pending, which waiver shall continue until the earlier to occur of the date the Company delivers a Placement Notice hereunder (which for such calendar quarter shall be considered a Bring-Down Date) and the next occurring Bring-Down Date. Notwithstanding the foregoing, if the Company subsequently decides to sell Shares in an Agency Transaction following a Bring-Down Date when the Company relied on such waiver and did not provide Leerink Partners with a certificate under this Section 7(m), then before the Company delivers the Placement Notice or Leerink Partners sells any Shares pursuant to such Agency Transaction, the Company shall provide Leerink Partners with a certificate, in the form attached hereto as Exhibit 7(m), dated the date of the Placement Notice. Within two (2) Trading Days of each Representation Date, the Company shall have furnished to Leerink Partners such further information, certificates and documents as Leerink Partners may reasonably request.

(n) Legal Opinion. On or prior to the First Placement Notice Date and on any date which the Company is obligated to deliver a certificate pursuant to Section 7(m) for which no waiver is applicable, the Company shall cause to be furnished to Leerink Partners a written opinion of Wilmer Cutler Pickering Hale and Dorr LLP (“Company Counsel”), or other counsel satisfactory to Leerink Partners, in form and substance reasonably satisfactory to Leerink Partners and its counsel, dated the date that the opinion is required to be delivered, modified, as necessary, to relate to the Registration Statement and the Prospectus as then amended or supplemented; provided, however, that in lieu of such opinion for subsequent Bring-Down Dates, counsel may furnish Leerink Partners with a letter to the effect that Leerink Partners may rely on a prior opinion delivered under this Section 7(n) to the same extent as if it were dated the date of such letter (except that statements in such prior opinion shall be deemed to relate to the Registration Statement and the Prospectus as amended or supplemented at such Bring-Down Date).

- 23 -

(o) Intellectual Property Opinion. On or prior to the First Placement Notice Date and on any date which the Company is obligated to deliver a certificate pursuant to Section 7(m) for which no waiver is applicable, the Company shall cause to be furnished to Leerink Partners a written opinion of Proskauer Rose LLP, counsel for the Company with respect to intellectual property matters, or such other intellectual property counsel satisfactory to Leerink Partners (“Intellectual Property Counsel”), in form and substance reasonably satisfactory to Leerink Partners and its counsel, dated the date that the opinion is required to be delivered, modified, as necessary, to relate to the Registration Statement and the Prospectus as then amended or supplemented; provided, however, that in lieu of such opinion for subsequent Bring-Down Dates, Intellectual Property Counsel may furnish Leerink Partners with a letter to the effect that Leerink Partners may rely on a prior opinion delivered under this Section 7(o) to the same extent as if it were dated the date of such letter (except that statements in such prior opinion shall be deemed to relate to the Registration Statement and the Prospectus as amended or supplemented at such Bring-Down Date).

(p) Comfort Letter. On or prior to the First Placement Notice Date and on any date which the Company is obligated to deliver a certificate in the form attached hereto as Exhibit 7(m) for which no waiver is applicable, the Company shall cause its independent accountants to furnish Leerink Partners letters (the “Comfort Letters”), dated the date the Comfort Letter is delivered, in form and substance reasonably satisfactory to Leerink Partners, (i) confirming that they are an independent registered public accounting firm within the meaning of the Securities Act and the PCAOB, (ii) stating, as of such date, the conclusions and findings of such firm with respect to the financial information and other matters ordinarily covered by accountants’ “comfort letters” to Leerink Partners in connection with registered public offerings (the first such letter, the “Initial Comfort Letter”) and (iii) updating the Initial Comfort Letter with any information that would have been included in the Initial Comfort Letter had it been given on such date and modified as necessary to relate to the Registration Statement and the Prospectus, as amended and supplemented to the date of such letter; provided that the Company shall be required to furnish to Leerink Partners no more than one Comfort Letter hereunder per filing of annual report on Form 10-K and quarterly report on Form 10-Q insofar as the Comfort Letter relates to such filings.

(q) Market Activities. The Company will not, directly or indirectly, (i) take any action designed to cause or result in, or that constitutes or might reasonably be expected to constitute, the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Shares or (ii) sell, bid for, or purchase the Common Stock to be issued and sold pursuant to this Agreement in violation of Regulation M, or pay anyone any compensation for soliciting purchases of the Shares other than Leerink Partners; provided, however, that the Company may bid for and purchase shares of its common stock in accordance with Rule 10b-18 under the Exchange Act.

(r) Insurance. The Company and its subsidiaries shall maintain, or cause to be maintained, insurance in such amounts and covering such risks as is reasonable and customary for the business for which it is engaged.

- 24 -

(s) Compliance with Laws. The Company and each of its subsidiaries shall maintain, or cause to be maintained, all material environmental permits, licenses and other authorizations required by federal, state and local law in order to conduct their businesses as described in the Prospectus, and the Company and each of its subsidiaries shall conduct their businesses, or cause their businesses to be conducted, in substantial compliance with such permits, licenses and authorizations and with applicable Environmental Laws, except where the failure to maintain or be in compliance with such permits, licenses and authorizations would not reasonably be expected to result in a Material Adverse Change.

(t) Investment Company Act. The Company will conduct its affairs in such a manner so as to reasonably ensure that neither it nor its subsidiaries will be or become, at any time prior to the termination of this Agreement, an “investment company,” as such term is defined in the Investment Company Act, assuming no change in the Commission’s current interpretation as to entities that are not considered an investment company.

(u) Securities Act and Exchange Act. The Company will use its reasonable best efforts to comply with all requirements imposed upon it by the Securities Act and the Exchange Act as from time to time in force, so far as necessary to permit the continuance of sales of, or dealings in, the Shares as contemplated by the provisions hereof and the Prospectus.

(v) No Offer to Sell. Other than the Prospectus and a Permitted Free Writing Prospectus, neither Leerink Partners nor the Company (including its agents and representatives, other than Leerink Partners in its capacity as such) will make, use, prepare, authorize, approve or refer to any written communication (as defined in Rule 405 under the Securities Act), required to be filed with the Commission, that constitutes an offer to sell or solicitation of an offer to buy Common Stock hereunder.

(w) Sarbanes-Oxley Act. The Company and its subsidiaries will use their best efforts to comply with all effective applicable provisions of the Sarbanes-Oxley Act.

(x) Affirmation. Each Placement Notice delivered by the Company to Leerink Partners shall be deemed to be (i) an affirmation that the representations, warranties and agreements of the Company herein contained and contained in any certificate delivered to Leerink Partners pursuant hereto are true and correct at the time of delivery of such Placement Notice, and (ii) an undertaking that such representations, warranties and agreements will be true and correct on any applicable Time of Sale and Settlement Date, as though made at and as of each such time (it being understood that such representations, warranties and agreements shall relate to the Registration Statement and the Prospectus as amended and supplemented to the time of such Placement Notice acceptance).

(y) Renewal. If, immediately prior to the third anniversary of the initial effective date of the Registration Statement (the “Renewal Date”), any of the Shares remain unsold and this Agreement has not been terminated, the Company will, if it has not already done so and is eligible to do so, prior to the Renewal Date, file a new shelf registration statement or, if applicable, an automatic shelf registration statement relating to the Shares that may be offered and sold pursuant to this Agreement (which shall include a prospectus reflecting the number or amount of Shares that may be offered and sold pursuant to this Agreement), in a form reasonably satisfactory to

- 25 -

Leerink Partners and its counsel, and, if such registration statement is not an automatic shelf registration statement, will use its best efforts to cause such registration statement to be declared effective within 180 days after the Renewal Date. The Company will take all other reasonable actions necessary or appropriate to permit the public offer and sale of the Shares to continue as contemplated in the expired registration statement and this Agreement. From and after the effective date thereof, references herein to the “Registration Statement” shall include such new shelf registration statement or such new automatic shelf registration statement, as the case may be.

(z) General Instruction I.B.6. of Form S-3. If, from and after the date of this Agreement, the Company is no longer eligible to use Form S-3 pursuant to General Instruction I.B.1 but remains eligible to use Form S-3 pursuant to General Instruction I.B.6. at the time it files with the Commission an annual report on Form 10-K or any post-effective amendment to the Registration Statement, then it shall promptly notify Leerink Partners and, within two Business Days (as defined below) after the date of filing of such annual report on Form 10-K or amendment to the Registration Statement, the Company shall file a new prospectus supplement with the Commission reflecting the number of shares of Common Stock available to be offered and sold by the Company under this Agreement pursuant to General Instruction I.B.6. of Form S-3; provided, however, that the Company may delay the filing of any such prospectus supplement for up to 30 days if, in the reasonable judgment of the Company, it is in the best interest of the Company to do so, provided that no Placement Notice is in effect or pending during such time. Until such time as the Company shall have corrected such misstatement or omission or effected such compliance, the Company shall not notify Leerink Partners to resume the offering of Shares.

(aa) Tax Indemnity. The Company will indemnify and hold harmless Leerink Partners against any documentary, stamp or similar issue tax, including any interest and penalties, on the issue and sale of the Shares.

(bb) Transfer Agent. The Company has engaged and will maintain, at its sole expense, a transfer agent and registrar for the Common Stock.

8. Conditions to Leerink Partners’ Obligations. The obligations of Leerink Partners hereunder with respect to a Placement Notice will be subject to the continuing accuracy and completeness of the representations and warranties made by the Company herein, to the due performance by the Company of its obligations hereunder and thereunder, to the completion by Leerink Partners of a due diligence review satisfactory to Leerink Partners in its reasonable judgment, and to the continuing satisfaction (or waiver by Leerink Partners in its sole discretion) of the following additional conditions:

(a) Registration Statement Effective. The Registration Statement shall be effective and shall be available for (i) all sales of Shares issued pursuant to all prior Placement Notices and (ii) the sale of all Shares contemplated to be issued pursuant to any Placement Notice.

(b) No Material Notices. None of the following events shall have occurred and be continuing: (i) receipt by the Company or any of its subsidiaries of any request for additional information from the Commission or any other federal or state governmental authority during the period of effectiveness of the Registration Statement, the response to which would require any

- 26 -

post-effective amendments or supplements to the Registration Statement or the Prospectus; (ii) the issuance by the Commission or any other federal or state governmental authority of any stop order suspending the effectiveness of the Registration Statement or the initiation of any proceedings for that purpose; (iii) receipt by the Company of any notification with respect to the suspension of the qualification or exemption from qualification of any of the Shares for sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; or (iv) the occurrence of any event that makes any material statement made in the Registration Statement or the Prospectus or any material document incorporated or deemed to be incorporated therein by reference untrue in any material respect or that requires the making of any changes in the Registration Statement, related Prospectus or such documents so that, in the case of the Registration Statement, it will not contain any materially untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading and, that in the case of the Prospectus, it will not contain any materially untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(c) No Misstatement or Material Omission. Leerink Partners shall not have advised the Company that the Registration Statement or Prospectus, or any amendment or supplement thereto, contains an untrue statement of fact that in Leerink Partners’ reasonable opinion is material, or omits to state a fact that in Leerink Partners’ reasonable opinion is material and is required to be stated therein or is necessary to make the statements therein not misleading.

(d) Material Changes. Except as contemplated in the Prospectus, or disclosed in the Company’s reports filed with the Commission, there shall not have been any material adverse change, on a consolidated basis, in the authorized capital stock of the Company or any Material Adverse Change or any development that could reasonably be expected to result in a Material Adverse Change, or any downgrading in or withdrawal of the rating assigned to any of the Company’s securities (other than asset backed securities) by any rating organization or a public announcement by any rating organization that it has under surveillance or review its rating of any of the Company’s securities (other than asset backed securities), the effect of which, in the case of any such action by a rating organization described above, in the reasonable judgment of Leerink Partners (without relieving the Company of any obligation or liability it may otherwise have), is so material as to make it impracticable or inadvisable to proceed with the offering of the Shares on the terms and in the manner contemplated in the Prospectus.

(e) Company Counsel Legal Opinion. Leerink Partners shall have received the opinions and negative assurance letters, as applicable, of Company Counsel and Intellectual Property Counsel required to be delivered pursuant to Section 7(n) and Section 7(o), as applicable, on or before the date on which such delivery of such opinions and negative assurance letters are required pursuant to Section 7(n) and Section 7(o), as applicable.

(f) Leerink Partners Counsel Legal Opinion. Leerink Partners shall have received from Cooley LLP, counsel for Leerink Partners, such opinion or opinions, on or before the date on which the delivery of the Company Counsel legal opinion is required pursuant to Section 7(n), with respect to such matters as Leerink Partners may reasonably require, and the Company shall have furnished to such counsel such documents as they reasonably request for enabling them to pass upon such matters.

- 27 -

(g) Comfort Letter. Leerink Partners shall have received the Comfort Letter required to be delivered pursuant to Section 7(p) on or before the date on which such delivery of such Comfort Letter is required pursuant to Section 7(p).

(h) Representation Certificate. Leerink Partners shall have received the certificate required to be delivered pursuant to Section 7(m) on or before the date on which delivery of such certificate is required pursuant to Section 7(m).

(i) Secretary’s Certificate. On or prior to the First Delivery Date, Leerink Partners shall have received a certificate, signed on behalf of the Company by its corporate secretary, in form and substance reasonably satisfactory to Leerink Partners and its counsel.

(j) No Suspension. Trading in the Common Stock shall not have been suspended on Nasdaq.

(k) Other Materials. On each date on which the Company is required to deliver a certificate pursuant to Section 7(m), the Company shall have furnished to Leerink Partners such appropriate further information, certificates and documents as Leerink Partners may have reasonably requested and which are customarily furnished by an issuer of securities in connection with a securities offering. All such opinions, certificates, letters and other documents shall have been in compliance with the provisions hereof. The Company will furnish Leerink Partners with such conformed copies of such opinions, certificates, letters and other documents as Leerink Partners shall have reasonably requested.

(l) Securities Act Filings Made. All filings with the Commission required by Rule 424 with respect to the Shares under the Securities Act to have been filed prior to the issuance of any Placement Notice hereunder shall have been made within the applicable time period prescribed for such filing by Rule 424.

(m) Listing of Additional Shares Notification Form. The Company has submitted a Listing of Additional Shares Notification Form with Nasdaq covering all of the Shares and Nasdaq shall not have raised any objection to the consummation of the transactions contemplated hereby.

(n) No Termination Event. There shall not have occurred any event that would permit Leerink Partners to terminate this Agreement pursuant to Section 11(a).

(o) FINRA. FINRA shall have raised no objection to the terms of the offering contemplated hereby and the amount of compensation allowable or payable to Leerink Partners as described in the Prospectus.

- 28 -

9. Indemnification and Contribution.

(a) Company Indemnification. The Company agrees to indemnify and hold harmless Leerink Partners, the directors, officers, partners, employees and agents of Leerink Partners and each person, if any, who (i) controls Leerink Partners within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, or (ii) is controlled by or is under common control with Leerink Partners from and against any and all losses, claims, liabilities, expenses and damages (including, but not limited to, any and all reasonable investigative, legal and other expenses incurred in connection with, and any and all amounts paid in settlement (in accordance with Section 9(c)) of, any action, suit, investigation or proceeding between any of the indemnified parties and any indemnifying parties or between any indemnified party and any third party (including any governmental or self-regulatory authority), or otherwise, or any claim asserted or threatened), as and when incurred, to which Leerink Partners, or any such person, may become subject under the Securities Act, the Exchange Act or other federal or state statutory law or regulation, at common law or otherwise, insofar as such losses, claims, liabilities, expenses or damages arise out of or are based, directly or indirectly, on (x) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the Prospectus or any amendment or supplement to the Registration Statement or the Prospectus or in any free writing prospectus or in any application or other document executed by or on behalf of the Company or based on written information furnished by or on behalf of the Company filed in any jurisdiction in order to qualify the Common Stock under the securities laws thereof or filed with the Commission, (y) the omission or alleged omission to state in any such document a material fact required to be stated in it or necessary to make the statements therein (solely with respect to the Prospectus, in light of the circumstances under which they were made) not misleading or (z) any breach by any of the indemnifying parties of any of their respective representations, warranties and agreements contained in this Agreement; provided, however, that this indemnity agreement shall not apply to the extent that such loss, claim, liability, expense or damage arises from the sale of the Shares pursuant to this Agreement and is caused directly or indirectly by an untrue statement or omission, or alleged untrue statement or omission, made in reliance upon and in conformity with solely Agent’s Information. As used herein, “Agent’s Information” means, solely, the following information in the Prospectus: the eighth paragraph under the caption “Plan of Distribution” in the Prospectus. This indemnity agreement will be in addition to any liability that the Company might otherwise have.

(b) Leerink Partners Indemnification. Leerink Partners agrees to indemnify and hold harmless the Company and its directors and each officer of the Company that signed the Registration Statement, and each person, if any, who (i) controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act or (ii) is controlled by or is under common control with the Company against any and all loss, liability, claim, damage and expense described in the indemnity contained in Section 9(a), as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendments thereto) or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with the Agent’s Information.

(c) Procedure. Any party that proposes to assert the right to be indemnified under this Section 9 will, promptly after receipt of notice of commencement of any action against such party in respect of which a claim is to be made against an indemnifying party or parties under this Section 9, notify each such indemnifying party in writing of the commencement of such action, enclosing a copy of all papers served, but the omission so to notify such indemnifying party will not relieve the indemnifying party from (i) any liability that it might have to any indemnified party otherwise

- 29 -

than under this Section 9 and (ii) any liability that it may have to any indemnified party under the foregoing provision of this Section 9 unless, and only to the extent that, such omission results in the forfeiture of substantive rights or defenses by the indemnifying party. If any such action is brought against any indemnified party and it notifies the indemnifying party of its commencement, the indemnifying party will be entitled to participate in and, to the extent that it elects by delivering written notice to the indemnified party promptly after receiving notice of the commencement of the action from the indemnified party, jointly with any other indemnifying party similarly notified, to assume the defense of the action, with counsel reasonably satisfactory to the indemnified party, and after notice from the indemnifying party to the indemnified party of its election to assume the defense, the indemnifying party will not be liable to the indemnified party for any legal or other expenses except as provided below and except for the reasonable and documented costs of investigation subsequently incurred by the indemnified party in connection with the defense. The indemnified party will have the right to employ its own counsel in any such action, but the fees, expenses and other charges of such counsel will be at the expense of such indemnified party unless (1) the employment of counsel by the indemnified party has been authorized in writing by the indemnifying party, (2) the indemnified party has reasonably concluded (based on advice of counsel) that there may be legal defenses available to it or other indemnified parties that are different from or in addition to those available to the indemnifying party, (3) a conflict or potential conflict exists (based on advice of counsel to the indemnified party) between the indemnified party and the indemnifying party (in which case the indemnifying party will not have the right to direct the defense of such action on behalf of the indemnified party) or (4) the indemnifying party has not in fact employed counsel reasonably satisfactory to the indemnified party to assume the defense of such action within a reasonable time after receiving notice of the commencement of the action, in each of which cases the reasonable and documented fees, disbursements and other charges of counsel will be at the expense of the indemnifying party or parties. It is understood that the indemnifying party or parties shall not, in connection with any proceeding or related proceedings in the same jurisdiction, be liable for the reasonable fees, disbursements and other charges of more than one separate firm (plus local counsel) admitted to practice in such jurisdiction at any one time for all such indemnified party or parties. All such fees, disbursements and other charges will be reimbursed by the indemnifying party promptly as they are incurred after the indemnifying party receives a written invoice relating to the fees, disbursements and other charges in reasonable detail. An indemnifying party will not, in any event, be liable for any settlement of any action or claim effected without its 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 in any pending or threatened claim, action or proceeding relating to the matters contemplated by this Section 9 (whether or not any indemnified party is a party thereto), unless such settlement, compromise or consent includes an unconditional release of each indemnified party, in form and substance reasonably satisfactory to such indemnified party, from all liability arising or that may arise out of such claim, action or proceeding and 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.

- 30 -

(d) Settlement Without Consent if Failure to Reimburse. If an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for reasonable fees and expenses of counsel for which it is entitled to be reimbursed under this Section 9, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 9(a) effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement.

(e) Contribution. In order to provide for just and equitable contribution in circumstances in which the indemnification provided for in the foregoing paragraphs of this Section 9 is applicable in accordance with its terms but for any reason is held to be unavailable from the Company or Leerink Partners, the Company and Leerink Partners will contribute to the total losses, claims, liabilities, expenses and damages (including any investigative, legal and other expenses reasonably incurred in connection with, and any amount paid in settlement of, any action, suit or proceeding or any claim asserted, but after deducting any contribution received by the Company from persons other than Leerink Partners, such as persons who control the Company within the meaning of the Securities Act, officers of the Company who signed the Registration Statement and directors of the Company, who also may be liable for contribution) to which the Company and Leerink Partners may be subject in such proportion as shall be appropriate to reflect the relative benefits received by the Company on the one hand and Leerink Partners on the other. The relative benefits received by the Company on the one hand and Leerink Partners on the other hand shall be deemed to be in the same proportion as the total Net Proceeds from the sale of the Shares (before deducting expenses) received by the Company bear to the total compensation received by Leerink Partners from the sale of Shares on behalf of the Company. If, but only if, the allocation provided by the foregoing sentence is not permitted by applicable law, the allocation of contribution shall be made in such proportion as is appropriate to reflect not only the relative benefits referred to in the foregoing sentence but also the relative fault of the Company, on the one hand, and Leerink Partners, on the other, with respect to the statements or omission that resulted in such loss, claim, liability, expense or damage, or action, suit, investigation or proceeding in respect thereof, as well as any other relevant equitable considerations with respect to such offering. Such relative fault shall be determined by reference to, among other things, whether the 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 Leerink Partners, the intent of the parties and their relative knowledge, access to information and opportunity to correct or prevent such statement or omission. The Company and Leerink Partners agree that it would not be just and equitable if contributions pursuant to this Section 9(e) were to be determined by pro rata allocation or by any other method of allocation that does not take into account the equitable considerations referred to herein. The amount paid or payable by an indemnified party as a result of the loss, claim, liability, expense, or damage, or action, suit, investigation or proceeding in respect thereof, referred to above in this Section 9(e) shall be deemed to include, for the purpose of this Section 9(e), any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action, suit, investigation or proceeding or claim to the extent consistent with Section 9(c) hereof. Notwithstanding the foregoing provisions of this Section 9(e), Leerink Partners shall not be required to contribute any amount in excess of the commissions received by it under this Agreement and no person found guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) will be entitled to contribution from any

- 31 -

person who was not guilty of such fraudulent misrepresentation. For purposes of this Section 9(e), any person who controls a party to this Agreement within the meaning of Section 15 of the Securities Act, or Section 20 of the Exchange Act, any affiliates of Leerink Partners, any partners, members, officers, directors, employees or agents of Leerink Partners and each person that is controlled by or under common control with Leerink Partners, will have the same rights to contribution as that party, and each officer of the Company who signed the Registration Statement and the directors of the Company will 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 9(e), will notify any such party or parties from whom contribution may be sought, but the omission to so notify 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 9(e) except to the extent that the failure to so notify such other party materially prejudiced the substantive rights or defenses of the party from whom contribution is sought. Except for a settlement entered into pursuant to the last sentence of Section 9(c) hereof or pursuant to this Section 9(e), no party will be liable for contribution with respect to any action or claim settled without its written consent if such consent is required pursuant to Section 9(c) hereof.

10. Representations and Agreements to Survive Delivery. The indemnity and contribution agreements contained in Section 9 of this Agreement and all representations and warranties of the Company herein or in certificates delivered pursuant hereto shall survive, as of their respective dates, regardless of (i) any investigation made by or on behalf of Leerink Partners, any controlling persons, or the Company (or any of their respective officers, directors or controlling persons), (ii) delivery and acceptance of the Shares and payment therefor or (iii) any termination of this Agreement.

11. Termination.

(a) Leerink Partners shall have the right by giving notice as hereinafter specified at any time to terminate this Agreement if (i) any Material Adverse Change, or any development that could reasonably be expected to result in a Material Adverse Change has occurred that, in the reasonable judgment of Leerink Partners, may materially impair the ability of Leerink Partners to sell the Shares hereunder, (ii) the Company shall have failed, refused or been unable to perform any agreement on its part to be performed hereunder; provided, however, in the case of any failure of the Company to deliver (or cause another person to deliver) any certification, opinion, or letter required under Sections 7(m), 7(n), 7(o) or 7(p), Leerink Partners’ right to terminate shall not arise unless such failure to deliver (or cause to be delivered) continues for more than thirty (30) days from the date such delivery was required, or (iii) any other condition of Leerink Partners’ obligations hereunder is not fulfilled, or (iv) any suspension or limitation of trading in the Shares or in securities generally on Nasdaq shall have occurred. Any such termination shall be without liability of any party to any other party except that the provisions of Section 7(g) (Expenses), Section 9 (Indemnification and Contribution), Section 10 (Representations and Agreements to Survive Delivery), Section 16 (Applicable Law; Consent to Jurisdiction) and Section 17 (Waiver of Jury Trial) hereof shall remain in full force and effect notwithstanding such termination. If Leerink Partners elects to terminate this Agreement as provided in this Section 11(a), Leerink Partners shall provide the required notice as specified in Section 12 (Notices).

- 32 -

(b) The Company shall have the right, by giving ten (10) days’ notice as hereinafter specified to terminate this Agreement in its sole discretion at any time after the date of this Agreement. Any such termination shall be without liability of any party to any other party except that the provisions of Section 7(g), Section 9, Section 10, Section 16 and Section 17 hereof shall remain in full force and effect notwithstanding such termination.

(c) Leerink Partners shall have the right, by giving ten (10) days’ notice as hereinafter specified to terminate this Agreement in its sole discretion at any time after the date of this Agreement. Any such termination shall be without liability of any party to any other party except that the provisions of Section 7(g), Section 9, Section 10, Section 16 and Section 17 hereof shall remain in full force and effect notwithstanding such termination.

(d) Unless earlier terminated pursuant to this Section 11, this Agreement shall automatically terminate upon the issuance and sale of all of the Shares through Leerink Partners on the terms and subject to the conditions set forth herein; provided that the provisions of Section 7(g), Section 9, Section 10, Section 16 and Section 17 hereof shall remain in full force and effect notwithstanding such termination.

(e) This Agreement shall remain in full force and effect unless terminated pursuant to Sections 11(a), (b), (c) or (d) above or otherwise by mutual agreement of the parties; provided, however, that any such termination by mutual agreement shall in all cases be deemed to provide that Section 7(g), Section 9, Section 10, Section 16 and Section 17 shall remain in full force and effect. Upon termination of this Agreement, the Company shall not have any liability to Leerink Partners for any discount, commission, or other compensation with respect to any Shares not otherwise sold by Leerink Partners under this Agreement, or otherwise, except with respect to reimbursement of expenses pursuant to Section 7(g).

(f) Any termination of this Agreement shall be effective on the date specified in such notice of termination; provided, however, that such termination shall not be effective until the close of business on the date of receipt of such notice by Leerink Partners or the Company, as the case may be. If such termination shall occur prior to the Settlement Date for any sale of Shares, such Shares shall settle in accordance with the provisions of this Agreement.

12. Notices. All notices or other communications required or permitted to be given by any party to any other party pursuant to the terms of this Agreement shall be in writing, unless otherwise specified in this Agreement, and if sent to Leerink Partners, shall be delivered to

Leerink Partners LLC

1301 Avenue of the Americas, 5th Floor

New York, New York 10019

Attention: Peter M. Fry

E-mail: peter.fry@leerink.com

- 33 -

with a copy (which shall not constitute notice) to:

Leerink Partners LLC

1301 Avenue of the Americas, 5th Floor

New York, New York 10019

Attention: Legal Department

E-mail: LegalNotice@leerink.com

Cooley LLP

55 Hudson Yards

New York, NY 10001

Attention: Daniel I. Goldberg

E-mail: dgoldberg@cooley.com

and if sent to the Company, shall be delivered to:

Xilio Therapeutics, Inc.

828 Winter Street, Suite 300

Waltham, MA 02451

Attention: Chief Legal Officer

with a copy (which shall not constitute notice) to:

Wilmer Cutler Pickering Hale and Dorr LLP

Attention: Cynthia T. Mazareas

email: cynthia.mazareas@wilmerhale.com

Each party to this Agreement may change such address for notices by sending to the parties to this Agreement written notice of a new address for such purpose. Each such notice or other communication shall be deemed given (i) when delivered personally or by verifiable facsimile transmission (with an original to follow) on or before 4:30 p.m., New York City time, on a Business Day, or, if such day is not a Business Day on the next succeeding Business Day, (ii) on the next Business Day after timely delivery to a nationally-recognized overnight courier, (iii) on the Business Day actually received if deposited in the U.S. mail (certified or registered mail, return receipt requested, postage prepaid) and (iv) when delivered by electronic communication, at the time the party sending such electronic communication receives verification of receipt by the receiving party, other than via auto reply. For purposes of this Agreement, “Business Day” shall mean any day on which Nasdaq and commercial banks in the City of New York are open for business. An electronic communication (“Electronic Notice”) shall be deemed written notice for purposes of this Section 12 if sent to the electronic mail address specified by the receiving party in Section 12. Electronic Notice shall be deemed received at the time the party sending Electronic Notice receives actual acknowledgment of receipt from the person whom the notice is sent, other than via auto-reply. Any party receiving Electronic Notice may request and shall be entitled to receive the notice on paper, in a nonelectronic form (“Nonelectronic Notice”), which shall be sent to the requesting party within 10 days of receipt of the written request for Nonelectronic Notice.

- 34 -

13. Successors and Assigns. This Agreement shall inure to the benefit of and be binding upon the Company and Leerink Partners and their respective successors and the affiliates, controlling persons, officers and directors referred to in Section 9 hereof. References to any of the parties contained in this Agreement shall be deemed to include the successors and permitted assigns of such party. Nothing in this Agreement, express or implied, is intended to confer upon any party other than the parties hereto or their respective successors and permitted assigns any rights, remedies, obligations or liabilities under or by reason of this Agreement, except as expressly provided in this Agreement. Neither party may assign its rights or obligations under this Agreement without the prior written consent of the other party; provided, however, that Leerink Partners may assign its rights and obligations hereunder to an affiliate of Leerink Partners without obtaining the Company’s consent, so long as such affiliate is a broker-dealer that is registered with the U.S. Securities and Exchange Commission.

14. Adjustments for Share Splits. The parties acknowledge and agree that all share-related numbers contained in this Agreement shall be adjusted to take into account any share split, share dividend or similar event effected with respect to the Common Stock.

15. Entire Agreement; Amendment; Severability. This Agreement (including all schedules and exhibits attached hereto and Placement Notices issued pursuant hereto) constitutes the entire agreement and supersedes all other prior and contemporaneous agreements and undertakings, both written and oral, among the parties hereto with regard to the subject matter hereof. Neither this Agreement, nor any term hereof, may be amended except pursuant to a written instrument executed by the Company and Leerink Partners; provided, that each party hereto may amend the list of individuals appearing under such party’s name on Schedule 2 by giving notice to the other party hereto. In the event that any one or more of the provisions contained herein, or the application thereof in any circumstance, is held invalid, illegal or unenforceable as written by a court of competent jurisdiction, then such provision shall be given full force and effect to the fullest possible extent that it is valid, legal and enforceable, and the remainder of the terms and provisions herein shall be construed as if such invalid, illegal or unenforceable term or provision was not contained herein, but only to the extent that giving effect to such provision and the remainder of the terms and provisions hereof shall be in accordance with the intent of the parties as reflected in this Agreement. No implied waiver by a party shall arise in the absence of a waiver in writing signed by such party. No failure or delay in exercising any right, power, or privilege hereunder shall operate as a waiver thereof, nor shall any single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any right, power, or privilege hereunder.

16. Applicable Law; Consent to Jurisdiction. This Agreement shall be governed by, and construed in accordance with, the internal laws of the State of New York without regard to the principles of conflicts of laws. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the City of New York, borough of Manhattan, for the adjudication of any dispute hereunder or in connection with any transaction contemplated hereby, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is brought in an inconvenient forum or that the venue of such suit, action or proceeding is improper. Each party hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by mailing a copy thereof (certified or registered mail, return receipt requested) to such party at the address in effect for notices to it under this Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law.

- 35 -

17. Waiver of Jury Trial. The Company and Leerink Partners each hereby irrevocably waives any right it may have to a trial by jury in respect of any claim based upon or arising out of this Agreement or any transaction contemplated hereby.

18. Absence of Fiduciary Relationship. The Company acknowledges and agrees that:

(a) Leerink Partners has been retained solely to act as an arm’s length contractual counterparty to the Company in connection with the sale of the Shares contemplated hereby and that no fiduciary, advisory or agency relationship between the Company and Leerink Partners has been created in respect of any of the transactions contemplated by this Agreement, irrespective of whether Leerink Partners has advised or is advising the Company on other matters;

(b) the Company is capable of evaluating and understanding and understands and accepts the terms, risks and conditions of the transactions contemplated by this Agreement;

(c) the Company has been advised that Leerink Partners and its affiliates are engaged in a broad range of transactions which may involve interests that differ from those of the Company and that Leerink Partners has no obligation to disclose such interests and transactions to the Company by virtue of any fiduciary, advisory or agency relationship; and

(d) the Company waives, to the fullest extent permitted by law, any claims it may have against Leerink Partners, for breach of fiduciary duty or alleged breach of fiduciary duty and agrees that Leerink Partners shall have no liability (whether direct or indirect) to the Company in respect of such a fiduciary claim or to any person asserting a fiduciary duty claim on behalf of or in right of the Company, including stockholders, partners, employees or creditors of the Company.

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

In the event that Leerink Partners is a Covered Entity and Leerink Partners or a BHC Act Affiliate of Leerink Partners becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights under this Agreement that may be exercised against Leerink Partners 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.

- 36 -

For purposes of this Agreement, (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); (B) “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); (C) “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; and (D) “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.

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

[Remainder of Page Intentionally Blank]

- 37 -

If the foregoing correctly sets forth the understanding between the Company and Leerink Partners, please so indicate in the space provided below for that purpose, whereupon this letter shall constitute a binding agreement between the Company and Leerink Partners.

Signature page to Sales Agreement

SCHEDULE 1

FORM OF PLACEMENT NOTICE

Gentlemen:

Pursuant to the terms and subject to the conditions contained in the Sales Agreement between Xilio Therapeutics, Inc. (the “Company”), and Leerink Partners LLC (“Leerink Partners”) dated March 11, 2025, I hereby request on behalf of the Company that Leerink Partners sell up to [[  ] shares]/[$[____] in the aggregate of shares] of the Company’s common stock, par value $0.0001 per share, at a minimum market price of $_______ per share. Sales should begin on the date of this Notice and shall continue until [DATE] [all shares are sold].

SCHEDULE 2

Notice Parties

Company

Leerink Partners

Dan Dubin

[***]

SCHEDULE 3

Compensation

Leerink Partners shall be paid compensation of 3.0% of the gross proceeds from the sales of Shares in an Agency Transaction pursuant to the terms of this Agreement of which this Schedule 3 forms a part.

Exhibit 7(m)

OFFICER CERTIFICATE

Each of [•], the duly qualified and elected Chief Executive Officer of Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), and [•], the duly qualified and elected Chief Financial Officer of the Company, does hereby certify in her or his respective capacity and on behalf of the Company, pursuant to Section 7(m) of the Sales Agreement, dated March 11, 2025 (the “Sales Agreement”), by and between the Company and Leerink Partners LLC, that, after due inquiry, to the best of the knowledge of the undersigned:

(i) The representations and warranties of the Company in Section 6 of the Sales Agreement (A) to the extent such representations and warranties are subject to qualifications and exceptions contained therein relating to materiality or Material Adverse Change, are true and correct on and as of the date hereof with the same force and effect as if expressly made on and as of the date hereof, and (B) to the extent such representations and warranties are not subject to any qualifications or exceptions relating to materiality or Material Adverse Change, are true and correct in all material respects as of the date hereof as if made on and as of the date hereof with the same force and effect as if expressly made on and as of the date hereof.

(ii) The Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied pursuant to the Sales Agreement at or prior to the date hereof.

(iii) As of the date hereof, (A) the Registration Statement complies in all material respects with the requirements of the Securities Act and does not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading, (B) the Prospectus complies in all material respects with the requirements of the Securities Act does not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading and (C) no event has occurred as a result of which it is necessary to amend or supplement the Registration Statement or the Prospectus in order to make the statements therein not untrue or misleading or for clauses (A) and (B) above, to be true and correct.

(iv) There has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change, in the condition (financial or otherwise), earnings, results of operations, business, properties, operations, assets, liabilities or prospects of the Company and its subsidiaries, taken as a whole, whether or not arising from transactions in the ordinary course of business, since the date as of which information is given in the Prospectus, as amended or supplemented to the date hereof.

(v) The Company does not possess any material non-public information.

(vi) The maximum amount of Shares that may be sold pursuant to the Sales Agreement has been duly authorized by the Company’s board of directors or a duly authorized committee thereof pursuant to a resolution or unanimous written consent in accordance with the Company’s certificate of incorporation and bylaws and applicable law.

Cooley LLP and Wilmer Cutler Pickering Hale and Dorr LLP are entitled to rely upon this Certificate in connection with the opinions given by such firms pursuant to the Sales Agreement.

Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Sales Agreement.

Date:          

Exhibit 5.1

Xilio Therapeutics, Inc.

828 Winter Street, Suite 300

Waltham, Massachusetts 02451

Ladies and Gentlemen:

This opinion is furnished to you in connection with (i) the Registration Statement on Form S-3 (File No. 333-268264) (the “Registration Statement”) filed by Xilio Therapeutics, Inc., a Delaware corporation (the “Company”), with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), for the registration of, among other things, shares of common stock, par value $0.0001 per share (“Common Stock”) of the Company, all of which may be issued and sold from time to time on a delayed or continuous basis by the Company pursuant to Rule 415 under the Securities Act at an aggregate initial offering price not to exceed $250,000,000, as set forth in the Registration Statement and the base prospectus contained therein (the “Base Prospectus”) and (ii) the prospectus supplement, dated March 11, 2025 (the “Prospectus Supplement” and, together with the Base Prospectus, the “Prospectus”), relating to the issuance and sale from time to time by the Company of shares of Common Stock having an aggregate offering price of up to $50,000,000 (the “Shares”). The Shares are to be issued and sold pursuant to a Sales Agreement, dated March 11, 2025, by and between the Company and Leerink Partners LLC (the “Sales Agreement”). We are acting as counsel for the Company in connection with the issue and sale by the Company of the Shares.

We have examined and relied upon copies of the Registration Statement and the Prospectus, as filed with the Commission, including the exhibits thereto. We have also examined and relied upon the Sales Agreement, the Restated Certificate of Incorporation of the Company (as amended or restated from time to time, the “Certificate of Incorporation”), the Second Amended and Restated By-Laws of the Company and minutes of meetings of the stockholders and the Board of Directors of the Company including duly authorized committees thereof as provided to us by the Company.

In our examination of the foregoing documents, we have assumed the genuineness of all signatures, the legal capacity of all signatories, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as copies, the authenticity of such original documents and the completeness and accuracy of the corporate minute books of the Company.

We have relied as to certain matters on information obtained from public officials and officers of the Company, and we have assumed (i) all Shares will be issued and sold in compliance with applicable federal and state securities laws and in the manner stated in the Registration Statement, the Prospectus and any applicable prospectus supplement; (ii) there will be sufficient shares of Common Stock authorized under the Certificate of Incorporation and not otherwise reserved for issuance; and (iii) at the time of the issuance and sale of the Shares, the Company will be validly existing as a corporation and in good standing under the laws of the State of Delaware.

We are expressing no opinion herein as to the application of any federal or state law or regulation to the power, authority or competence of any party to any agreement with respect to the Common Stock other than the Company. We have assumed that such agreements are, or will be, the valid and binding obligations of each party thereto other than the Company, and enforceable against each such other party in accordance with their respective terms.

We have assumed for purposes of our opinion below that no authorization, approval, consent or other action by, and no notice to or filing with, any governmental authority or regulatory body or any other third party is required for the due execution, delivery or performance by the Company of any such agreement, or, if any such authorization, approval, consent, action, notice or filing is required, it will have been duly obtained, taken, given or made and will be in full force and effect. We have also assumed that there will not have occurred, prior to the date of issuance of any Common Stock, any change in law affecting the validity or enforceability of such Common Stock and that at the time of the issuance and sale of such Common Stock, the

Board of Directors of the Company (or any committee of the Board of Directors pursuant to authority properly delegated to such committee by the Board of Directors of the Company) shall not have taken any action to rescind or otherwise reduce its prior authorization of the issuance of such Common Stock.

We also express no opinion herein as to the laws of any state or jurisdiction other than the General Corporation Law of the State of Delaware. We also express no opinion herein with respect to compliance by the Company with the securities or “blue sky” laws of any state or other jurisdiction of the United States or of any foreign jurisdiction. We also express no opinion and make no statement herein with respect to the antifraud laws of any jurisdiction.

Based upon and subject to the foregoing, we are of the opinion that the Shares have been duly authorized for issuance and, when the Shares have been issued and paid for in accordance with the terms and conditions of the Sales Agreement, the Shares will be validly issued, fully paid and non-assessable.

Please note that we are opining only as to the matters expressly set forth herein, and no opinion should be inferred as to any other matters. This opinion is based upon currently existing statutes, rules, regulations and judicial decisions, and we disclaim any obligation to advise you of any change in any of these sources of law or subsequent legal or factual developments which might affect any matters or opinions set forth herein.

We hereby consent to the filing of this opinion with the Commission in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act as an exhibit to the Current Report on Form 8-K to be filed by the Company on the date hereof in connection with the issuance and sale of the Shares and to the use of our name therein and in the related Prospectus Supplement under the caption “Legal Matters.” In giving such consent, we do not hereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission.