Astria Therapeutics : - 2024 Proxy Statement

ASTRIA THERAPEUTICS, INC.

75 State Street, Suite 1400

Boston, MA 02109

NOTICE OF 2024 ANNUAL MEETING OF STOCKHOLDERS

To be held on June 5, 2024

You are cordially invited to attend the 2024 Annual Meeting of Stockholders of Astria Therapeutics, Inc. (the "Annual Meeting"), which is scheduled to be held at the offices of Wilmer Cutler Pickering Hale and Dorr LLP at 60 State Street, Boston, Massachusetts 02109 on June 5, 2024, at 8:00 a.m. Eastern Time.

At the Annual Meeting, stockholders will consider and vote on the following matters:

1. The election of three Class III Directors to our Board of Directors, to serve for a three-year term until the 2027 annual meeting of stockholders;
2. The approval of the second amendment and restatement of our Amended and Restated 2015 Stock Incentive Plan, as amended, to, among other things, increase the number of shares of our common stock available for grant under the plan by 5,750,000 shares and extend the term of the plan to ten years from the date such second amendment and restatement is approved by our stockholders;
3. The ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024;
4. The approval, by non-binding advisory vote, of our executive compensation; and
5. The transaction of any other business properly brought before the Annual Meeting or any continuation, adjournment or postponement thereof.

You can find more information, including the nominees for directors, in the attached proxy statement. The Board of Directors recommends that you vote in favor of each of the director nominees and proposals two through four as outlined in the attached proxy statement.

Pursuant to rules adopted by the Securities and Exchange Commission, we have elected to make our proxy materials available to all of our stockholders over the Internet. On or about April 22, 2024, we will commence sending to our stockholders a Notice of Internet Availability of Proxy Materials (the "Notice"), containing instructions on how to access our proxy statement for the Annual Meeting and our Annual Report on Form 10-K for the year ended December 31, 2023 ("2023 Annual Report"). The Notice will also provide instructions on how to receive a paper copy of our proxy materials, including this proxy statement, our 2023 Annual Report and a form of proxy card.

We invite all stockholders to attend the Annual Meeting in person. Stockholders of record that hold common stock at the close of business on April 9, 2024, the record date for the Annual Meeting, are entitled to notice of, and to vote at, the Annual Meeting or any continuation, adjournment or postponement of the Annual Meeting.

Whether or not you expect to attend the Annual Meeting in person, please vote your shares by proxy as promptly as possible to ensure your representation and the presence of a quorum at the Annual Meeting.

Most stockholders can vote over the Internet. In addition, if you received a paper copy of the proxy statement in the mail, you may also vote by telephone or by returning a proxy card. Your vote is important regardless of the number of shares you own. If you vote by the Internet or by telephone or send in your proxy card and then decide to attend the Annual Meeting to vote your shares in person, you may still do so. Your proxy is revocable in accordance with the procedures set forth in the proxy statement. If your shares are held in "street name," that is, held for your account by a broker or other nominee, you will receive instructions from the holder of record that you must follow for your shares to be voted.

By order of the Board of Directors,

Jill C. Milne, Ph.D.

President and Chief Executive Officer

Boston, Massachusetts

April 22, 2024

Astria Therapeutics, Inc.
Proxy Statement
Table of Contents
PROXY STATEMENT	1
IMPORTANT INFORMATION ABOUT THE ANNUAL MEETING AND VOTING	2
PROPOSAL NO. 1 - ELECTION OF CLASS III DIRECTORS	7
CORPORATE GOVERNANCE	11
EXECUTIVE OFFICERS	21
EXECUTIVE COMPENSATION	23
PROPOSAL NO. 2 - APPROVAL OF THE SECOND AMENDMENT AND RESTATEMENT
OF THE 2015 PLAN	34
PROPOSAL NO. 3 - RATIFICATION OF THE APPOINTMENT OF ERNST & YOUNG LLP
AS ASTRIA'S INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR THE
FISCAL YEAR ENDING DECEMBER 31, 2024	45
PROPOSAL NO. 4 - ADVISORY VOTE ON EXECUTIVE COMPENSATION	47
PRINCIPAL STOCKHOLDERS	48
CERTAIN RELATIONSHIPS AND RELATED PERSON TRANSACTIONS	51
REPORT OF THE AUDIT COMMITTEE	54
HOUSEHOLDING	55
STOCKHOLDER PROPOSALS	56
OTHER MATTERS	57
APPENDIX A - SECOND AMENDED AND RESTATED 2015 STOCK INCENTIVE PLAN . .	A-1

ASTRIA THERAPEUTICS, INC.

75 State Street, Suite 1400

Boston, MA 02109

617-349-1971

PROXY STATEMENT

FOR THE 2024 ANNUAL MEETING OF STOCKHOLDERS

To be held on June 5, 2024

This proxy statement contains information about the 2024 Annual Meeting of Stockholders of Astria Therapeutics, Inc. (the "Annual Meeting"), which is scheduled to be held at the offices of Wilmer Cutler Pickering Hale and Dorr LLP at 60 State Street, Boston, Massachusetts 02109 on June 5, 2024, at 8:00 a.m. Eastern Time. The Board of Directors of Astria Therapeutics, Inc. is using this proxy statement to solicit proxies for use at the Annual Meeting. In this proxy statement, unless expressly stated otherwise or the context otherwise requires, the use of "Astria," "Company," "our," "we" or "us" refers to Astria Therapeutics, Inc.

All properly submitted proxies will be voted in accordance with the instructions contained in those

proxies. If no instructions are specified, the proxies will be voted in accordance with the recommendation of our Board of Directors with respect to each of the matters set forth in the accompanying Notice of Annual Meeting. You may revoke your proxy at any time before it is exercised during the Annual Meeting by giving our corporate secretary written notice to that effect.

Our Annual Report to Stockholders for the fiscal year ended December 31, 2023, and this proxy statement and proxy card are first being made available to stockholders on or about April 22, 2024.

Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Stockholders to be

Held on June 5, 2024:

This proxy statement and our 2023 Annual Report to Stockholders are available for viewing, printing and

downloading at https://www.viewproxy.com/ATXS/2024.

A copy of our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, as filed with the Securities and Exchange Commission ("SEC") on March 4, 2024 (the "2023 Annual Report on Form 10-K"), except for exhibits, will be furnished without charge to any stockholder upon written request to Astria Therapeutics, Inc., Attention: Corporate Secretary, 75 State Street, Suite 1400, Boston, MA 02109. This proxy statement and our 2023 Annual Report on Form 10-K are also available on the SEC's website at www.sec.gov and our website at www.astriatx.com.

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IMPORTANT INFORMATION ABOUT THE ANNUAL MEETING AND VOTING

Purpose of the Annual Meeting

At the Annual Meeting, our stockholders will consider and vote on the following matters:

1. The election of three Class III Directors to our Board of Directors, to serve for a three-year term until the 2027 annual meeting of stockholders;
2. The approval of the second amendment and restatement of our existing Amended and Restated 2015 Stock Incentive Plan, as amended (the "2015 Plan", and as further amended and restated, the "Second Amended and Restated 2015 Plan") to, among other things, increase the number of shares of our common stock available for grant under the plan by 5,750,000 shares and extend the term of the plan to ten years from the date such second amendment and restatement is approved by our stockholders;
3. The ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024;
4. The approval, by non-binding advisory vote, of our executive compensation; and
5. The transaction of any other business properly brought before the Annual Meeting or any continuation, adjournment or postponement thereof.

As of the date of this proxy statement, we are not aware of any business to come before the Annual Meeting other than the first four matters noted above.

Board of Directors Recommendation

Our Board of Directors unanimously recommends that you vote:

FOR the election of the three nominees to serve as Class III Directors on our Board of Directors for a three-year term until the 2027 annual meeting of stockholders;

FOR the approval of the Second Amended and Restated 2015 Plan;

FOR the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024; and

FOR the approval, on an advisory basis, of our executive compensation.

Notice of Internet Availability of Proxy Materials

Pursuant to rules adopted by the SEC, we have elected to provide access to our proxy materials via the Internet. Accordingly, we are sending a Notice of Internet Availability of Proxy Materials (the "Notice") to our stockholders.

All stockholders will have the ability to access the proxy materials on the website referenced in the Notice and to request to receive a printed set of the proxy materials by mail. Instructions on how to access the proxy materials over the Internet and how to request a printed copy may be found in the Notice. In addition, stockholders may request to receive proxy materials in printed form by mail or electronically by email on an ongoing basis. We encourage stockholders to take advantage of the availability of the proxy materials on the Internet or through email to help reduce the environmental impact of our annual meetings. This proxy statement and our 2023 Annual Report on Form 10-K are also available for viewing, printing and downloading on the Internet at https://www.viewproxy.com/ATXS/2024

Who Can Vote at the Annual Meeting

Only stockholders of record of common stock at the close of business on the record date of April 9, 2024, are entitled to receive notice of the Annual Meeting and to vote the shares of our common stock that they held on that date. As of the record date, there were 54,913,061 shares of common stock issued and

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outstanding. Each share of common stock is entitled to one vote on each matter properly brought before the Annual Meeting. On the record date, we also had 31,107 shares of Series X Preferred Stock (which were convertible into 5,184,591 shares of common stock) issued and outstanding. The Series X Preferred Stock is not entitled to vote on the matters being considered at the Annual Meeting.

Difference between a "stockholder of record" and a beneficial owner of shares held in "street name"

Stockholder of Record. If you have shares of common stock registered directly in your name with our transfer agent, Equiniti Trust Company, LLC, then you are considered a "stockholder of record" of those shares. For these shares, your set of proxy materials has been made available to you directly by us. You may vote these shares by proxy prior to the Annual Meeting by following the instructions contained on the Notice or proxy card.

Beneficial Owner of Shares Held in Street Name. If you hold shares of common stock in a brokerage account or through a bank, trust or other nominee or custodian, then you are considered the beneficial owner of those shares, which are held in "street name." For these shares, your set of proxy materials has been made available to you by that organization. The organization holding your account is considered the stockholder of record for purposes of voting at the Annual Meeting. As the beneficial owner, you have the right to instruct that organization as to how to vote the shares of common stock held in your account by following the instructions contained on the Notice or the voting instruction card provided to you by that organization.

How to Attend the Annual Meeting

The Annual Meeting is open to all of our stockholders and will be held in person. To attend the Annual Meeting, you will need to register upon arrival. We may also check for your name on our stockholders' list and ask you to produce valid identification. If your shares are held in "street name" by your broker or bank, you should bring your most recent brokerage account statement or other evidence of your share ownership. If we cannot verify that you own shares of our common stock, it is possible that you will not be admitted to the Annual Meeting.

We strongly urge stockholders to submit a proxy to vote your shares in advance of the Annual Meeting by submitting a proxy card, or by voting on the Internet or over the telephone.

Submitting a proxy will not prevent you from voting in person, but it will help to secure a quorum, avoid added solicitation costs and protect the health and safety of our employees, advisors and other stockholders. Information on how to submit a proxy to vote your shares in advance of the Annual Meeting is discussed below.

How to Vote

Stockholder of Record. If you are a stockholder of record of common stock, you can vote your shares in one of two ways: either by proxy or in person at the Annual Meeting. If you choose to vote by proxy, you may do so via the Internet, by telephone or by mail. Each of these methods is explained below.

• By Internet. You may transmit your proxy voting instructions via the Internet by following the instructions provided on the Notice or the proxy card. You will need to have the control number that is on the Notice or the proxy card when voting. If you choose to vote via the Internet, you do not have to return the proxy card.
• By Telephone. If you request printed copies of the proxy materials by mail and you live in the United States or Canada, you may vote by proxy by calling the toll-free number found on the proxy card. You must have the control number that is on the Notice or the proxy card when voting. If you choose to vote by telephone, you do not have to return the proxy card.
• By Mail. If you request printed copies of the proxy materials by mail, you may vote by proxy by completing, signing and dating the proxy card and returning it in the envelope provided.
• In Person at the Annual Meeting. You may vote in person at the Annual Meeting. We will give you a ballot when you arrive. Even if you plan to attend the Annual Meeting, we urge you to vote your

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shares by proxy in advance of the Annual Meeting so that, if you should become unable to attend the Annual Meeting, your shares will be voted as directed by you.

Internet and telephone voting for stockholders of record that hold common stock will be available up until 11:59 p.m. Eastern Time on June 4, 2024, and mailed proxy cards must be received by June 4, 2024, in order to be counted at the Annual Meeting. If the Annual Meeting is continued, adjourned or postponed, these deadlines may be extended.

Beneficial Owner of Shares Held in Street Name. If your shares are held in street name (held for your account by a broker, bank, trust or other nominee or custodian), you can vote your shares as follows:

• By Internet or Telephone. You will receive instructions or a voting instruction form from the organization that holds your shares if you are permitted to vote by Internet or telephone.
• By Mail. You will receive instructions from the organization that holds your shares explaining how to vote your shares by mail.
• In Person at the Annual Meeting. If you attend the Annual Meeting, you may vote in person. To do so, you will need to show a picture identification as well as an account statement or a letter from the record holder indicating that you owned the shares as of the record date, and also obtain a legal proxy or broker's proxy card from the organization that holds your shares and bring it with you to the Annual Meeting.

The voting deadlines and availability of Internet and telephone voting for beneficial owners of shares held in "street name" will depend on the voting processes of the organization that holds your shares. Therefore, we urge you to carefully review and follow the instructions that you receive from that organization.

If you hold shares of our common stock in multiple accounts, you should vote your shares as described in each set of proxy materials that you receive.

Quorum

A quorum of stockholders is necessary to hold a valid meeting. Our bylaws provide that a quorum will exist if stockholders holding a majority of the shares of stock issued and outstanding and entitled to vote are present at the Annual Meeting in person or by proxy. Abstentions and broker non-votes count as present for establishing a quorum but will not be counted as votes cast. Broker non-votes occur when your broker or other nominee submits a proxy for your shares but has not received voting instructions from you and does not indicate a vote for a particular proposal because the broker or other nominee does not have the authority to vote on that proposal. If a quorum is not present, the Annual Meeting may be adjourned until a quorum is obtained.

Ballot Measures Considered "Discretionary" and "Non-Discretionary"

The election of directors (Proposal No. 1) is considered non-discretionary under applicable rules. A broker or other nominee cannot vote without instructions on non-discretionary matters, and therefore there may be broker non-votes on Proposal No. 1.

The approval of the Second Amended and Restated 2015 Plan (Proposal No. 2) is considered non- discretionary under applicable rules. A broker or other nominee cannot vote without instructions on non- discretionary matters, and therefore there may be broker non-votes on Proposal No. 2.

The ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2024 (Proposal No. 3) is considered discretionary under applicable rules. A broker or other nominee may generally exercise discretionary authority and vote on discretionary matters. If they exercise this discretionary authority, no broker non-votes are expected to exist in connection with Proposal No. 3.

The advisory vote on executive compensation (Proposal No. 4) is considered non-discretionary under applicable rules. A broker or other nominee cannot vote without instructions on non-discretionary matters, and therefore there may be broker non-votes on Proposal No. 4.

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Votes Required for Each Proposal

Directors are elected by a plurality of the votes cast by stockholders entitled to vote at the Annual Meeting (Proposal No. 1). This means that the three nominees receiving the most votes "for" will be elected. Shares represented by proxies that withhold authority to vote for a nominee for election as a director will not be counted as votes "for" a director. Votes that are withheld and broker non-votes, if any, will be counted for purposes of establishing a quorum and, if a quorum is present, we expect that votes that are withheld and broker non-votes will have no effect on the outcome of this proposal.

The approval of the Second Amended and Restated 2015 Plan requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voted "for" or "against" such matter (Proposal No. 2). Abstentions and broker non-votes, if any, will be counted for purposes of establishing a quorum and, if a quorum is present, we expect that abstentions and broker non-votes will have no effect on the outcome of the vote on this proposal.

The ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voted "for" or "against" such matter (Proposal No. 3). Abstentions and broker non- votes, if any, will be counted for purposes of establishing a quorum and, if a quorum is present, we expect that abstentions and broker non-votes will have no effect on the outcome of the vote on this proposal.

The approval, by non-binding advisory vote, of our executive compensation requires the affirmative vote of a majority of the shares of common stock present or represented by proxy and voted "for" or "against" such matter (Proposal No. 4). Abstentions and broker non-votes, if any, will be counted for purposes of establishing a quorum and, if a quorum is present, we expect that abstentions and broker non-votes will have no effect on the outcome of the vote on this proposal.

Method of Counting Votes

Each holder of common stock is entitled to one vote at the Annual Meeting on each matter to come before the Annual Meeting for each share held by such stockholder as of the record date. Votes cast in person at the Annual Meeting or by proxy via the Internet or by telephone or mail will be tabulated by the inspector of election appointed for the Annual Meeting, who will also determine whether a quorum is present.

Revoking a Proxy; Changing Your Vote

If you are a stockholder of record that holds common stock, you may revoke your proxy before the vote is taken at the Annual Meeting:

• by submitting a new proxy with a later date before the applicable deadline either signed and returned by mail or transmitted using the Internet or telephone voting procedures described in the "How to Vote" section above;
• by voting in person at the Annual Meeting; or
• by filing a written revocation with our corporate secretary.

If your shares are held in "street name," you may submit new voting instructions by contacting the organization that holds your shares. You may also vote in person at the Annual Meeting, which will have the effect of revoking any previously submitted voting instructions, if you obtain a legal proxy or broker's proxy card from the organization that holds your shares as described in the "How to Vote" section above.

Your attendance at the Annual Meeting will not automatically revoke your proxy.

Costs of Proxy Solicitation

We will bear the costs of soliciting proxies. In addition to solicitations by mail, our directors, officers and employees, without additional remuneration, may solicit proxies by telephone, facsimile, email, personal interviews and other means. In addition, we have engaged Alliance Advisors, LLC to assist in the solicitation of proxies and provide related advice and information support for a services fee and the reimbursement of customary disbursements, which are not expected to exceed $35,000 in total.

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Voting Results

We plan to announce preliminary voting results at the Annual Meeting and to publish final results in a Current Report on Form 8-K to be filed with the SEC within four business days following the Annual Meeting.

Appraisal Rights

Our stockholders are not entitled to dissenters' or appraisal rights under the General Corporation Law of the State of Delaware with respect to any of the proposals being voted on at the Annual Meeting.

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PROPOSAL NO. 1 - ELECTION OF CLASS III DIRECTORS

Our Board of Directors is divided into three classes, with one class of our directors standing for election each year, for a three-year term. The authorized size of our Board of Directors is currently nine. Directors for each class are elected at the annual meeting of stockholders held in the year in which the term for their class expires and hold office until their resignation or removal or their successors are duly elected and qualified. In accordance with our certificate of incorporation and bylaws, our directors may fill existing vacancies on our Board of Directors by appointment. The members of the classes are as follows:

• the Class I Directors are Fred Callori, Michael Kishbauch, and Jill C. Milne and their term will expire at the annual meeting of stockholders to be held in 2025;
• the Class II Directors are Kenneth Bate, Joanne Beck, and Hugh Cole, and their term will expire at the annual meeting of stockholders to be held in 2026; and
• the Class III Directors are Sunil Agarwal, Gregg Lapointe, and Jonathan Violin, and their term will expire at the Annual Meeting.

Our bylaws require that each of the classes of our Board of Directors consist, as nearly as may be possible, of one-third of the total number of directors constituting our entire Board of Directors. Our Board of Directors, on the recommendation of our nominating and corporate governance committee, has nominated Sunil Agarwal, Gregg Lapointe, and Jonathan Violin for re-election as Class III Directors at the Annual Meeting. Each Class III Director that is elected at the Annual Meeting will be elected to serve for a three-year term that will expire at our annual meeting of stockholders to be held in 2027.

If no contrary indication is made, proxies will be voted for Sunil Agarwal, Gregg Lapointe, and Jonathan Violin, or, in the event that any of these nominees is not a candidate or is unable to serve as a director at the time of election (which is not currently expected), for any substitute nominee who is designated by our Board of Directors.

Information Regarding Directors

The information set forth below as to the directors and nominees for director has been furnished to us by the directors and nominees for director:

Nominees for Election to our Board of Directors

For a Three-Year Term Expiring at the

2027 Annual Meeting of Stockholders (Class III)

Name	Age	Present Position with Astria Therapeutics, Inc.
Sunil Agarwal, M.D.		54		Director
Gregg Lapointe	65		Director
Jonathan Violin, Ph.D.	48		Director

Sunil Agarwal, M.D., has served as a member of our Board of Directors since April 8, 2024. Dr. Agarwal served as Executive Vice President and Chief Development Officer for Sana Biotechnology, Inc, a company focused on creating and delivering engineered cells as medicine for patients, from July 2018 to May 2023.

Prior to that, Dr. Agarwal served as President of Research and Development at Juno Therapeutics, Inc., a biopharmaceutical company, from April 2017 to May 2018. Prior to Juno, Dr. Agarwal served in various leadership and executive roles in the biopharmaceutical industry, including as a partner at Sofinnova Ventures, Chief Medical Officer and Senior Vice President of Ultragenyx Pharmaceutical Inc., a biopharmaceutical company, various leadership capacities at Genentech, Inc. (acquired by Roche Holdings, Inc.), including Senior Vice President and Global Head of Clinical Development for OMNI (Ophthalmology, Metabolism, Neurosciences, Immunology and Infectious Diseases), Senior Vice President for Immunology and Infectious Diseases, Vice President for Rheumatology, and Vice President of Genentech Drug Safety. Dr. Agarwal currently serves on the board of directors of Arvinas, Inc., a pharmaceutical company, and previously sat on the board of directors for Calithera Biosciences, Inc., a biopharmaceutical company, from 2015 to 2023, and MyoKardia, Inc. (acquired by Bristol Myers Squibb), a biopharmaceutical company, from 2016 to 2020. Dr. Agarwal obtained his B.S. in Neuro-Biology at Cornell University and then earned

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