Underwriting Agreement, dated September 20, 2022, by and among Alpine Immune Sciences, Inc. and Morgan Stanley & Co. LLC, SVB Securities LLC and Cowen and Company, LLC, as representatives of the several underwriters named therein

Alpine Immune Sciences, Inc., a Delaware corporation (the “Company”), proposes to issue and sell to the several underwriters named in Schedule I hereto (the “Underwriters”) 13,606,000 shares of common stock, par value $0.001 per share (the “Common Stock”) of the Company (the “Firm Shares”). The Company also proposes to issue and sell to the several Underwriters not more than an additional 2,040,900 shares of Common Stock (the “Additional Shares”) if and to the extent that Morgan Stanley & Co. LLC, SVB Securities LLC and Cowen and Company LLC, as representatives of the Underwriters (in such capacity, the “Representatives”), shall have determined to exercise, on behalf of the Underwriters, the right to purchase such shares of common stock granted to the Underwriters in Section 2 hereof. The Firm Shares and the Additional Shares are hereinafter collectively referred to as the “Securities.”

The Company has filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (File No. 333- 256107), including a base prospectus dated May 20, 2022, registering the offering and sale of certain securities, including the Securities. The registration statement, as amended at the time it became effective, including the information (if any) deemed to be part of the registration statement at the time of effectiveness pursuant to Rule 430A or Rule 430B under the Securities Act of 1933, as amended (the “Securities Act”), is hereinafter referred to as the “Registration Statement”; the prospectus supplement in the form first used to confirm sales of the Securities (or in the form first made available to the Underwriters by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act) is hereinafter referred to as the “Prospectus Supplement.” The term “Base Prospectus,” means the prospectus dated May 20, 2021, relating to the Securities, in the form in which it has been filed with the Commission as part of the Registration Statement

on or prior to the date of this Agreement. The term “Prospectus” means the Base Prospectus as supplemented by the Prospectus Supplement, and the term “preliminary prospectus” means any preliminary form of the Prospectus. If the Company has filed an abbreviated registration statement to register additional shares of Common Stock pursuant to Rule 462(b) under the Securities Act (a “Rule 462 Registration Statement”), then any reference herein to the term “Registration Statement” shall be deemed to include such Rule 462 Registration Statement.

For purposes of this underwriting agreement (“Agreement”), “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, “Time of Sale Prospectus” means the preliminary prospectus together with the documents and pricing information set forth in Schedule II hereto, and “broadly available road show” means a “bona fide electronic road show” as defined in Rule 433(h)(5) under the Securities Act that has been made available without restriction to any person. As used herein, the terms “Registration Statement,” “preliminary prospectus,” “Time of Sale Prospectus” and “Prospectus” shall include the documents, if any, incorporated by reference therein as of the date hereof. The terms “supplement,” “amendment” and “amend” as used herein with respect to the Registration Statement, the Time of Sale Prospectus, any preliminary prospectus or the Prospectus shall include all documents subsequently filed by the Company with the Commission pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that are deemed to be incorporated by reference therein.

1.Representations and Warranties. The Company represents and warrants to, and agrees with, each of the Underwriters that:

(a)The Registration Statement has become effective; no stop order suspending the effectiveness of the Registration Statement is in effect, and no proceedings for such purpose or pursuant to Section 8A under the Securities Act are pending before or, to the knowledge of the Company, threatened by the Commission.

(b)(i) Each document, if any, filed or to be filed pursuant to the Exchange Act and incorporated by reference in the Time of Sale Prospectus or the Prospectus complied or will comply when so filed in all material respects with the Exchange Act and the applicable rules and regulations of the Commission thereunder, (ii) the Registration Statement, when it became effective, did not contain and, as amended or supplemented, if applicable, 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, (iii) the Registration Statement and the Prospectus comply and, as amended or supplemented, if applicable will comply in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder, (iv) the Time of Sale Prospectus does not, and at the time of each sale of the Securities in connection with the offering when the Prospectus is not yet available to prospective purchasers and at the Closing Date (as defined in Section 4), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any 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 under which they were made, not misleading, (v) each

broadly available road show, if any, when considered together with the Time of Sale Prospectus, does not contain any 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 under which they were made, not misleading and (vi) the Prospectus does not contain and, as amended or supplemented, if applicable will not contain any 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 under which they were made, not misleading, except that the representations and warranties set forth in this paragraph do not apply to statements or omissions in the Registration Statement, the Time of Sale Prospectus or the Prospectus based upon information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use therein.

(c)The Company is not an “ineligible issuer” in connection with the offering pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of the Securities Act and the applicable rules and regulations of the Commission thereunder. Except for the free writing prospectuses, if any, identified in Schedule II hereto, and electronic road shows, if any, each furnished to the Representatives before first use, the Company has not prepared, used or referred to, and will not, without prior consent of the Representatives, prepare, use or refer to, any free writing prospectus.

(d)The Company and each of its subsidiaries have been duly organized, are validly existing as corporations or limited liability entities and are in good standing under the laws of their respective jurisdictions of organization, except where the failure to be so duly organized, validly existing and in good standing would not reasonably be expected to have a Material Adverse Effect (as defined below). The Company and each of its subsidiaries are, and will be, duly licensed or qualified as a foreign corporation for the transaction of business and in good standing under the laws of each other jurisdiction in which their respective ownership or lease of property or the conduct of their respective businesses requires such license or qualification, and have all corporate power and authority necessary to own or hold their respective properties and to conduct their respective businesses as described in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, except where the failure to be so qualified or in good standing or have such power or authority would not, individually or in the aggregate, have a Material Adverse Effect or would reasonably be expected to have a Material Adverse Effect on or affecting the assets, business, operations, earnings, properties, condition (financial or otherwise), prospects, stockholders’ equity or results of operations of the Company and its subsidiaries taken as a whole, or prevent or materially interfere with the consummation of the transactions contemplated hereby (a “Material Adverse Effect”); provided, however, that any of the following, either alone or in combination, shall not be deemed a Material Adverse Effect: (i) effects caused by changes or

circumstances affecting general market conditions in the U.S. economy or which are generally applicable to the industry in which the Company operates, provided that such effects are not borne disproportionately by the Company, (ii) effects resulting from or relating to the announcement or disclosure of the sale of the Securities or other transactions contemplated by this Agreement or (iii) effects caused by any event, occurrence or condition resulting from or relating to the taking of any action in accordance with this Agreement.

(e)The Company has all requisite corporate power and authority to execute, deliver and perform its obligations hereunder. This Agreement has been duly and validly 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.

(f)The Securities to be purchased by the Underwriters from the Company have been duly authorized for issuance and sale to the Underwriters pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein, will be validly issued and fully paid and non-assessable. The Common Stock conforms in all material respects to all statements relating thereto contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus and such description conforms in all material respects to the rights set forth in the instruments defining the same.

(g)The Company has an authorized capitalization as set forth in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus, and all of the issued shares of the Company have been duly authorized and validly issued, are fully paid and non-assessable, conform in all material respects to the description thereof contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus and were not issued in violation of any preemptive right, resale right, right of first refusal or similar right. All of the Company’s options, warrants and other rights to purchase or exchange any securities for shares of the Company’s capital stock have been duly authorized and validly issued, and conform in all material respects to the description thereof contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus. All of the issued shares of capital stock or other ownership interests of each subsidiary of the Company have been duly authorized and validly 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, except for such liens, encumbrances, equities or claims as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. No Person is entitled to preemptive rights, rights of first refusal, rights of participation or similar rights with respect to any securities of the Company, including with respect to the issuance of the Securities contemplated hereby. Except as set forth in the Registration Statement, the Time of Sale Prospectus and the Prospectus, there are no voting agreements, registration rights agreements or other agreements of any kind between the Company and any other Person relating to the securities of the Company,

including the Securities. “Person” means an individual, corporation, partnership, limited liability company, trust, business trust, association, joint stock company, joint venture, sole proprietorship, unincorporated organization, governmental authority or any other form of entity not specifically listed herein.

(h)The execution and delivery by the Company of, and the performance by the Company of its obligations under, this Agreement will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, impose any lien, charge or encumbrance upon any property or assets of the Company and its subsidiaries, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement, license, lease or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject; (ii) result in any violation of the provisions of the certificate of incorporation, charter or bylaws (or similar organizational documents) of the Company or any of its subsidiaries; or (iii) result in any violation of any statute or any judgment, order, decree, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties or assets, except, with respect to clauses (i) and (iii), for such conflicts, breaches, violations, liens, charges, encumbrances or defaults that would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(i)There has not occurred any material adverse change, or any development involving a prospective material adverse change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus.

(j)There are no legal or governmental proceedings pending to which the Company or any of its subsidiaries is a party or of which any property or assets of the Company or any of its subsidiaries is the subject that, if determined adversely to the Company, would, in the aggregate, reasonably be expected to have a Material Adverse Effect or would, in the aggregate, reasonably be expected to have a Material Adverse Effect on the performance of this Agreement or the consummation of the transactions contemplated hereby (i) other than proceedings accurately described in all material respects in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus and proceedings that would not, singly or in the aggregate, have a Material Adverse Effect on the Company and its subsidiaries, taken as a whole, or on the power or ability of the Company to perform its obligations under this Agreement or to consummate the transactions contemplated by each of the Registration Statement, the Time of Sale Prospectus and the Prospectus or (ii) that are required to be described in the Registration Statement, the Time of Sale Prospectus or the Prospectus and are not so described. To the Company’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or others.

(k)There are no contracts or other documents required to be described in the Registration Statement, the Time of Sale Prospectus or the Prospectus or filed as exhibits to the Registration Statement pursuant to Item 601 of Regulation S-K under the Securities

Act (“Regulation S-K”) that are not described and filed as required. The statements made in the Registration Statement, the Time of Sale Prospectus and the Prospectus, insofar as they purport to constitute summaries of the terms of the contracts and other documents described and filed pursuant to Item 601 of Regulation S-K, constitute accurate summaries of the terms of such contracts and documents in all material respects.

(l)Each preliminary prospectus relating to the Securities to be sold hereunder and filed as part of the Registration Statement as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act and the applicable rules and regulations of the Commission thereunder.

(m)The Company is not, and after giving effect to the offer and sale of the Securities and the application of the proceeds therefrom as described in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus will not be, (i) required to register as an “investment company” (within the meaning of the Investment Company Act of 1940, as amended (the “Investment Company Act”)) or (ii) a “business development company” (as defined in Section 2(a)(48) of the Investment Company Act).

(n)The Company and each of its subsidiaries maintains 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 conducts their businesses in substantial compliance with such permits, licenses and authorizations and 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”), except where the failure to maintain or be in compliance with such permits, licenses and authorizations would not reasonably be expected to have a Material Adverse Effect.

(o)Except as disclosed in the Registration Statement, the Time of Sale Prospectus and the Prospectus, (i) there are no proceedings that are pending, or to the Company’s knowledge, threatened, against the Company or any of its subsidiaries under Environmental Laws in which a governmental authority is also a party, other than such proceedings regarding which it is reasonably believed no monetary sanctions of $100,000 or more will be imposed; (ii) the Company and its subsidiaries are not aware of any issues regarding compliance with Environmental Laws, including any pending or proposed Environmental Laws, or liabilities or other obligations under Environmental Laws or concerning hazardous or toxic substances or wastes, pollutants or contaminants, that could reasonably be expected to have a material effect on the capital expenditures, earnings or competitive position of the Company and its subsidiaries; and (iii) none of the Company and its subsidiaries anticipates material capital expenditures relating to Environmental Laws.

(p)Except as disclosed in the Registration Statement, the Time of Sale Prospectus and the Prospectus, 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 of the Company owned or to be owned by such person. There are no contracts, agreements or understandings to require the Company to register for sale under the Registration Statement or include in the offering contemplated by this Agreement any such securities, except for such contracts, agreements or understandings that have been validly waived in writing prior to the date hereof.

(q)(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 on behalf of the Company or of any of its subsidiaries or controlled affiliates 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 (a) 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) (“Government Official”) in order to influence official action, or (b) to any person, in each of (a) and (b) in violation of any applicable anti-corruption laws; (ii) the Company and each of its subsidiaries and affiliates have conducted their businesses in compliance with applicable anti-corruption laws and have instituted and maintained and will continue to 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)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 (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 best knowledge of the Company, threatened.

(s)(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

(“Control Person”) that is, or is owned or controlled by one or more Control 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 (collectively, “Sanctions”), or

(B) located, organized or resident in a country or territory that is the subject of Sanctions (including, without limitation, the Crimea region of Ukraine, 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 Control Person:

(A) to fund or facilitate any activities or business of or with any Control 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 Control Person (including any Control 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 engage in, any dealings or transactions with any Control Person, or in any country or territory, that at the time of the dealing or transaction is or was the subject of Sanctions.

(t)The Company and, to the knowledge of the Company, its directors, officers, employees and agents (while acting in such capacity) are, and at all times prior to the date hereof have been, in compliance with, all health care laws and regulations applicable to the Company or any of its product candidates or activities, including development and testing of pharmaceutical products, kickbacks, recordkeeping, documentation requirements, the hiring of employees (to the extent governed by Health Care Laws, as defined below), quality, safety, licensure, accreditation or any other aspect of developing and testing health care or pharmaceutical products (collectively, “Health Care Laws”), except where such noncompliance would not, individually or in the aggregate, have a Material Adverse Effect. The Company has not received any notification, correspondence or any other written or oral communication, including notification of any pending or threatened claim, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any governmental authority, including, without limitation, the U.S. Food and Drug Administration (“FDA”), the U.S. Drug Enforcement Administration, the Centers for Medicare & Medicaid Services and the U.S. Department of Health and Human Services Office of Inspector General, of potential or actual non-compliance by, or liability of, the Company under any Health Care Laws. To the Company’s knowledge, there are no facts or circumstances that would reasonably be

expected to give rise to liability of the Company under any Health Care Laws, except that would not individually or in the aggregate have a Material Adverse Effect.

(u)The clinical and pre-clinical trials conducted by or on behalf of or sponsored by the Company, or in which the Company has participated, that are described in the Registration Statement, Time of Sale Prospectus and the Prospectus or the results of which are referred to in the Registration Statement, Time of Sale Prospectus and the Prospectus, were and, if still pending, are being conducted in accordance with standard medical and scientific research procedures and all applicable statutes, rules and regulations of the FDA and comparable drug regulatory agencies outside of the United States to which they are subject (collectively, the “Regulatory Authorities”), including, without limitation, 21 C.F.R. Parts 50, 54, 56, 58 and 312, and current Good Clinical Practices and Good Laboratory Practices; the descriptions in the Registration Statement, Time of Sale Prospectus or the Prospectus of the results of such studies and trials are accurate and complete and fairly present the data derived from such trials; the Company has no knowledge of any other trials the results of which are inconsistent with or otherwise call into question the results described or referred to in the Registration Statement, Time of Sale Prospectus and the Prospectus; the Company and its subsidiaries have each operated and are currently in compliance with all applicable statutes, rules and regulations of the Regulatory Authorities, except where such noncompliance would not, individually or in the aggregate, have a Material Adverse Effect; and neither the Company, nor any of its subsidiaries, has received any written notices, correspondence or other communication from the Regulatory Authorities or any governmental authority which threatens the termination or suspension of any clinical or pre-clinical trials that are described in the Registration Statement, Time of Sale Prospectus or the Prospectus or the results of which are referred to in the Registration Statement, Time of Sale Prospectus or the Prospectus, and there are no reasonable grounds for same.

(v)The Company and its subsidiaries possess all material certificates, authorizations, clearances, approvals, registrations, exemptions, licenses or permits required by state, federal or foreign regulatory agencies or bodies to conduct their respective businesses as currently conducted and as described in the Registration Statement, Time of Sale Prospectus and the Prospectus (“Permits”), and all such Permits are valid, current and in full force and effect, except where the failure to so possess or be valid, current and in full force and effect would not, individually or in the aggregate, reasonably be expected to result in a Material Adverse Effect. Neither the Company nor any of its subsidiaries is in violation of, or in default under, any of the Permits or has received any notice of proceedings relating to the revocation or modification of, or non-compliance with, any such certificate, authorization or permit. Neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification of any Permits which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding, would reasonably be expected to result in a Material Adverse Effect. The Company has not received any written notice denying, revoking or modifying any “approved enterprise,” “benefited enterprise” or “preferred enterprise” status with respect to any of the Company’s facilities or operations.

(w)To the knowledge of the Company, the Company and its subsidiaries own or possess the valid right to use all (i) patents, patent applications, trademarks, trademark registrations, service marks, service mark registrations, internet domain name registrations, copyrights, copyright registrations, licenses and trade secret rights (collectively, “Intellectual Property Rights”) and (ii) inventions, software, works of authorships, trademarks, service marks, trade names, databases, formulae, know how, Internet domain names and other intellectual property (including trade secrets and other unpatented and/or unpatentable proprietary confidential information, systems, or procedures) (collectively, “Intellectual Property Assets”) necessary to conduct their respective businesses as currently conducted, and as proposed to be conducted and described in the Registration Statement, the Time of Sale Prospectus and the Prospectus. The Company and its subsidiaries have not received written notice of any challenge, which is still pending, by any other person to the rights of the Company and its subsidiaries with respect to any Intellectual Property Rights or Intellectual Property Assets owned or used by the Company or its subsidiaries, except as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. To the knowledge of the Company, the Company and its subsidiaries’ respective businesses as now conducted do not give rise to any material infringement of, any material misappropriation of, or other material violation of, any valid and enforceable Intellectual Property Rights of any other person. To the knowledge of the Company, all licenses for the use of the Intellectual Property Rights described in the Registration Statement, the Time of Sale Prospectus and the Prospectus are valid, binding upon and enforceable by or against the parties thereto in accordance with their terms. The Company has complied in all material respects with, and is not in breach nor has received any asserted or threatened claim of material breach of any Intellectual Property license, and the Company has no knowledge of any material breach by any other person to any Intellectual Property license to which the Company is a party. No claim has been made, and is currently pending, against the Company alleging the infringement by the Company of any patent, trademark, service mark, trade name, copyright, trade secret, license in or other Intellectual Property Right or franchise right of any person, and, to the knowledge of the Company, there are no facts that would form a reasonable basis for such claim, except as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. The Company has taken all reasonable steps to protect, maintain and safeguard its Intellectual Property Rights, including the execution of appropriate nondisclosure and confidentiality agreements. The consummation of the transactions contemplated hereby will not result in the loss or impairment of or payment of any additional amounts with respect to, nor require the consent of any other person in respect of, the Company’s right to own, use, or hold for use any of the Intellectual Property Rights as owned, used or held for use in the conduct of the business as currently conducted. To the knowledge of the Company, no employee of Legacy Alpine and, since July 24, 2017, no employee of the Company is in, or has ever been, in violation in any material respect of any term of any employment contract, patent disclosure agreement, invention assignment agreement, non-competition agreement, non-solicitation agreement, non-disclosure agreement or any restrictive covenant to or with a former employer where the basis of such violation relates to such employee’s employment with the Company, or actions undertaken by the employee while employed with the Company. For purposes of this section, “Legacy Alpine” means Alpine Immune Sciences, Inc., which was the

surviving entity following its merger with a wholly-owned subsidiary of Nivalis Therapeutics, Inc. on July 24, 2017 and renamed as AIS Operating Co., Inc.

(x)(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 in all material respects 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.

(y)The Company and each of its subsidiaries (i) are, and at all prior times in the past four (4) years were, in compliance with all applicable data privacy and security laws and regulations, including, as applicable, the Health Insurance Portability and Accountability Act (“HIPAA”), as amended by the Health Information Technology for Economic and Clinical Health Act (42 U.S.C. Section 17921 et seq.), the European Union General Data Protection Regulation (“GDPR”) (EU 2016/679) (collectively, “Privacy Laws”), (ii) have in place, comply with, and take appropriate steps reasonably designed to ensure compliance in all material respects with their policies and procedures relating to data privacy and security and the collection, storage, use, disclosure, handling and analysis of Personal Data (the “Policies”), and (iii) provide accurate notice of their Policies to their respective customers, employees, third party vendors and representatives as required under Privacy Laws, and such Policies provide accurate and sufficient notice of the Company’s then-current privacy practices relating to its subject matter and do not contain any material omissions of the Company’s then-current privacy practices in violation of Privacy Laws, except, in each case of (i) – (iii), as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. “Personal Data” means (i) a natural person’s name, street address, telephone number, email address, photograph, social security number, bank information, or customer or account number; (ii) any information which would qualify as “personally identifying information” under the Federal Trade Commission Act, as amended; (iii) Protected Health Information as defined by HIPAA; (iv) “personal data” as defined by GDPR; and (v) any other piece of information that allows the identification of such natural person, or his or her family by the Company. Except as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect, (i) none of such disclosures made or contained in any of the Policies in the past four (4) years have been inaccurate, misleading, or deceptive in violation of any Privacy Laws, (ii) the execution, delivery and performance of this Agreement or any other agreement referred to in this Agreement will not result in a breach of any Privacy Laws or Policies, and (iii) neither the Company nor any of its subsidiaries, (x) has in the past four (4) years received notice of any actual or potential liability under or relating to, or actual or potential violation of, any of the

Privacy Laws, and has no knowledge of any event or condition that would reasonably be expected to result in any such notice; (y) is currently conducting or paying for, in whole or in part, any investigation, remediation or other corrective action pursuant to any Privacy Law; or (z) is a party to any order, decree, or agreement with any governmental authority that imposed any obligation or liability under any Privacy Law.

(z)In the past four (4) years, (i) there has been no security breach or attack or other compromise of any of the Company’s and its subsidiaries’ information technology and computer systems, networks, hardware, software, technology, equipment, or personal, confidential, or sensitive data (including any such data of their respective customers, employees, suppliers, vendors and any such third party data maintained by or on behalf of them) (“IT Systems and Data”), (ii) the Company and its subsidiaries have not been notified of, and have no knowledge of any event or condition that would reasonably be expected to result in any security breach, attack or compromise to their IT Systems and Data, (iii) the Company and each of its subsidiaries have complied, and are presently in compliance with, all applicable laws, statutes or any applicable judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority and all industry guidelines and standards with which they have represented compliance, and their internal policies and contractual obligations, in each case, relating to the privacy and security of the Company’s IT Systems and Data and to the protection of such IT Systems and Data from unauthorized use, access, misappropriation or modification, and (iv) the Company and each of its subsidiaries have implemented backup and disaster recovery technology consistent with industry standards and practice, except, in each case of (i) – (iv), as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(bb)The historical financial statements (including the related notes and supporting schedules) included or incorporated by reference in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus comply as to form in all material respects with the applicable accounting requirements of the Securities Act and present fairly, in all material respects, the financial condition, results of operations and cash flows of the entities purported to be shown thereby at the dates and for the periods indicated, and such financial statements have been prepared in conformity with generally accepted accounting principles (“U.S. GAAP”) applied on a consistent basis throughout the periods indicated therein, 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, the Time of Sale Prospectus 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 pro forma financial statements and the related notes thereto, if any, included in each of the Registration Statement, the Time of Sale Prospectus and the Prospectus present fairly the information shown therein, have been prepared in accordance with the Commission’s rules and guidelines with respect to pro forma financial statements and have been properly compiled on the bases described therein, and the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions and circumstances referred to therein. The statistical, industry-related and market-related data included in each of the Registration Statement, the Time of Sale Prospectus 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.

(cc)Ernst & Young LLP, who have certified certain financial statements of the Company and its subsidiaries and delivered its report with respect to the audited consolidated financial statements and schedules filed with the Commission as part of the Registration Statement and included in each of the Registration Statement, the Time of Sale Prospectus 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).

(dd)The Company and each of its subsidiaries maintain internal accounting controls designed to provide reasonable assurances regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with U.S. GAAP, including, but not limited to, 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; and (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 (it being understood that this paragraph shall not to require the Company to comply with Section 404 of the Sarbanes-Oxley Act of 2002, as amended, and the rules and regulations promulgated thereunder (collectively, the “Sarbanes-Oxley Act”) as of an earlier date than it would otherwise be required to so comply under applicable law). Since the end of the Company’s most recent audited fiscal year, there has been no material weakness in the Company’s internal control over financial reporting (whether or not remediated).

(ee)The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement is accurate and 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.

(ff)The Company (i) has not alone engaged in any Testing-the-Waters Communication with any person other than Testing-the-Waters Communications with the consent of the Representatives with entities that are reasonably believed to be qualified institutional buyers within the meaning of Rule 144A under the Securities Act or institutions that are reasonably believed to be accredited investors within the meaning of Rule 501 under the Securities Act and (ii) has not authorized anyone to engage in Testing-the-Waters Communications. The Company has not distributed any Testing-the-Waters Communication that is a written communication within the meaning of Rule 405 under the Securities Act other than those listed on Schedule II hereto. “Testing-the-Waters Communication” means any communication with potential investors undertaken in reliance on Section 5(d) or Rule 163B of the Securities Act.

(gg)As of the time of each sale of the Securities in connection with the offering when the Prospectus is not yet available to prospective purchasers, none of (A) the Time of Sale Prospectus, (B) any free writing prospectus, when considered together with the Time of Sale Prospectus, and (C) any individual Testing-the-Waters Communication, when considered together with the Time of Sale Prospectus, included, includes or will include an untrue statement of a material fact or omitted, omits or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(hh)There is and has been no failure on the part of the Company or, to the knowledge of the Company, any of the Company’s directors or officers, in their capacities as such, to comply with any provision of the Sarbanes-Oxley Act that are applicable to the Company or its directors or officers in their capacities as directors or officers of the Company.

On the basis of the representations and warranties contained in this Agreement, and subject to its terms and conditions, the Company agrees to sell to the Underwriters the Additional Shares, and the Underwriters shall have the right to purchase, severally and not jointly, up to 2,040,900 Additional Shares at the Purchase Price, provided, however, that the amount paid by the Underwriters for any Additional Shares shall be reduced by an amount per share equal to any dividends declared by the Company and payable on the Firm Shares but not payable on such Additional Shares. The Representatives may exercise this right on behalf of the Underwriters in whole or from time to time in part by giving written notice not later than 30 days after the date of this Agreement. Any exercise notice shall specify the number of Additional Shares to be purchased by the Underwriters and the date on which such shares are to be purchased. Each purchase date must be at least one business day after the written notice is given and may not be earlier than the closing date for the Firm Shares or later than ten business days

after the date of such notice. Additional Shares may be purchased as provided in Section 4 hereof. On each day, if any, that Additional Shares are to be purchased (an “Option Closing Date”), each Underwriter agrees, severally and not jointly, to purchase the number of Additional Shares (subject to such adjustments to eliminate fractional shares as the Representatives may determine) that bears the same proportion to the total number of Additional Shares to be purchased on such Option Closing Date as the number of Firm Shares set forth in Schedule I hereto opposite the name of such Underwriter bears to the total number of Firm Shares.

3.Terms of Public Offering. The Company is advised by the Representatives that the Underwriters propose to make a public offering of their respective portions of the Securities as soon after this Agreement has become effective as in the judgment of the Representatives is advisable. The Company is further advised by the Representatives that the Securities are to be offered to the public initially at $7.35 a share (the “Public Offering Price”) and to certain dealers selected by the Representatives at a price that represents a concession not in excess of $0.26460 per share.

4.Payment and Delivery. Payment for the Firm Shares shall be made to the Company in Federal or other funds immediately available in New York City against delivery of such Firm Shares for the respective accounts of the several Underwriters at 10:00 a.m., New York City time, on September 23, 2022, or at such other time on the same or such other date, not later than September 30, 2022, as shall be designated in writing by the Representatives. The time and date of such payment are hereinafter referred to as the “Closing Date.”

Payment for any Additional Shares shall be made to the Company in Federal or other funds immediately available in New York City against delivery of such Additional Shares for the respective accounts of the several Underwriters at 10:00 a.m., New York City time, on the date specified in the corresponding notice described in Section 2 or at such other time on the same or on such other date, in any event not later than November 3, 2022, as shall be designated in writing by the Representatives.

The Firm Shares and Additional Shares shall be registered in such names and in such denominations as the Representatives shall request not later than one full business day prior to the Closing Date or the applicable Option Closing Date, as the case may be. The Firm Shares and Additional Shares shall be delivered to the Representatives on the Closing Date or an Option Closing Date, as the case may be, for the respective accounts of the several Underwriters, with any transfer taxes payable in connection with the transfer of the Securities to the Underwriters duly paid, against payment of the Purchase Price therefor.

5.Conditions to the Underwriters’ Obligations. The obligations of the Company to sell the Securities to the Underwriters and the several obligations of the Underwriters to purchase and pay for the Securities on the Closing Date are subject to the condition that the Registration Statement has become effective.

The several obligations of the Underwriters are subject to the following further conditions:

(a)Subsequent to the execution and delivery of this Agreement and prior to the Closing Date:

(i)no order suspending the effectiveness of the Registration Statement shall be in effect, and no proceeding for such purpose or pursuant to Section 8A under the Securities Act shall be pending before or threatened by the Commission;

(ii)there shall not have occurred any downgrading, nor shall any notice have been given of any intended or potential downgrading or of any review for a possible change that does not indicate the direction of the possible change, in the rating accorded any of the securities of the Company or any of its subsidiaries by any “nationally recognized statistical rating organization,” as such term is defined in Section 3(a)(62) of the Exchange Act; and

(iii)there shall not have occurred any change, or any development involving a prospective change, in the condition, financial or otherwise, or in the earnings, business or operations of the Company and its subsidiaries, taken as a whole, from that set forth in the Time of Sale Prospectus that, in the judgment of the Representatives, is material and adverse and that makes it, in the judgment of the Representatives, impracticable to market the Securities on the terms and in the manner contemplated in the Time of Sale Prospectus.

(b)The Underwriters shall have received on the Closing Date a certificate, dated the Closing Date and signed by an executive officer of the Company, to the effect set forth in Sections 5(a)(i) and 5(a)(ii) above and to the effect that the representations and warranties of the Company contained in this Agreement are true and correct as of the Closing Date and that the Company has complied with all of the agreements and satisfied all of the conditions on its part to be performed or satisfied hereunder on or before the Closing Date.

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

(c)The Underwriters shall have received on the Closing Date an opinion and negative assurance letter of Wilson Sonsini Goodrich & Rosati, Professional Corporation, outside counsel for the Company, dated the Closing Date, in the form and substance reasonably satisfactory to the Representatives and to counsel to the Underwriters.

(d)The Underwriters shall have received on the Closing Date an opinion of Morrison & Foerster LLP, outside counsel for the Company with respect to intellectual property matters, dated the Closing Date, in the form and substance reasonably satisfactory to the Representatives and to counsel to the Underwriters.

(e)The Underwriters shall have received on the Closing Date an opinion and negative assurance letter of Latham & Watkins LLP, counsel for the Underwriters, dated the Closing Date, in the form and substance reasonably satisfactory to the Representatives and to counsel to the Company.

(f)The Underwriters shall have received, on each of the date hereof and the Closing Date, a letter dated the date hereof or the Closing Date, as the case may be, in form and substance reasonably satisfactory to the Representatives, from Ernst & Young LLP, independent public accountants, containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the Time of Sale Prospectus and the Prospectus; provided that the letter delivered on the Closing Date shall use a “cut-off date” not earlier than the date hereof.

(g)The “lock-up” agreements, each substantially in the form of Exhibit A hereto, between the Representatives and certain stockholders, officers and directors of the Company relating to restrictions on sales and certain other dispositions of shares of Common Stock or certain other securities, delivered to the Representatives on or before the date hereof, shall be in full force and effect on the Closing Date.

(h)The several obligations of the Underwriters to purchase Additional Shares hereunder are subject to the delivery to the Representatives on the applicable Option Closing Date of the following:

(i)a certificate, dated the Option Closing Date and signed by an executive officer of the Company, confirming that the certificate delivered on the Closing Date pursuant to Section 5(b) hereof remains true and correct as of such Option Closing Date;

(ii)an opinion and negative assurance letter of Wilson Sonsini Goodrich & Rosati, Professional Corporation, outside counsel for the Company, dated the Option Closing Date, relating to the Additional Shares to be purchased on such Option Closing Date and otherwise to the same effect as the opinion required by Section 5(c) hereof;

(iii)an opinion of Morrison & Foerster LLP, outside counsel for the Company with respect to intellectual property matters, dated the Option Closing Date, relating to the Additional Shares to be purchased on such Option Closing Date and otherwise to the same effect as the opinion required by Section 5(d) hereof;

(iv)an opinion and negative assurance letter of Latham & Watkins LLP, counsel for the Underwriters, dated the Option Closing Date, relating to the Additional Shares to be purchased on such Option Closing Date and otherwise to the same effect as the opinion required by Section 5(e) hereof;

(v)a letter dated the Option Closing Date, in form and substance reasonably satisfactory to the Representatives, from Ernst & Young LLP,

independent public accountants, substantially in the same form and substance as the letter furnished to the Underwriters pursuant to Section 5(f) hereof; provided that the letter delivered on the Option Closing Date shall use a “cut-off date” not earlier than two business days prior to such Option Closing Date; and

(vi)such other documents as the Representatives may reasonably request with respect to the good standing of the Company, the due authorization and issuance of the Additional Shares to be sold on such Option Closing Date and other matters related to the issuance of such Additional Shares.

6.Covenants of the Company. The Company covenants with each Underwriter as follows:

(a)To furnish to the Representatives upon request and without charge, five signed copies of the Registration Statement (including exhibits thereto and documents incorporated by reference) and for delivery to each other Underwriter a conformed copy of the Registration Statement (without exhibits thereto but including documents incorporated by reference) and to furnish to the Representatives in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period mentioned in Section 6(e) or 6(f) below, as many copies of the Time of Sale Prospectus, the Prospectus, any documents incorporated by reference therein and any supplements and amendments thereto or to the Registration Statement as the Representatives may reasonably request.

(b)Before amending or supplementing the Registration Statement, the Time of Sale Prospectus or the Prospectus, to furnish to the Representatives a copy of each such proposed amendment or supplement and not to file any such proposed amendment or supplement to which the Representatives reasonably object, and to file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

(c)To furnish to the Representatives a copy of each proposed free writing prospectus to be prepared by or on behalf of, used by, or referred to by the Company and not to use or refer to any proposed free writing prospectus to which the Representatives reasonably object.

(d)Not to take any action that would result in an Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that the Underwriter otherwise would not have been required to file thereunder.

(e)If the Time of Sale Prospectus is being used to solicit offers to buy the Securities at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement then on file, or if, in the

opinion of counsel for the Underwriters, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not, in the light of the circumstances when the Time of Sale Prospectus is delivered to a prospective purchaser, be misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law.

(f)If, during such period after the first date of the public offering of the Securities as in the opinion of counsel for the Underwriters the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is required by law to be delivered in connection with sales by an Underwriter or dealer, any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus in order to make the statements therein, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, not misleading, or if, in the opinion of counsel for the Underwriters, it is necessary to amend or supplement the Prospectus to comply with applicable law, forthwith to prepare, file with the Commission and furnish, at its own expense, to the Underwriters and to the dealers (whose names and addresses the Representatives will furnish to the Company) to which the Securities may have been sold by the Representatives on behalf of the Underwriters and to any other dealers upon request, either amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances when the Prospectus (or in lieu thereof the notice referred to in Rule 173(a) of the Securities Act) is delivered to a purchaser, be misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law.

(g)To endeavor to qualify the Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions as the Representatives shall reasonably request; provided that the foregoing shall not require the Company to qualify to do business in any jurisdiction, execute a general consent to service of process in any jurisdiction, or subject itself to taxation in any jurisdiction in which it is not otherwise subject.

(h)To make generally available to the Company’s security holders and to the Representatives as soon as practicable an earnings statement covering a period of at least twelfth months beginning with the first fiscal quarter of the Company occurring after the date of this Agreement which shall satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder, which requirements may be satisfied by filing on the Commission’s Electronic Data Gathering, Analysis, and Retrieval System.

(i)Whether or not the transactions contemplated in this Agreement are consummated or this Agreement is terminated, the Company agrees to pay or cause to be paid all expenses incident to the performance of its obligations under this Agreement, including: (i) the fees, disbursements and expenses of the Company’s counsel and the

Company’s accountants in connection with the registration and delivery of the Securities under the Securities Act and all other fees or expenses in connection with the preparation and filing of the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company and amendments and supplements to any of the foregoing, including all printing costs associated therewith, and the mailing and delivering of copies thereof to the Underwriters and dealers, in the quantities hereinabove specified, (ii) all costs and expenses related to the transfer and delivery of the Securities to the Underwriters, including any transfer or other taxes payable thereon, (iii) the reasonable and documented cost of printing or producing any Blue Sky or Legal Investment memorandum in connection with the offer and sale of the Securities under state securities laws and all expenses in connection with the qualification of the Securities for offer and sale under state securities laws as provided in Section 6(g) hereof, including filing fees and the reasonable, documented fees and disbursements of counsel for the Underwriters in connection with such qualification and in connection with the Blue Sky or Legal Investment memorandum, (iv) all filing fees and the reasonable fees and disbursements of counsel to the Underwriters incurred in connection with the review and qualification of the offering of the Securities by the Financial Industry Regulatory Authority, provided that the amount of such fees and disbursements of counsel to be paid by the Company pursuant to subsections (iii) and (iv) shall not exceed $35,000 in the aggregate, (v) all costs and expenses incident to listing the Firm Shares and the Additional Shares on the Nasdaq Global Market, (vi) the cost of printing certificates, if any, representing the Securities, (vii) the costs and charges of any transfer agent, registrar or depositary, (viii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the offering of the Securities, including, without limitation, expenses associated with the preparation or dissemination of any electronic road show, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, travel and lodging expenses of the representatives and officers of the Company and any such consultants (not including the Underwriters and their representatives), (ix) the document production charges and expenses associated with printing this Agreement and (x) all other costs and expenses incident to the performance of the obligations of the Company hereunder for which provision is not otherwise made in this Section. It is understood, however, that except as provided in this Section, Section 8 entitled “Indemnity and Contribution” and the last paragraph of Section 10 below, the Underwriters will pay all of their costs and expenses, including fees and disbursements of their counsel, stock transfer taxes payable on resale of any of the Securities by them and any advertising expenses connected with any offers they may make.

(j)If at any time following the distribution of any Testing-the-Waters Communication that is a written communication within the meaning of Rule 405 under the Securities Act there occurred or occurs an event or development as a result of which such Testing-the-Waters Communication included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing at that subsequent time, not misleading, the Company will promptly notify the Representatives and will

promptly amend or supplement, at its own expense, such Testing-the-Waters Communication to eliminate or correct such untrue statement or omission.

The Company also covenants with each Underwriter that, without the prior written consent of the Representatives on behalf of the Underwriters, it will not, and will not publicly disclose an intention to, during the period ending 60 days after the date of the Prospectus (the “Restricted Period”), (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock, or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise or (3) file any registration statement with the Commission relating to the offering of any shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock. The restrictions contained in the foregoing sentence shall not apply to (A) the Securities to be sold hereunder, (B) the issuance by the Company of shares of Common Stock upon the exercise (including any “net” or “cashless” exercise) of an option or warrant or the conversion of a security outstanding on the date hereof and described in the Time of Sale Prospectus and Prospectus, (C) the issuance by the Company of options, restricted stock units or other equity awards (including the Common Stock issued upon the settlement or exercise thereof) to service providers of the Company pursuant to employee benefit or equity incentive plans described the Time of Sale Prospectus and the Prospectus or pursuant to any applicable inducement grants made in compliance with applicable Nasdaq rules, (D) the filing by the Company of registration statements on Form S-8 with respect to employee benefit plans (including any employee benefit plans assumed pursuant to clause (H)) or inducement equity grants made in compliance with the rules of the Nasdaq Global Market, (E) facilitating the establishment of a trading plan on behalf of a stockholder, officer or director of the Company pursuant to Rule 10b5-1 under the Exchange Act, for the transfer of shares of Common Stock, provided that (i) such plan does not provide for the transfer of Common Stock during the Restricted Period and (ii) to the extent a public announcement or filing under the Exchange Act, if any, is required of or voluntarily made by the Company regarding the establishment of such plan, such announcement or filing shall include a statement to the effect that no transfer of Common Stock may be made under such plan during the Restricted Period, (F) the filing of any shelf registration statement, (G) the establishment of an “at-the-market” offering program or amendment of any such existing program, including the filing of any prospectus supplement or amendment relating to such program, provided that no shares may be offered or sold pursuant to such at-the-market offering during the Restricted Period or (H) the issuance by the Company of shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock in connection with (1) the acquisition by the Company or any of its subsidiaries of the securities, business, technology, property or other assets of another person or entity or pursuant to an employee benefit plan assumed by the Company in connection with such acquisition, (2) the Company’s joint ventures, equipment leasing arrangements, licensing arrangements, collaborations, debt financings

and other strategic transactions, provided that the aggregate number of shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock that the Company may sell or issue or agree to sell or issue pursuant to this clause (H) shall not exceed 5% of the total number of shares of Common Stock outstanding immediately following the completion of the transactions contemplated by this Agreement (including the Additional Shares), if and to the extent so issued.

7.Covenants of the Underwriters. Each Underwriter, severally and not jointly, covenants with the Company not to take any action that would result in the Company being required to file with the Commission under Rule 433(d) a free writing prospectus prepared by or on behalf of such Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter.

8.Indemnity and Contribution. (a) The Company agrees to indemnify and hold harmless each Underwriter, each person, if any, who controls any Underwriter within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act and each affiliate of any Underwriter within the meaning of Rule 405 under the Securities Act from and against any and all losses, claims, damages and liabilities (including, without limitation, any legal or other expenses reasonably incurred in connection with defending or investigating any such action or claim) that arise out of, or are based upon, any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or any amendment thereof, any preliminary prospectus, the Time of Sale Prospectus or any amendment or supplement thereto, any issuer free writing prospectus as defined in Rule 433(h) under the Securities Act, any Company information that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act, any “road show” as defined in Rule 433(h) under the Securities Act (a “road show”), the Prospectus or any amendment or supplement thereto, or any Testing-the-Waters Communication, or arise out of, or are based upon, any omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, except insofar as such losses, claims, damages or liabilities arise out of, or are based upon, any such untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use therein, it being understood and agreed that the only such information furnished by the Underwriters through the Representatives consists of the information described as such in paragraph (b) below.

(b)Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, its directors, its officers who sign the Registration Statement and each person, if any, who controls the Company within the meaning of either Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as the foregoing indemnity from the Company to such Underwriter, but only with reference to information relating to such Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any issuer free writing prospectus, road show, or the Prospectus or any amendment or supplement thereto. For

the purpose of this Agreement, the only information so furnished shall be the information contained in the first sentence of the third paragraph, the twelfth paragraph and the sixteenth paragraph, in each case, under the caption “Underwriting” in the Prospectus.

(c)In case any proceeding (including any governmental investigation) shall be instituted involving any person in respect of which indemnity may be sought pursuant to Section 8(a) or 8(b), such person (the “indemnified party”) shall promptly notify the person against whom such indemnity may be sought (the “indemnifying party”) in writing and the indemnifying party, upon request of the indemnified party, shall retain counsel reasonably satisfactory to the indemnified party to represent the indemnified party and any others the indemnifying party may designate in such proceeding and shall pay the reasonably incurred fees and disbursements of such counsel related to such proceeding. In any such proceeding, any indemnified party shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such indemnified party unless (i) the indemnifying party and the indemnified party shall have mutually agreed in writing to the retention of such counsel or (ii) the named parties to any such proceeding (including any impleaded parties) include both the indemnifying party and the indemnified party and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood that the indemnifying party shall not, in respect of the legal expenses of any indemnified party in connection with any proceeding or related proceedings in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all such indemnified parties and that all such fees and expenses shall be reimbursed as they are incurred. Such firm shall be designated in writing by the Representatives, in the case of parties indemnified pursuant to Section 8(a), and by the Company, in the case of parties indemnified pursuant to Section 8(b). The indemnifying party shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party from and against any loss or liability by reason of such settlement or judgment. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened proceeding in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party, unless such settlement includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such proceeding.

(d)To the extent the indemnification provided for in Section 8(a) or 8(b) is unavailable to an indemnified party or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each indemnifying party under such paragraph, in lieu of indemnifying such indemnified party thereunder, shall contribute to the amount paid or payable by such indemnified party as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Securities or (ii) if the allocation provided by clause 8(d)(i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause 8(d)(i) above but also the relative fault

of the Company on the one hand and of the Underwriters on the other hand in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other hand in connection with the offering of the Securities shall be deemed to be in the same respective proportions as the net proceeds from the offering of the Securities (before deducting expenses) received by the Company and the total underwriting discounts and commissions received by the Underwriters, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate Public Offering Price of the Securities. The relative fault of the Company on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The Underwriters’ respective obligations to contribute pursuant to this Section 8 are several in proportion to the respective number of Securities they have purchased hereunder, and not joint.

(e)The Company and the Underwriters agree that it would not be just or equitable if contribution pursuant to this Section 8 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in Section 8(d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages and liabilities referred to in Section 8(d) shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions of this Section 8, no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The remedies provided for in this Section 8 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any indemnified party at law or in equity.

(f)The indemnity and contribution provisions contained in this Section 8 and the representations, warranties and other statements of the Company contained in this Agreement shall remain operative and in full force and effect regardless of (i) any termination of this Agreement, (ii) any investigation made by or on behalf of any Underwriter, any person controlling any Underwriter or any affiliate of any Underwriter or by or on behalf of the Company, its officers or directors or any person controlling the Company and (iii) acceptance of and payment for any of the Securities.

9.Termination. The Underwriters may terminate this Agreement by notice given by the Representatives to the Company, if after the execution and delivery of this

Agreement and prior to or on the Closing Date or, with respect to any Option Closing, prior to or on such Option Closing Date, as the case may be, (i) trading generally shall have been suspended or materially limited on, or by, as the case may be, either of the New York Stock Exchange or the Nasdaq Global Market, (ii) trading of any securities of the Company shall have been suspended on any exchange or in any over-the-counter market, (iii) a material disruption in securities settlement, payment or clearance services in the United States shall have occurred, (iv) any moratorium on commercial banking activities shall have been declared by Federal or New York State authorities or (v) there shall have occurred any outbreak or escalation of hostilities, or any change in financial markets or any calamity or crisis that, in the judgment of the Representatives, is material and adverse and which, singly or together with any other event specified in this clause (v), makes it, in the judgment of the Representatives, impracticable or inadvisable to proceed with the offer, sale or delivery of the Securities on the terms and in the manner contemplated in the Time of Sale Prospectus or the Prospectus.

10.Effectiveness; Defaulting Underwriters. This Agreement shall become effective upon the execution and delivery hereof by the parties hereto.

If, on the Closing Date or an Option Closing Date, as the case may be, any one or more of the Underwriters shall fail or refuse to purchase Securities that it has or they have agreed to purchase hereunder on such date, and the aggregate number of Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase is not more than one-tenth of the aggregate number of the Securities to be purchased on such date, the other Underwriters shall be obligated severally in the proportions that the number of Firm Shares set forth opposite their respective names in Schedule I bears to the aggregate number of Firm Shares set forth opposite the names of all such non-defaulting Underwriters, or in such other proportions as the Representatives may specify, to purchase the Securities which such defaulting Underwriter or Underwriters agreed but failed or refused to purchase on such date; provided that in no event shall the number of Securities that any Underwriter has agreed to purchase pursuant to this Agreement be increased pursuant to this Section 10 by an amount in excess of one-ninth of such number of Securities without the written consent of such Underwriter. If, on the Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Securities and the aggregate number of Securities with respect to which such default occurs is more than one-tenth of the aggregate number of Securities to be purchased on such date, and arrangements satisfactory to the Representatives and the Company for the purchase of such Securities are not made within 36 hours after such default, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter or the Company. In any such case either the Representatives or the Company shall have the right to postpone the Closing Date, but in no event for longer than seven days, in order that the required changes, if any, in the Registration Statement, in the Time of Sale Prospectus, in the Prospectus or in any other documents or arrangements may be effected. If, on an Option Closing Date, any Underwriter or Underwriters shall fail or refuse to purchase Additional Shares and the aggregate number of Additional Shares with respect to which such default occurs is more than one-tenth of the aggregate number of Additional Shares to be purchased on such Option Closing Date, the non-defaulting Underwriters shall have the option to (i) terminate their obligation hereunder to purchase the Additional Shares to

be sold on such Option Closing Date or (ii) purchase not less than the number of Additional Shares that such non-defaulting Underwriters would have been obligated to purchase in the absence of such default. Any action taken under this paragraph shall not relieve any defaulting Underwriter from liability in respect of any default of such Underwriter under this Agreement.

If this Agreement shall be terminated by the Underwriters, or any of them, because of any failure or refusal on the part of the Company to comply with the terms or to fulfill any of the conditions of this Agreement, or if for any reason the Company shall be unable to perform its obligations under this Agreement, the Company will reimburse the Underwriters or such Underwriters as have so terminated this Agreement with respect to themselves, severally, for all out-of-pocket expenses (including the reasonable fees and disbursements of their counsel) reasonably incurred by such Underwriters in connection with this Agreement or the offering contemplated hereunder.

11.Entire Agreement. (a) This Agreement, together with any contemporaneous written agreements and any prior written agreements (to the extent not superseded by this Agreement) that relate to the offering of the Securities, represents the entire agreement between the Company and the Underwriters with respect to the preparation of any preliminary prospectus, the Time of Sale Prospectus, the Prospectus, the conduct of the offering, and the purchase and sale of the Securities.

(b)The Company acknowledges that in connection with the offering of the Securities: (i) the Underwriters have acted at arm’s length, are not agents of, and owe no fiduciary duties to, the Company or any other person, (ii) the Underwriters owe the Company only those duties and obligations set forth in this Agreement, any contemporaneous written agreements and prior written agreements (to the extent not superseded by this Agreement), if any, (iii) the Underwriters may have interests that differ from those of the Company, and (iv) none of the activities of the Underwriters in connection with the transactions contemplated herein constitutes a recommendation, investment advice, or solicitation of any action by the Underwriters with respect to any entity or natural person. The Company waives to the full extent permitted by applicable law any claims it may have against the Underwriters arising from an alleged breach of fiduciary duty in connection with the offering of the Securities.

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

(b)In the event that any Underwriter that is a Covered Entity or a BHC Act Affiliate of such Underwriter becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights under this Agreement that may be exercised against such Underwriter are permitted to be exercised to no greater extent than such Default

Rights could be exercised under the U.S. Special Resolution Regime if this Agreement were governed by the laws of the United States or a state of the United States.

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

13.Counterparts. This Agreement may be signed in two or more counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument.

14.Applicable Law. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York.

15.Headings. The headings of the sections of this Agreement have been inserted for convenience of reference only and shall not be deemed a part of this Agreement.

16.Notices. All communications hereunder shall be in writing and effective only upon receipt and if to the Underwriters shall be delivered, mailed or sent to Morgan Stanley & Co. LLC at 1585 Broadway, New York, New York 10036, Attention: Equity Syndicate Desk, with a copy to the Legal Department, SVB Securities LLC at 1301 Avenue of the Americas, 12th Floor, New York, New York 10019 and Cowen and Company LLC, Attention: Head of Equity Capital Markets, Fax: 646 ###-###-#### with a copy to the General Counsel, Fax: 646 ###-###-####; and if to the Company shall be delivered, mailed or sent to 188 East Blaine Street, Suite 200, Seattle, Washington 98102, Attention: Chief Financial Officer, with a copy (which shall not constitute notice) to Wilson Sonsini Goodrich & Rosati, P.C., 701 Fifth Avenue, Suite 5100, Seattle, Washington 98104, Attention: Patrick Schultheis, Michael Nordtvedt and Bryan King.

The undersigned understands that Morgan Stanley & Co. LLC (“Morgan Stanley”), SVB Securities LLC (“SVB Securities”) and Cowen and Company LLC (“Cowen,” and together with Morgan Stanley and SVB Securities, the “Representatives”) propose to enter into an Underwriting Agreement (the “Underwriting Agreement”) with Alpine Immune Sciences, Inc., a Delaware corporation (the “Company”), providing for the public offering (the “Public Offering”) by the several Underwriters named in Schedule I to such agreement, including Morgan Stanley, SVB Securities and Cowen (collectively, the “Underwriters”), of equity securities of the Company (the “Securities”).

To induce the Underwriters that may participate in the Public Offering to continue their efforts in connection with the Public Offering, the undersigned hereby agrees that, without the prior written consent of the Representatives on behalf of the Underwriters, it will not, and will not publicly disclose an intention to, during the period commencing on the date hereof and ending 60 days after the date of the prospectus supplement (the “Restricted

Period”) relating to the Public Offering, (1) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any shares of common stock, par value $0.001 per share, of the Company (the “Common Stock”) beneficially owned (as such term is used in Rule 13d-3 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), by the undersigned or any other securities so owned convertible into or exercisable or exchangeable for Common Stock (collectively, the “Restricted Securities”) or (2) enter into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of the Common Stock, whether any such transaction described in clause (1) or (2) above is to be settled by delivery of Common Stock or such other securities, in cash or otherwise.

The restrictions set forth in the foregoing paragraph shall not apply to:

(1)    any transfers made by the undersigned (a) as a bona fide gift or gifts, (b) by will or other testamentary document or intestate succession upon the death of the undersigned, (c) to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (as defined below), or (d) that occur by operation of law, such as pursuant to a domestic relations order or pursuant to a settlement agreement in connection with a domestic relations matter and such transfer is not for value;

(2)    if the undersigned is a corporation, partnership, limited liability company or other business entity, any transfers or distributions to any stockholder, partner or member of, or owner of a similar equity interest in, the undersigned, as the case may be, if, in any such case, such transfer is not for value;

(3)    if the undersigned is a corporation, partnership, trust, limited liability company or other similar entity, any transfer made by the undersigned (a) in connection with the sale or other bona fide transfer in a single transaction of all or substantially all of the undersigned’s capital stock, partnership interests, membership interests or other similar equity interests, as the case may be, or all or substantially all of the undersigned’s assets, in any such case not undertaken for the purpose of avoiding the restrictions imposed by this agreement, or (b) to another corporation, partnership, limited liability company or other business entity so long as the transferee is an affiliate (as defined below) of the undersigned and such transfer is not for value;

(4)    transactions relating to Common Stock or other securities convertible into or exercisable or exchangeable for Common Stock acquired in the Public Offering or open market transactions after the completion of the Public Offering, provided that, prior to the expiration of the Restricted Period, no filing under the Exchange Act or other public announcement shall be made voluntarily in connection with subsequent sales of Common Stock or other securities acquired in the Public Offering or such open market transactions;

(5)    the sale of the Company’s securities pursuant to a plan, contract or instruction that satisfies all of the requirements of Rule 10b5-1(c)(1)(i)(B) (a “10b5-1 Plan”) under the Exchange Act that was in effect prior to the date hereof; provided, however, to the extent a public announcement or filing under the Exchange Act, if any, is required or voluntarily made by or on behalf of the undersigned or the Company regarding the sales of shares pursuant to such 10b5-1 Plan, such announcement or filing shall state that such sales have been executed under a trading plan pursuant to Rule 10b5-1 under the Exchange Act and shall also state the date such trading plan was adopted;

(6)    the entry by the undersigned, at any time on or after the date of the Underwriting Agreement, into any 10b5-1 Plan, provided, however, that such 10b5-1 Plan does not provide for, or permit, the sale of any Common Stock during the Restricted Period, and to the extent a public announcement or filing under the Exchange Act, if any, is required of or voluntarily made by or on behalf of the undersigned or the Company regarding the establishment of such 10b5-1 Plan, such announcement or filing shall include a statement to the effect that no transfer of Common Stock may be made under such plan during the Restricted Period; and

(7)    the transfer of shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock pursuant to a bona fide third party tender offer, merger, consolidation or other similar transaction made to all holders of the Common Stock involving a change of control of the Company (as defined below) occurring after the consummation of the Public Offering, that has been approved by the board of directors of the Company, provided, that if the tender offer, merger, consolidation or other such transaction is not completed, the Common Stock owned by the undersigned shall remain subject to the restrictions contained in this letter agreement;

provided, however, that in the case of any transfer described in clauses (1)(a), 1(b), 1(c), (2) or (3) above, it shall be a condition to the transfer that (A) the transferee executes and delivers to the Representatives not later than one business day prior to such transfer, a written agreement, in substantially the form of this agreement and otherwise satisfactory in form and substance to the Representatives, and (B) in the case of any transfer described in clause (1), (2), or (3) above, no public announcement or filing under the Exchange Act is voluntarily made regarding such transfer during the Restricted Period, and if the undersigned is required to file a report under Section 16(a) of the Exchange Act reporting a reduction in beneficial ownership of shares of Common Stock or any securities convertible into or exercisable or exchangeable for Common Stock during the Restricted Period, such filing shall clearly indicate in the footnotes thereto that the filing relates to the circumstances described above, as applicable.

For purposes of this agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin; “affiliate” shall have the meaning set forth in Rule 405 under the Securities Act; and “change of control” means the

consummation of any bona fide third party tender offer, merger, consolidation or other similar transaction the result of which is that any “person” (as defined in Section 13(d)(3) of the Exchange Act), or group of persons, other than the Company, becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 of the Exchange Act) of more than 50% of total voting power of the voting stock of the Company.

[If the Representatives release any officer, director or beneficial owner of 1% or more of the outstanding shares of Common Stock as of the date of the Underwriting Agreement (calculated assuming conversion of all outstanding shares of the Company’s preferred stock), other than the undersigned, from the restrictions described herein during the Restricted Period, then the undersigned shall also be granted an early release from its obligations hereunder, on a pro rata basis with all other beneficial owners of similarly restricted securities of the Company based on the maximum percentage of shares held by any such beneficial owner being released from such holder’s lock-up agreement (the “Pro-rata Release”); provided, however, that no Pro-rata Release of the undersigned’s Shares will occur unless the Representatives waived such prohibitions with respect to Common Stock, or any securities convertible into or exercisable for Common Stock, valued at $1,000,000 or more in the aggregate, in one or a series of similar transactions (based on the closing or last reported sale price of the Common Stock on the date such waiver becomes effective). The Pro-rata Release shall not be applied in the case of (1) a release effective solely to permit a transfer not involving a disposition for value if the transferee agrees in writing to be bound by the same terms described in this agreement or (2) an early release from the restrictions described herein during the Restricted Period in connection with an underwritten public offering that is wholly or partially a secondary offering of Shares, provided that the undersigned, to the extent the undersigned has a contractual right to demand or require the registration of the undersigned’s Common Stock or otherwise “piggyback” on a registration statement filed by the Company for the offer and sale of its Common Stock, shall be offered the opportunity to participate on a pro rata basis consistent with such contractual rights in such follow-on offering and on pricing terms that are no less favorable than the terms of the follow-on offering. The Representatives shall use commercially reasonable efforts to provide notice to the Company within two (2) business days prior to the effective date of a release of a stockholder of its obligations under any lock-up agreement executed in connection with the follow-on offering that gives rise to a corresponding release of the undersigned from its obligations hereunder pursuant to the terms of this paragraph, and the Company, in turn, shall notify the undersigned within two (2) business days thereafter that the same percentage of Common Stock held by the undersigned has been released from the restrictions set forth in this agreement, provided that the failure to give such notice to the Representatives or the undersigned shall not give rise to any claim or liability against the Representatives or the Company. The undersigned further acknowledges that the Representatives are under no obligation to inquire whether, or to ensure that, the Company notifies the undersigned of the delivery by the Representatives of any such notice. For purposes of determining beneficial ownership of a stockholder, all shares of Common Stock held by investment funds affiliated with such stockholder shall be aggregated.]

For avoidance of doubt, nothing in this agreement prohibits the undersigned from exercising any options or warrants to purchase Common Stock (which exercises may be effected on a net exercise or cashless basis with the Company to the extent the instruments representing such options or warrants permit exercises on a net exercise or cashless basis to pay the exercise price and/or withholding tax and remittance obligations), or receiving shares of Common Stock, or securities convertible into or exercisable or exchangeable for Common Stock, upon the vesting of restricted stock units (including a net withholding of shares by the Company in connection with such vesting to pay the withholding tax and remittance obligations), it being understood that any Common Stock issued upon such exercises or vesting will be subject to the restrictions of this Agreement and provided, however, that no public announcement or filing is voluntarily made regarding such exercise during the Lock-Up Period and provided that if the undersigned is required to file a report under Section 16(a) of the Exchange Act reporting a reduction in beneficial ownership of such options or warrants or restricted stock units during the Restricted Period, the undersigned shall include a statement in such report to the effect that the disposition relates to the exercise of an option or warrant or vesting of restricted stock units, as applicable, and that the shares of Common Stock received upon exercise are subject to the restrictions of this agreement.

In addition, the undersigned agrees that, without the prior written consent of the Representatives on behalf of the Underwriters, it will not, during the Restricted Period, make any demand for or exercise any right with respect to, the registration of any shares of Common Stock or any security convertible into or exercisable or exchangeable for Common Stock. The undersigned also agrees and consents to the entry of stop transfer instructions with the Company’s transfer agent and registrar against the transfer of the undersigned’s shares of Common Stock except in compliance with the foregoing restrictions.

The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this agreement. The undersigned understands that the Company and the Underwriters are relying upon this agreement in proceeding toward consummation of the Public Offering. The undersigned further understands that this agreement is irrevocable and shall be binding upon the undersigned’s heirs, legal representatives, successors and assigns.

The undersigned acknowledges and agrees that the Underwriters have not provided any recommendation or investment advice nor have the Underwriters solicited any action from the undersigned with respect to the Public Offering of the Securities and the undersigned has consulted their own legal, accounting, financial, regulatory and tax advisors to the extent deemed appropriate. The undersigned further acknowledges and agrees that, although the Underwriters may provide certain Regulation Best Interest and Form CRS disclosures or other related documentation to you in connection with the Public Offering, the Underwriters are not making a recommendation to you to participate in the Public Offering or sell any Securities at the price determined in the Public Offering, and nothing set forth in such disclosures or documentation is intended to suggest that any Underwriter is making such a recommendation.

Whether or not the Public Offering actually occurs depends on a number of factors, including market conditions. Any Public Offering will only be made pursuant to an Underwriting Agreement, the terms of which are subject to negotiation among the parties thereto.

This agreement may be executed and delivered via facsimile, electronic mail (including .pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., www.docusign.com or www.echosign.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.

Notwithstanding the foregoing, this agreement shall terminate and the undersigned shall be released from all obligations under this agreement upon the earliest to occur of (1) September 30, 2022 in the event that the Underwriting Agreement has not been executed by such date, (2) if prior to the execution of the Underwriting Agreement, the Company notifies the Representative in writing that it does not intend to proceed with the Public Offering, and (3) if the Underwriting Agreement (other than the provisions thereof which survive termination) shall terminate or be terminated prior to payment for and delivery of any securities to be sold thereunder.

This agreement shall be governed by and construed in accordance with the laws of the State of New York.