Preliminary Proxy—Subject To Completion

601611 Gateway Boulevard, Suite 1250273

South San Francisco, California

94080

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To Be Held On May 24, 2023Wednesday, June 5, 2024

You are cordially invited to attend the 20232024 Annual Meeting of Stockholders or the Annual Meeting,(the “Annual Meeting”), of Quince Therapeutics, Inc. (the “Company”), or the Company, on Wednesday, May 24, 2023June 5, 2024 at 11:10:00 a.m. Pacific Time. The Annual Meeting will be a completely virtual meeting, conducted via live webcast on the internet at https://web.lumiagm.com/294872708.web.lumiconnect.com/294872708. There will be no physical location for the Annual Meeting. You will be able to attend and participate in the Annual Meeting online, submit questions during the meeting and vote your shares electronically. In addition, although the live webcast is available only to stockholders at the time of the meeting, following completion of the Annual Meeting, a webcast replay will be posted to the Investor Relations section of our website at https://ir.quincetx.com.ir.quincetx.com.

The matters expected to be acted upon at the Annual Meeting are described in the Proxy Statement accompanying this Notice of Annual Meeting of Stockholders and proxy statement.Stockholders. The Annual Meeting materials include this notice, the notice,Notice of Internet Availability of Proxy Materials, the proxy statement, our annual report and the proxy card, each of which is available at https:http://www.astproxyportal.com/ast/22818.22818.

Please use this opportunity to take part in our affairs by voting on the business to come before the Annual Meeting. You will receive a Notice of Internet Availability of Proxy Materials or the Notice,(the “Notice”), which we expect to mail on or about Wednesday, April 14, 2023,24, 2024, unless you have previously requested to receive our proxy materials in paper form. Only stockholders of record at the close of business on Thursday, April 3, 202318, 2024 may vote at the Annual Meeting and any postponements or adjournments of the meeting. All stockholders are cordially invited to participate in the Annual Meeting and any postponements or adjournments of the meeting. However, to ensure your representation at the Annual Meeting, please vote as soon as possible by using the internet or telephone, as instructed in the Notice. Alternatively, you may follow the procedures outlined in the Notice to request a paper proxy card to submit your vote by mail. Returning the paper proxy card or voting electronically does NOT deprive you of your right to participate in the virtual meeting and to vote your shares for the matters acted upon at the meeting.

Your vote is important. Whether or not you expect to attend and participate in the Annual Meeting, please submit your proxy electronically via the internet or by telephone by following the instructions in the Notice or if you asked to receive the proxy materials in paper form, please complete, sign and date the proxy card and return it in the postage paid envelope provided.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING TO BE HELD ON May 24, 2023:JUNE 5, 2024: THE PROXY STATEMENT, PROXY CARD AND ANNUAL REPORT ON FORM 10-K FOR THE FISCAL YEAR ENDED DECEMBER 31, 20222023 ARE AVAILABLE FREE OF CHARGE AT HTTPS:HTTP://WWW.ASTPROXYPORTAL.COM/AST/22818.22818.

Preliminary Proxy—Subject To Completion

QUINCE THERAPEUTICS, INC.

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

By Order of the Board of Directors,

TABLE OF CONTENTS

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Preliminary Proxy—Subject To Completion

QUINCE THERAPEUTICS, INC.

PROXY STATEMENT FOR THE 20232024 ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON WEDNESDAY, MAY 24, 2023JUNE 5, 2024

INFORMATION ABOUT SOLICITATION AND VOTING

The accompanying proxy is solicited on behalf of our board of directors of Quince Therapeutics, Inc., (the “Company” or Quince,“Quince”), for use at Quince’s 20232024 Annual Meeting of Stockholders (the “Annual Meeting” or the Annual Meeting or the meeting,“meeting”), to be held on Wednesday, May 24, 2023June 5, 2024 at 11:10:00 a.m. Pacific Time via live webcast on the internet at https://web.lumiagm.com/294872708.web.lumiconnect.com/294872708. References in the Proxy Statement to “we,” “us,” “our,” “the Company” or “Quince” refer to Quince Therapeutics, Inc.

INTERNET AVAILABILITY OF PROXY MATERIALS

We will mail, on or about Wednesday, April 14, 2023,24, 2024, the Notice of Internet Availability of Proxy Materials or the Notice,(the “Notice”), to our stockholders of record and beneficial owners at the close of business on Thursday, April 3, 2023.18, 2024 (the “Record Date”). On the date of mailing of the Notice, all stockholders and beneficial owners will have the ability to access all of the proxy materials on a website referred to in the Notice. These proxy materials will be available free of charge.

The Notice will identify the website where the proxy materials will be made available; the date, the time and location of the Annual Meeting; the matters to be acted upon at the meeting and our board of directors’ recommendations with regard to each matter; a toll-free telephone number, an e-mail address, and a website where stockholders can request a paper or e-mail copy of the Proxy Statement; our Annual Report on Form 10-K for the year ended December 31, 2022, or our Annual Report,2023 (our “Annual Report”), and a form of proxy relating to the Annual Meeting; information on how to access the form of proxy; and information on how to participate in the meeting and vote in person online.

QUESTIONS AND ANSWERS ABOUT THE MEETING

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Stockholder of Record: Shares Registered in Your Name

If your shares are registered directly in your name with our transfer agent, American Stock Transfer &Equiniti Trust Company, LLC, you are considered the stockholder of record with respect to those shares, and the Notice or these proxy materials were sent directly to you by Quince.

Beneficial Owner of Shares Held in Street Name: Shares Registered in the Name of a Broker or Nominee

If your shares are held in an account at a brokerage firm, bank, broker-dealer, or other similar organization, then you are the “beneficial owner” of shares held in “street name,” and the Notice or these proxy materials were forwarded 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 a beneficial owner, you have the right to instruct that organization on how to vote the shares held in your account. Because you are not the stockholder of record, you may not vote your shares at the Annual Meeting unless you request and obtain a valid proxy from the organization that holds your shares giving you the right to vote the shares at the Annual Meeting. Beneficial owners must obtain a valid proxy from the organization that holds their shares and present it to American Stock Transfer &Equiniti Trust Company, LLC at least two (2) weeks in advance of the Annual Meeting.

Stockholder of Record: Shares Registered in Your Name

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Votes submitted by telephone or through the internet must be received by 11:59 p.m. Eastern Time, on May 23, 2023.Tuesday, June 4, 2024. Submitting your proxy, whether by telephone, through the internet or by mail if you request or received a paper proxy card, will not affect your right to vote in person should you decide to attend and participate in the meeting virtually.

Beneficial Owner: Shares Registered in the Name of a Broker or Other Nominee

If you are not the stockholder of record, please refer to the voting instructions provided by your nominee to direct it how to vote your shares. Your vote is important. To ensure that your vote is counted, complete and mail the voting instruction card provided by your brokerage firm, bank, or other nominee as directed by your nominee. To electronically vote in person at the meeting online, you must obtain a legal proxy from your nominee. Follow the instructions from your nominee included with our proxy materials or contact your nominee to request a proxy form.

Your vote is important. Whether or not you plan to participate in the Annual Meeting, we urge you to vote by proxy to ensure that your vote is counted.

The telephone and internet voting procedures are designed to authenticate stockholders’ identities, to allow stockholders to give their voting instructions and to confirm that stockholders’ instructions have been recorded properly.

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As a reminder, if you are a beneficial owner of shares held in street name, in order to ensure your shares are voted in the way you would prefer, you must provide voting instructions to your broker, bank or other agent by the deadline provided in the materials you receive from your broker, bank or other agent.

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Please note, however, that if your shares are held of record by a broker, bank or other nominee and you wish to revoke a proxy, you must contact that firm to revoke any prior voting instructions.

The meeting webcast will begin promptly at 11:10:00 a.m.,am, Pacific Time. We encourage you to access the meeting prior to the start time. Online check-in will begin at 10:9:30 a.m., Pacific Time, and you should allow ample time for the check-in procedures. We plan to have a webcast replay which will be posted to the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations.

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If you choose to receive future proxy materials by email, you will receive an email next year with instructions containing a link to those materials and a link to the proxy voting site. Your election to receive proxy materials by email will remain in effect until you terminate it.

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addition, stockholder proposals must comply with the requirements of Rule 14a-8 under the Securities Exchange Act of 1934, as amended or the Exchange Act,(the “Exchange Act”), and related SEC regulations under Rule 14a-8 regarding the inclusion of stockholder proposals in company-sponsored proxy materials. In order to be included in the proxy statement for our 2024 Annual Meeting,2025 annual meeting of stockholders, stockholder proposals must be received by our Secretary no later than December 16, 202325, 2024 and must otherwise comply with the requirements of Rule 14a-8 of the Exchange Act.

Our amended and restated bylawsBylaws provide that stockholders may present proposals to be considered at an annual meeting by providing timely notice to our Secretary at our principal executive office. To be timely for our 2024 Annual Meeting,2025 annual meeting of stockholders, our Secretary must receive the written notice at our principal executive office:

If we hold our 20242025 annual meeting of stockholders more than 30 days before or more than 60 days after May 24, 2024June 5, 2025 (the one-year anniversary date of the Annual Meeting), then notice of a stockholder proposal that is not intended to be included in our proxy statement must be received by our Secretary at our principal executive office:

In addition, stockholders who intend to solicit proxies in support of director nominees other than Quince’s nominees must also comply with the additional requirements of Rule 14a-19(b).A stockholder’s notice to the Secretary must set forth as to each matter the stockholder proposes to bring before the annual meeting the information required by our amended and restated bylaws.Bylaws. If a stockholder who has notified Quince of such stockholder’s intention to present a proposal at an annual meeting does not appear to present such stockholder’s proposal at such meeting, Quince does not need to present the proposal for vote at such meeting. In addition to satisfying the deadlines in the “advance notice” provisions of our Bylaws, a stockholder who intends to solicit proxies in support of nominees submitted under these “advance notice” provisions, to comply with the universal proxy rules, stockholders who intend to solicit proxies in support of director nominees other than Quince’s nominees must include in their notice the information required by Rule 14a-19 under the Exchange Act.

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BOARD OF DIRECTORS AND CORPORATE GOVERNANCE

We have a strong commitment to good corporate governance practices. These practices provide an important framework within which our board of directors, its committees and our management can pursue our strategic objectives in order to promote the interests of our stockholders.

Corporate Governance Guidelines

Our board of directors has adopted Corporate Governance Guidelines that set forth expectations for directors, director independence standards, board committee structure and functions and other policies for the governance of our company. Our Corporate Governance Guidelines are available without charge on the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations,, by clicking on “Governance Documents” in the “Governance” section of our website. Our Corporate Governance Guidelines are subject to modification from time to time by our board of directors pursuant to the recommendations of our nominating and corporate governance committee.

Classified Board

At this time, our board of directors believes that the classified board structure is in the best interests of the Company and its stockholders. The classified board structure and corresponding three-year terms are intended to ensure that our directors have sufficient institutional knowledge of our business, corporate strategy and corporate objectives while also allowing for corporate continuity and stability of the board of directors, promoting the balance of long-term and short-term interests of the Company and its stockholders. Our board of directors believes a three-year term in office also allows our directors to stay focused on long-term value creation. Further, our board of directors believes that a classified board structure enables us to attract and retain diverse and highly qualified individuals willing to commit the time and dedication necessary to understand our business, its operations and its competitive environment. For example, a substantial amount of diversity on our Board is represented by directors who have joined our board of directors in the last three years. The structure also safeguards us from third-party takeover attempts, as it will require a longer period to change majority control of the board of directors.

Director Nomination Arrangements

Dr. Benatti was added to our board of directors pursuant to the agreement governing our acquisition of EryDel S.p.A. (“EryDel” and such acquisition, the “EryDel Acquisition”) in October 2023. The Stock Purchase Agreement (the “Purchase Agreement”), dated July 21, 2023 by and among the Company, EryDel Italy, Inc., EryDel, certain holders and the managers set forth on Schedule II thereto, and Shareholder Representative Services LLC, as the stockholder representative, provided that in connection with the EryDel Acquisition, we would add Dr. Benatti to our board of directors. Accordingly, we added Dr. Benatti to our board of directors effective at the closing of the EryDel Acquisition on October 20, 2023.

Dr. Thye was added to our board of directors pursuant to the agreement governing our acquisition of Novosteo Inc. (“Novosteo” and such acquisition, the “Novosteo Merger”) in May 2022. The Agreement and Plan of Merger and Reorganization (the “Merger Agreement”), dated May 9, 2022, by and among the Company, Novosteo, Quince Merger Sub I, Inc., Quince Merger Sub II, LLC, and Fortis Advisors LLC, solely in its capacity as the representative of the Participating Securityholders (as defined in the Merger Agreement), provided that in connection with the Novosteo Merger, we would add Dr. Thye to our board of directors. Accordingly, we added Dr. Thye to our board of directors effective at the closing of the Novosteo Merger on May 29, 2022.

Board Leadership Structure

Our Corporate Governance Guidelines provide that our board of directors shall be free to choose its Chairperson in any way that it considers in the best interests of our company, and that our nominating and corporate governance committee periodically considers the leadership structure of our board of directors and makes such recommendations to our board of directors with respect thereto as appropriate. In addition, our Corporate Governance Guidelines provide that, when

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the positions of Chairperson and Chief Executive Officer are held by the same person, our board of directors will designate a Lead Independent Director. We established a Lead Independent Director role with broad authority and responsibility, as described further below. The independent members of the board of directors also meet in executive session without management, which provides the board of directors with the benefit of having the perspective of independent directors. The Lead Independent Director presides over these executive sessions.

Until January 2022, Casey C. Lynch wasDavid A. Lamond serves as the Chairperson of our board of directors and our President and Chief Executive Officer, or CEO. As President and Chief Executive Officer, Ms. Lynch was involved in our day-to-day operations and was in a position to elevate business issues for consideration by our board of directors. Our independent directors brought experience, oversight and expertise from outside of our company, while Ms. Lynch brought company-specific experience. At the time, our board of directors determined that the combined role of Chairperson and Chief Executive Officer with a Lead Independent Director provided the leadership structure that was appropriate for our Company’s circumstances.

In January 2022, Ms. Lynch departed from our Company and the positions of Chairperson and CEO are no longer held by the same person. Dirk Thye, M.D. currentlyUna Ryan, OBE, Ph.D. serves as our CEO and our board of directors appointed David A. Lamond as the Chairperson. Una Ryan continues to serve as the Lead Independent Director. We believe this newthe leadership structure reinforces the independence of our board of directors in its oversight of the business and affairs of our Company. In addition, we believe that having separate CEO, independent Chairperson and Lead Independent Director positions creates an environment that is more conducive to objective evaluation and oversight of management’s performance, increasing management accountability and improving the ability of our board of director to monitor whether management’s actions are in the best interests of our Company and its stockholders. Our board of directors believes that our Company and stockholders are best served by maintaining flexibility to determine whether and when the Chairperson and CEO positions should be separate or combined to provide the best leadership for our Company.

Lead Independent Director

Our board of directors appointed Una Ryan, OBE, Ph.D. to serve as our Lead Independent Director. The responsibilities of the Lead Independent Director include:

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committee assesses risks related to our corporate governance practices, the independence of our board of directors and monitors the effectiveness of our governance guidelines. Our compensation committee assesses and monitors whether our compensation policies and programs have the potential to encourage excessive risk-taking.

We believe this division of responsibilities is an effective approach for addressing the risks we currently face and that our board leadership structure supports this approach.

Independence of Directors

The Nasdaq listing rules generally require that a majority of the members of a listed company’s board of directors be independent. In addition, the listing rules generally require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent.

In addition, audit committee members must also satisfy the independence criteria set forth in Rule 10A-3 under the Securities Exchange Act of 1934, as amended or the Exchange Act.(the “Exchange Act”). In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in such member’s capacity as a member of the audit committee, the board of directors or any other board committee (i) accept, directly or indirectly, any consulting, advisory or other compensatory fee from the listed company or any of its subsidiaries or (ii) be an affiliated person of the listed company or any of its subsidiaries.

Our board of directors conducts an annual review of the independence of our directors. Our board of directors has determined that none of the non-management members of our board of directors has a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. For the year ended December 31, 2022,2023, each of the members of our board of directors, other than Casey Lynch, Christopher Lowe and Dirk Thye as a result of theirhis service as our Chief Executive Officer, or interim Chief Executive Officer, was

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Compensation Committee

Our compensation committee is currently composed of David A. Lamond, who is the chair of our compensation committee and Margaret A. McLoughlin, Ph.D. The composition of our compensation committee meets the requirements for independence under current Nasdaq listing standards and SEC rules and regulations. Each member of this committee is also a non-employee director, as defined pursuant to Rule 16b-3 promulgated under the Exchange Act. Our compensation committee, among other things:

The compensation committee may delegate its authority to a subcommittee of the compensation committee (consisting either of a subset of members of the committee or, after giving due consideration to whether the eligibility criteria described within the compensation committee charter with respect to committee members and whether such other board members satisfy such criteria, any members of the board of directors) except for its exclusive authority to determine the amount and form of compensation paid to the Chief Executive Officer.

Our compensation committee has a written charter approved by our board of directors. A copy of the charter is available on the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations, by clicking on “Governance Documents” in the “Governance” section of our website.

Compensation Committee Processes and Procedures

Typically, the compensation committee meets at least four times annually and with greater frequency if necessary. The agenda for each meeting is developed by the chair of the compensation committee. The compensation committee meets regularly in executive session. In addition, members of management and other employees as well as outside advisors or consultants are regularly invited by the compensation committee to make presentations, to provide financial or other background information or advice or to otherwise participate in compensation committee meetings. However, the compensation committee meets regularly without such members present, and in all cases members of management are not present during the portion of meetings at which their compensation or performance is discussed or determined. Under the charter of the compensation committee, the compensation committee has the authority to obtain, at our expense, advice and assistance from compensation consultants and internal and external legal, accounting or other advisors and other external resources that the compensation committee considers necessary or appropriate in the performance of its duties, including compensation consultants to assist in its evaluation of executive and director compensation. Under the charter, before selecting a compensation consultant, legal counsel or other adviser, the compensation committee must consider all factors related to the independence of such advisors, including those specified by the Nasdaq listing rules.

The compensation committee retained Compensia, Inc. (“Compensia”), as its independent compensation consultant. The compensation committee requested that Compensia assist in evaluating the efficacy of our existing compensation strategy and practices in supporting and reinforcing our long-term strategic goals and in refining our compensation strategy and in developing and implementing an executive compensation program to execute that strategy and to ensure that our compensation programs remain competitive in attracting and retaining talented executives. At the request of the compensation committee, Compensia also conducted individual interviews with members of the compensation committee and senior management to learn more about our business operations and strategy, key performance metrics and strategic goals, as well as the labor markets in which we compete.

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In addition, as part of its engagement, our compensation committee requested that Compensia develop a group of peer companies to use as a reference in making compensation decisions, evaluating current pay practices and considering different compensation programs and best practices. Following an active dialogue with Compensia, the compensation committee recommended that the board of directors approve the recommendations of Compensia.

Nominating and Corporate Governance Committee

Our nominating and corporate governance committee is currently composed of David A. Lamond, who is the chair of our nominating and corporate governance committee, Margaret A. McLoughlin, Ph.D. and Una Ryan, OBE, Ph.D. The composition of our nominating and corporate governance committee meets the requirements for independence under current Nasdaq listing standards and SEC rules and regulations. Our nominating and corporate governance committee, among other things:

Our nominating and corporate governance committee has a written charter approved by our board of directors. A copy of the charter is available on the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations, by clicking on “Governance Documents” in the “Governance” section of our website.

Board and Committee Meetings and Attendance

Our board of directors and its committees meet regularly throughout the year, and also hold special meetings and act by written consent from time to time. During 2023: (i) our board of directors met eight (8) times; (ii) our audit committee met four (4) times; (iii) our compensation committee met two (2) times; and (iv) our nominating and corporate governance committee met two (2) times.

During 2023, each member of our board of directors attended at least 75% of the aggregate of all meetings of our board of directors and of all meetings of committees of our board of directors on which such member served that were held during the period in which such director served.

Board Diversity

While we do not have a formal diversity policy in place, our nominating and corporate governance committee considers the diversity of the board of directors overall with respect to age, disability, gender identity or expression, ethnicity, military veteran status, national origin, race, religion, sexual orientation, and other backgrounds and experiences. Our nominating and corporate governance committee is committed to actively seeking out and will instruct any search firm it engages to identify, individuals who will contribute to the overall diversity of the board of directors to be included in the pool of candidates from which nominees to the board of directors are selected.

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The Board Diversity Matrix below provides the diversity statistics for our board of directors as of April 17, 2024. To see our Board Diversity Matrix as of April 3, 2023, please see the proxy statement filed with the SEC on April 14, 2023.

Board Attendance at Annual Meeting of Stockholders

Our policy is to invite and encourage each member of our board of directors to be present at our annual meetings of stockholders. All of the directors who were members of our Board at the time of the 2023 Annual Meeting attended the 2023 Annual Meeting.

Communication with Directors

Stockholders and interested parties who wish to communicate with our board of directors, non-management members of our board of directors as a group, a committee of our board of directors or a specific member of our board of directors (including our Chairperson or Lead Independent Director) may do so by letters addressed to our Secretary.

All communications are reviewed by the Secretary and provided to the members of our board of directors as appropriate. Unsolicited items, sales materials, abusive, threatening or otherwise inappropriate materials and other routine items and items unrelated to the duties and responsibilities of our board of directors will not be provided to directors.

The address for these communications is:

Quince Therapeutics, Inc.

611 Gateway Boulevard, Suite 273

South San Francisco, California 94080

Attn: Secretary

Code of Business Conduct and Ethics

We have adopted a Code of Business Conduct and Ethics that applies to all of the members of our board of directors, officers and employees. Our Code of Business Conduct and Ethics is posted on the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations, by clicking on “Governance Documents” in the “Governance” section of our website. We intend to satisfy the disclosure requirement under Item 5.05 of Form 8-K regarding amendment to, or waiver from, a provision of our Code of Business Conduct and Ethics by posting such information on our website at the location specified above.

Hedging and Pledging Policy

Under the terms of our insider trading policy, no directors, officers, employees, and consultants are prohibited from engaging in hedging or monetization transactions involving our securities, such as prepaid variable forward contracts, equity swaps, collars or exchange funds. In addition, our insider trading policy prohibits such persons from trading in publicly-traded options, such as puts and calls, and other derivative securities with respect to our securities (other than stock options and other compensatory equity awards issued by us), as well as pledging our securities as collateral for a loan.

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REPORT OF THE AUDIT COMMITTEE

The information contained in the following report of our audit committee is not considered to be “soliciting material,” “filed” or incorporated by reference in any past or future filing by us under the Exchange Act or the Securities Act unless and only to the extent that we specifically incorporate it by reference.

Our audit committee has reviewed and discussed with our management and BDO USA, LLP,P.C., our audited financial statements for the fiscal year ended December 31, 2022.2023. Our audit committee has also discussed with BDO USA, LLPP.C. the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board and the SEC.

Our audit committee has received and reviewed the written disclosures and the letter from BDO USA, LLPP.C. required by applicable requirements of the PCAOB regarding the independent accountant’s communications with our audit committee concerning independence, and has discussed with BDO USA, LLPP.C. its independence from us.

Based on the review and discussions referred to above, our audit committee recommended to our board of directors that the audited financial statements be included in our annual report on Form 10-K for the fiscal year ended December 31, 20222023 for filing with the SEC.

Submitted byCode of Business Conduct and Ethics

We have adopted a Code of Business Conduct and Ethics that applies to all of the Audit Committee

Christopher J. Senner, Chair

June Bray

Una Ryan, OBE, Ph.D.

Compensation Committee

Our compensation committee is currently composedmembers of David A. Lamond, who is the chair of our compensation committee and Margaret A. McLoughlin, Ph.D. The composition of our compensation committee meets the requirements for independence under current Nasdaq listing standards and SEC rules and regulations. Each member of this committee is also a non-employee director, as defined pursuant to Rule 16b-3 promulgated under the Exchange Act. Our compensation committee, among other things:

The compensation committee may delegate its authority to a subcommittee of the compensation committee (consisting either of a subset of members of the committee or, after giving due consideration to whether the eligibility criteria described within the compensation committee charter with respect to committee members and whether such other board members satisfy such criteria, any members of the board of directors) except for its exclusive authority to determine the amount and form of compensation paid to the Chief Executive Officer.

Our compensation committee has a written charter approved by our board of directors. A copy of the charterEthics is availableposted on the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations,, by clicking on “Governance Documents” in the “Governance” section of our website. We intend to satisfy the disclosure requirement under Item 5.05 of Form 8-K regarding amendment to, or waiver from, a provision of our Code of Business Conduct and Ethics by posting such information on our website at the location specified above.

Compensation Committee ProcessesHedging and ProceduresPledging Policy

Typically,Under the compensation committee meets at least four times annuallyterms of our insider trading policy, no directors, officers, employees, and consultants are prohibited from engaging in hedging or monetization transactions involving our securities, such as prepaid variable forward contracts, equity swaps, collars or exchange funds. In addition, our insider trading policy prohibits such persons from trading in publicly-traded options, such as puts and calls, and other derivative securities with greater frequency if necessary. The agendarespect to our securities (other than stock options and other compensatory equity awards issued by us), as well as pledging our securities as collateral for each meeting is developed by the chair of the compensation committee. The compensation committee meetsa loan.

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regularlyREPORT OF THE AUDIT COMMITTEE

The information contained in executive session. In addition, membersthe following report of our audit committee is not considered to be “soliciting material,” “filed” or incorporated by reference in any past or future filing by us under the Exchange Act or the Securities Act unless and only to the extent that we specifically incorporate it by reference.

Our audit committee has reviewed and discussed with our management and other employees as well as outside advisors or consultants are regularly invitedBDO USA, P.C., our audited financial statements for the fiscal year ended December 31, 2023. Our audit committee has also discussed with BDO USA, P.C. the matters required to be discussed by the compensation committee to make presentations, to provide financial or other background information or advice or to otherwise participate in compensation committee meetings. However, the compensation committee meets regularly without such members present, and in all cases members of management are not present during the portion of meetings at which their compensation or performance is discussed or determined. Under the charterapplicable requirements of the compensation committee,Public Company Accounting Oversight Board and the compensationSEC.

Our audit committee has received and reviewed the authority to obtain, at our expense, advicewritten disclosures and assistancethe letter from compensation consultants and internal and external legal, accounting or other advisors and other external resources that the compensation committee considers necessary or appropriate in the performance of its duties, including compensation consultants to assist in its evaluation of executive and director compensation. Under the charter, before selecting a compensation consultant, legal counsel or other adviser, the compensation committee must consider all factors related to the independence of such advisors, including those specifiedBDO USA, P.C. required by the Nasdaq listing rules.

The compensation committee retained Compensia, Inc., or Compensia, as its independent compensation consultant. The compensation committee requested that Compensia assist in evaluating the efficacy of our existing compensation strategy and practices in supporting and reinforcing our long-term strategic goals and in refining our compensation strategy and in developing and implementing an executive compensation program to execute that strategy and to ensure that our compensation programs remain competitive in attracting and retaining talented executives. At the requestapplicable requirements of the compensationPCAOB regarding the independent accountant’s communications with our audit committee Compensia also conducted individual interviewsconcerning independence, and has discussed with members ofBDO USA, P.C. its independence from us.

Based on the compensationreview and discussions referred to above, our audit committee and senior managementto learn more about our business operations and strategy, key performance metrics and strategic goals, as well as the labor markets in which we compete.

In addition, as part of its engagement, our compensation committee requested that Compensia develop a group of peer companies to use as a reference in making compensation decisions, evaluating current pay practices and considering different compensation programs and best practices. Following an active dialogue with Compensia, the compensation committee recommended that the board of directors approve the recommendations of Compensia.

Nominating and Corporate Governance Committee

Our nominating and corporate governance committee is currently composed of David A. Lamond, who is the chair of our nominating and corporate governance committee, Margaret A. McLoughlin, Ph.D. and Una Ryan, OBE, Ph.D. The composition of our nominating and corporate governance committee meets the requirements for independence under current Nasdaq listing standards and SEC rules and regulations. Our nominating and corporate governance committee, among other things:

Our nominating and corporate governance committee has a written charter approved by our board of directors. A copy of the charter is available on the Investor Relations section of our website, which is located at https://ir.quincetx.com/investor-relations, by clicking on “Governance Documents” in the “Governance” section of our website.

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REPORT OF THE AUDIT COMMITTEE

The information contained in the following report of our audit committee is not considered to be “soliciting material,” “filed” or incorporated by reference in any past or future filing by us under the Exchange Act or the Securities Act unless and only to the extent that we specifically incorporate it by reference.

Our audit committee has reviewed and discussed with our management and BDO USA, P.C., our audited financial statements for the fiscal year ended December 31, 2023. Our audit committee has also discussed with BDO USA, P.C. the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board and the SEC.

Our audit committee has received and reviewed the written disclosures and the letter from BDO USA, P.C. required by applicable requirements of the PCAOB regarding the independent accountant’s communications with our audit committee concerning independence, and has discussed with BDO USA, P.C. its independence from us.

Based on the review and discussions referred to above, our audit committee recommended to our board of directors that the audited financial statements be included in our annual report on Form 10-K for the fiscal year ended December 31, 2023 for filing with the SEC.

Submitted by the Audit Committee

Christopher J. Senner, Chair

June Bray

Una Ryan, OBE, Ph.D.

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NOMINATIONS PROCESS AND DIRECTOR QUALIFICATIONS

Nomination to the Board of Directors

Candidates for nomination to our board of directors are selected by our board of directors based on the recommendation of our nominating and corporate governance committee in accordance with its charter, our amended and restated certificate of incorporation (“Certificate of Incorporation”) and amended and restated bylaws,Bylaws, our Corporate Governance Guidelines and the criteria approved by our board of directors regarding director candidate qualifications. In recommending candidates for nomination, our nominating and corporate governance committee considers candidates recommended by directors, officers, employees, stockholders. The Committee has engaged and may engage in the future consultants or third-party search firms to assist in identifying and evaluating potential nominees. using the same criteria to evaluate all candidates.

Additional information regarding the process for properly submitting stockholder nominations for candidates for nomination to our board of directors is set forth under “Requirements“When are stockholder proposals due for Stockholder Proposals to be considered for inclusion in our proxy materials for our 2024 Annual Meeting” and “Requirements for Stockholder Proposals to be presented at our 2024 Annual Meeting.next year’s annual meeting?”

Director Qualifications

With the goal of developing a diverse, experienced and highly qualified board of directors, our nominating and corporate governance committee is responsible for developing and recommending to our board of directors the desired qualifications, expertise and characteristics of members of our board of directors, including any specific minimum qualifications that the committee believes must be met by a committee-recommended nominee for membership on our board of directors and any specific qualities or skills that the committee believes are necessary for one or more of the members of our board of directors to possess.

Because the identification, evaluation and selection of qualified directors is a complex and subjective process that requires consideration of many intangible factors, and will be significantly influenced by the particular needs of our board of directors from time to time, our board of directors has not adopted a specific set of minimum qualifications, qualities or skills that are necessary for a nominee to possess, other than those that are necessary to meet U.S. legal, regulatory and Nasdaq listing requirements and the provisions of our amendedCertificate of Incorporation and restated certificate of incorporation and amended and restated bylaws,Bylaws, our Corporate Governance Guidelines and the charters of the committees of our board of directors. When considering nominees, our nominating and corporate governance committee may take into consideration many factors including, among other things, a candidate’s independence, integrity, diversity, skills, financial and other expertise, breadth of experience, knowledge about our business or industry and ability to devote adequate time and effort to responsibilities of our board of directors in the context of its existing composition. Our board of directors does not have a formal policy with respect to diversity and inclusion; however, it affirms the value placed on diversity within our company. Through the nomination process, our nominating and corporate governance committee seeks to promote board membership that reflects a diversity of business experience, expertise, viewpoints, personal backgrounds and other characteristics that are expected to contribute to our board of directors’ overall effectiveness. Further, our board of directors is committed to actively seeking highly qualified women and individuals from minority groups to include in the pool from which new candidates are selected. The brief biographical description of each director set forth in “Proposal One: Election of Directors” below includes the primary individual experience, qualifications, attributes and skills of each of our directors that led to the conclusion that each director should serve as a member of our board of directors at this time.

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PROPOSAL ONE: ELECTION OF DIRECTORS

Our board of directors currently consists of sixeight directors and is divided into three classes, with staggered three-year terms, pursuant to our amended and restated certificateCertificate of incorporationIncorporation and our amended and restated bylaws.Bylaws. There are twothree directors in Class III whose term of office expires in 2023, Margaret2024, Dirk Thye, M.D., David A. McLoughlin, Ph.D.Lamond, and Una Ryan, OBE,Luca Benatti, Ph.D. who will stand for election at the Annual Meeting. At the recommendation of our nominating and corporate governance committee, our board of directors nominated each of Dr. McLoughlinThye, Mr. Lamond, and Dr. RyanBenatti for election at the Annual Meeting as a Class III director for a three-year term expiring at our 20262027 Annual Meeting of Stockholders or until such director’s successor is duly elected and qualified or until such director’s earlier death, resignation, disqualification or removal. EachAll three of the nominees is currently a directorare current directors, and, if elected, will be continuing their roles on our board of the Company who wasdirectors. Dr. Thye and Dr. Benatti have not been previously elected by our stockholders. As described above, Dr. Benatti’s candidacy was recommended by EryDel pursuant to the stockholders.Purchase Agreement.

Shares represented by proxies will be voted “FOR” the election of each of the twothree nominees named below, unless the proxy is marked to withhold authority to so vote. If any nominee for any reason is unable to serve or for good cause will not serve, the proxies may be voted for such substitute nominee as the proxy holder might determine. Each nominee has consented to being named in this Proxy Statement and to serve if elected. Proxies may not be voted for more than twothree directors. Stockholders may not cumulate votes for the election of directors.

Nominees to Our Board of Directorsfor Election for a Three-year Term Expiring at the 2027 Annual Meeting

The nominees and their ages, occupations and lengths of service on our board of directors as of April 3, 202317, 2024 are provided in the table below and in the additional biographical descriptions set forth in the text below the table.

MargaretDirk Thye, M.D. has served as our Chief Executive Officer and member of our board of directors since May 2022 and Chief Medical Officer since January 2024. Prior to joining Quince Therapeutics, Inc., he served as the Chief Executive Officer of Novosteo Inc. from September 2021 to May 2022. Previously, Dr. Thye was the Executive Chairman of Geom Therapeutics, Inc. from January 2016 to July 2020 and the Chief Executive Officer of Agenovir Corporation from September 2016 to January 2018. Dr. Thye holds a M.D. from the University of California, Los Angeles and a B.A. in Molecular Biology from the University of California, Berkeley. We believe that Dr. Thye’s extensive experience in the biotechnology industry as an executive officer, as well as his education in biotechnology qualifies him to serve as a director.

David A. McLoughlin, Ph.D.Lamond has served on our board of directors since December 2015. From January 2014 to April 2019, Dr. McLoughlinMr. Lamond has served as the president of En Pointe LLC, an Executive Director in World Wide Business Development, at Pfizer Inc. focusing on venture investments, and from June 2018 to April 2019, she was a Partner in Pfizer Ventures, a venture capital arm of Pfizer Inc. focused on companies working in areas aligned with the future directions of Pfizer Inc. Dr. McLoughlininvestment firm, since 2016. He served as a directorthe President, Chief Executive Officer and Chief Investment Officer of Lamond Capital Partners LLC from 2011 to 2016. He also serves on the board of directors of 4DApplied Molecular Therapeutics, Inc.Transport, a biotechnology company, EG 427, a biotechnology company, Inquis Medical, a medical device company and Windfall Data, an analytics company. He previously served on the board of Arrinex, a medical device company until March 2019, Dr. McLoughlin joined Pfizer Inc.its acquisition by Stryker Corporation in 2001 and prior to focusing on venture investments, had roles of increasing responsibility within Worldwide Business Development where she led transactions with multiple biotech companies, academic institutions and other large pharma companies. Prior to working at Pfizer Inc., Dr. McLoughlin served as a Director in Yale’s Office of Cooperative Research for two years. Dr. McLoughlin served in various positions at Mallinckrodt Medical from 1992 to 1999, holding positions in Discovery Research, followed by Technology Planning. Dr. McLoughlinFebruary 2019. Mr. Lamond holds a B.S.B.A. in ChemistryHistory from theDuke University of California, Irvine and a Ph.D. in ChemistryJ.D. from the University of California, Santa Barbara.Duke Law School. We believe that Dr. McLoughlinMr. Lamond is qualified to serve as a director because of herhis extensive experience in the biotechnology industrywith important ecosystem partners and herhis service on a number of boards which provides an important perspective on operations, finance and corporate governance matters, as well as her education in biotechnology.matters.

Una Ryan, OBE, Ph.D.Luca Benatti, Ph.D,. has served on our board of directors since January 2019.October 2023. Since February 2024, Dr. RyanBenatti has served as a Managing Director at Golden Seeds LLC since 2012, a Partner at Astia Angel since 2012, and a Limited Partner at Breakout Ventures since 2016. She was Chairman of The Bay Area BioEconomy Initiative from 2012 to 2015. Dr. Ryan served as the President and Chief Executive Officer at Waltham Technologies, Inc. from 2008 to 2010. SheTes Pharma S.r.L, a biotechnology company. Dr. Benatti has also served as the Chief Executive Officer President and Chief Operating Officera director of AVANT Immunotherapeutics Inc.EryDel S.p.A., a private biotechnology company focused on rare diseases

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since June 2012. Prior to joining EryDel S.p.A, from 1998 to 2008 (which then became known as Celldex, Inc). She also served as the President andtill May 2012, Dr. Benatti was Chief Executive Officer of Diagnostics for All, or DFA, from 2009Newron Pharmaceuticals S.p.A., a publicly traded biopharmaceutical company that Dr. Benatti co-founded. From 1985 to 20121998, Dr. Benatti held various research and as Directordevelopment positions at Pharmacia & Upjohn and its predecessor companies. Dr. Benatti has authored several scientific publications and holds a number of Health Sciences at Monsanto Corporation from 1989 to 1993.patents. Dr. RyanBenatti currently serves on the board of directors of RenovoRx, Inc. since 2013. She also serves on the board of directors of the following non-profit entities: Cambridge in America, the University of Bristol Foundation and the San

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Rajiv Patni, M.D., joined our board of directors in February 2024. Dr. Patni brings to the board nearly 25 years of global product development experience in a diverse set of therapeutic areas, including cardiology, diabetology, hepatology, neurology, and benign hematology. Most recently, he served as Chief Research and Development Officer at Reata Pharmaceuticals, a commercial-stage company recently acquired by Biogen. Previously, Dr. Patni also served as Chief Medical Officer at several successful public, small-cap, and commercial-stage biopharmaceutical companies – Global Blood Therapeutics, Portola Pharmaceuticals, and Adamas Pharmaceuticals. He joined these companies at an inflection point in their R&D growth trajectories and contributed to their acquisition by larger companies. Earlier in his career, Dr. Patni held roles of increasing responsibility at Pfizer, Roche, and Actelion. His proven track record in fostering successful team efforts at these companies contributed to the approval of 11 medicines from the U.S. Food and Drug Administration, European Medicines Agency, and other regulatory agencies. Recent approvals include medicines for several rare diseases, including pulmonary arterial hypertension, advanced Parkinson’s disease, sickle cell disease, and Friedrich’s ataxia. He received his M.D. from the Ichan School of Medicine at Mount Sinai in New York City as part of an accelerated B.S./M.D. program. He completed an internal medicine residency and adult cardiology fellowship at the Albert Einstein College of Medicine, also in New York City, where he continued as an attending physician-scientist before joining the biopharmaceutical industry. We believe that Dr. Patni’s professional experience from translational to registrational studies and regulatory agency negotiation in several rare diseases and extensive executive experience in the biotechnology industry qualify him to serve as a director.

Directors Continuing in Office Until the 2026 Annual Meeting

Margaret A. McLoughlin, Ph.D., has served on our board of directors since December 2015. From January 2014 to April 2019, Dr. McLoughlin served as an Executive Director in World Wide Business Development, at Pfizer Inc. focusing on venture investments, and from June 2018 to April 2019, she was a Partner in Pfizer Ventures, a venture capital arm of Pfizer Inc. focused on companies working in areas aligned with the future directions of Pfizer Inc. Dr. McLoughlin served as a director on the board of directors of 4D Molecular Therapeutics, System1 Biosciences and Adapsyn Biosciences. Dr. McLoughlin joined Pfizer Inc. in 2001 and prior to focusing on venture investments, had roles of increasing responsibility within Worldwide Business Development where she led transactions with multiple biotech companies, academic institutions and other large pharma companies. Prior to working at Pfizer Inc., Dr. McLoughlin served as a Director in Yale’s Office of Cooperative Research for two years. Dr. McLoughlin served in various positions at Mallinckrodt Medical from 1992 to 1999, holding positions in Discovery Research, followed by Technology Planning. Dr. McLoughlin holds a B.S. in Chemistry from the University of California, Irvine and a Ph.D. in Chemistry from the University of California, Santa Barbara. We believe that Dr. McLoughlin is qualified to serve as a director because of her extensive experience in the biotechnology industry and her service on a number of boards, which provides an important perspective on operations and corporate governance matters, as well as her education in biotechnology.

Una Ryan, OBE, Ph.D., has served on our board of directors since January 2019. Dr. Ryan has served as a Managing Director at Golden Seeds LLC since 2012, a Partner at Astia Angel since 2012, and a Limited Partner at Breakout Ventures since 2016. She was Chairman of The Bay Area BioEconomy Initiative from 2012 to 2015. Dr. Ryan served as the President and Chief Executive Officer at Waltham Technologies, Inc. from 2008 to 2010. She served as the Chief Executive Officer, President and Chief Operating Officer of AVANT Immunotherapeutics Inc. from 1998 to 2008 (which then became known as Celldex, Inc). She also served as the President and Chief Executive Officer of Diagnostics for All, or DFA, from 2009 to 2012 and as Director of Health Sciences at Monsanto Corporation from 1989 to 1993. Dr. Ryan serves on the board of directors of the following private companies: RenovoRx and Elemental Machines. She also serves on the board of directors of the following non-profit entities: Cambridge in America, the University of Bristol Foundation and the San Francisco Art Institute. Dr. Ryan previously served as a director on the board of directors for AVANT Immunotherapeutics, Inc, AMRIGlobal, Inc, BayBio, MassBio, BIO, or Biotechnology Innovation Organization, New England Healthcare Institute, Board of Associates of the Whitehead Institute and Strategy & Policy Council of the MIT Center for Biomedical Innovation. Dr. Ryan holds a B.S. in Zoology, Microbiology, Chemistry from Bristol University and a Ph.D. in Cellular and Molecular Biology from Cambridge University. Dr. Ryan was awarded the Order of the British Empire for services to biotechnology. We believe that Dr. Ryan is qualified to serve as a director because of her extensive experience in the biotechnology industry and her service on a number of boards of companies, which provides an important perspective on operations and corporate governance matters.

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There are no family relationships among our directors and executive officers.

OUR BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR BOTH”ALL” NOMINEES FOR THE ELECTION OF THE TWOTHREE CLASS III DIRECTORS SET FORTH IN THIS PROPOSAL ONE.

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PROPOSAL TWO: APPROVAL OF AMENDMENT TO OUR CERTIFICATE OF INCORPORATION TO EFFECT A REVERSE STOCK SPLIT OF THE ISSUED AND OUTSTANDING COMMON STOCK

Our Boardboard of directors has approved, and is recommending that our stockholders approve, a proposed amendment to our certificate of incorporation, to effect a reverse split of the issued and outstanding shares of the common stock at a ratio of one-for-ten or the Reverse (the “Reverse Stock Split.Split”). The form of proposed amendment to our certificate of incorporation to effect the Reverse Stock Split is attached as Appendix A to this proxy statement. The text of the proposed amendment is subject to revision to include such changes as may be required by the Secretary of State of the State of Delaware and as our Boardboard of directors deems necessary or advisable to effect the proposed amendment of the certificate of incorporation. If a certificate of amendment is filed with the Secretary of State of the State of Delaware, the certificate of amendment to the certificate of incorporation will affect the Reverse Stock Split by reducing the outstanding number of shares of the common stock by athe ratio to be determined by the board of one-for-ten,directors, but will not increase the par value of the common stock and will not change the number of authorized shares of the common stock. If the Boardboard of directors does not implement an approved Reverse Stock Split prior to the one-year anniversary of this meeting, the Boardboard of directors will seek stockholder approval before implementing any Reverse Stock Split after that time.

By approving Proposal Two and the Reverse Stock Split,this proposal, stockholders will approve the amendment to our certificate of incorporation pursuant to which any whole numberten shares of outstanding shares, between and including ten and twenty,common stock, would be combined into one share of common stock and authorize our Boardboard of directors to file one certificate of amendment, as determined by our Boardboard of directors in the manner described herein. If approved, our Boardboard of directors may also elect not to effect any Reverse Stock Split and consequently not file any certificate of amendment to the certificate of incorporation.

The Reverse Stock Split will take effect, if at all, only after it is (i) approved by the affirmative vote of a majority of the shares of outstanding common stock cast at the annual meeting and entitled to vote on the matter, (ii) is deemed by the board of directors to be in the best interests of the Company and its stockholders, and (iii) after filing the amendment to our Certificate of Incorporation with the Secretary of State of the State of Delaware. If the Certificate of Amendment is filed with the Secretary of State of the State of Delaware, the Certificate of Amendment will effect the Reverse Stock Split by reducing the outstanding number of shares of the Common Stock by the ratio to be determined by the board of directors, but will not increase the par value of the common stock, and will not change the number of authorized shares of the Common Stock. If the board of directors does not implement an approved Reverse Stock Split prior to the one-year anniversary of this meeting, the board of directors will seek stockholder approval before implementing any Reverse Stock Split after that time. You should keep in mind that the implementation of a reverse stock split does not have an effect on the intrinsic value of our business or your proportional ownership in it.

Nasdaq Listing Compliance

Our common stock is listed on the Nasdaq Global Select Market under the symbol “QNCX.” To maintain a listing on the Nasdaq Global Select Market, we must satisfy various listing maintenance standards established by Nasdaq. If we are unable to meet the Nasdaq Global Select Market requirements, our common stock will be subject to delisting.

Among other things, we are required to comply with the continued listing requirements of the Nasdaq Global Select Market, including that the common stock maintain a minimum bid price of $1.00 on the Nasdaq Global Select Market or the Minimum(the “Minimum Bid Price Requirement.Requirement”). We currently satisfy this Minimum Bid Price Requirement. Assuming our stockholders approve this proposal, our Board will determine whether to effect a Reverse Stock Split at a ratio of one-for-ten, to allow us to maintain the $1.00 minimum bid price requirement.

Reasons for the Reverse Stock Split

On December 13, 2022,4, 2023, Nasdaq notified us that the bid price of our common stock had closed below the required $1.00 per share for 30 consecutive trading days, and, accordingly, that we did not comply with the applicable Minimum Bid Price Requirement for continued listing on the Nasdaq Global Select Market. While we regained compliance with the Minimum Bid Price Requirement, our Boardboard of directors believes that the Reverse Stock Split would, among other things, betterwill result in a higher per share trading price, which is intended to enable us to maintain the listing of our common stock on Nasdaq.the Nasdaq Global Select Market and generate greater investor interest in the Company. If our common stock were delisted from the Nasdaq Global Select Market, the board of directors believes that such delisting would adversely affect the market liquidity of our common stock, decrease the market price of our common stock, adversely affect our ability to obtain

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financing for the continuation of our operations and result in the loss of confidence in our company. In the event that our stockholders fail to approve this proposal, the Company could be prevented in the future from complying with the Minimum Bid Price Requirement or other Nasdaq listing requirements.

Our Boardboard of directors has considered the potential harm to us of a delisting of the common stock and has determined that, if the common stock continues to trade below $1.00 per share, the consummation of the Reverse Stock Split is the best way to maintain liquidity by achieving compliance with the Minimum Bid Price Requirement. Our Boardboard of directors also believes that the current low per share market price of the common stock has a negative effect on the marketability of our existing shares. Our Boardboard of directors believes there are several reasons for this effect. First, certain institutional investors have internal policies preventing the purchase of low-priced stocks. Second, a variety of policies and practices of broker-dealers discourage individual brokers within those firms from dealing in low-priced stocks. Third, because the brokers’ commissions on low-priced stocks generally represent a higher percentage of the stock price than commissions on higher priced stocks, the current share price of the common stock can result in individual stockholders paying transaction costs (commissions, markups or markdowns) that are a higher percentage of their total share value than

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Our board of directors reserves the right to abandon the Reverse Stock Split without further action by our stockholders at any time before the effectiveness of our Certificate of Amendment, even if the Reverse Stock Split has been authorized by our stockholders. By voting in favor of the Reverse Stock Split, you are expressly authorizing our board of directors to determine not to proceed with, and abandon, the Reverse Stock Split if it should so decide.

Effects of the Reverse Stock Split

The Reverse Stock Split will be effected simultaneously for all issued and outstanding shares of common stock and the Reverse Stock Split ratio will be the same for all issued and outstanding shares of common stock. The Reverse Stock Split will affect all of our stockholders uniformly and will not affect any stockholder’s percentage ownership interests in Quince, except that stockholders who would have otherwise received fractional shares will receive cash in lieu of such fractional shares. After the Reverse Stock Split, each share of the common stock will have the same voting rights and rights to dividends and distributions and will be identical in all other respects to the common stock now authorized and common stock issued pursuant to the Reverse Stock Split will remain fully paid and non-assessable.

The Reverse Stock Split would reduce the number of shares of common stock available for issuance under our 2019 Equity Incentive Plan or the 2019 Plan,(the “2019 Plan”), our 2019 Employee Stock Purchase Plan or the ESPP,(the “ESPP”), our 2022 Inducement Plan, and the Novosteo 2019 Equity Incentive Plan (the “Novosteo Plan”), in proportion to the reverse split ratio of the Reverse Stock Split.

Similarly, under the terms of the 2019 Plan and the agreements governing the Company’s outstanding stock options, the Reverse Stock Split will effect a reduction in the number of shares of the Company’s common stock issuable upon the vesting of such stock options in proportion to the reverse split ratio of the Reverse Stock Split. In connection with the Reverse Stock Split, the number of shares of the Company’s common stock issuable upon the vesting of outstanding stock options will be rounded down to the nearest whole share, and no cash payment will be made in respect of such rounding.

The Reverse Stock Split is not intended as, and will not have the effect of, a “going private transaction” covered by Rule 13e-3 under the Securities Exchange Act of 1934, as amended.Act. We will continue to be subject to the periodic reporting requirements of the Securities Exchange Act of 1934, as amended.Act.

The number of shares of the common stock that would be outstanding immediately after the Reverse Stock Split at the exchange ratio of one-for-ten, based on the 36,278,433      shares of common stock outstanding as of April 3, 2023the Record Date is      3,627,843.. This estimate does not account for fractional shares that will be paid in cash.

If a stockholder owns 10,000 shares of common stock prior to the Reverse Stock Split, after the Reverse Stock Split that same stockholder would own 1,000 shares afterin the case of a Reverse Stock Split at athe ratio of one-for-ten.

Accounting Matters

The Reverse Stock Split will not affect the par value of the common stock. As a result, upon the effectiveness of the Reverse Stock Split, the stated capital on our balance sheet attributable to the common stock will be reduced

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product obtained by multiplying (i) the closing sales price of the common stock as reported on the Nasdaq Global Select Market on the effective date of the certificate of amendment to the Certificate of Incorporation by (ii) the number of shares of common stock held by such stockholder before the Reverse Stock Split that would otherwise have been exchanged for such fractional share interest. Holders of as many as 9 shares (if we were to implement the one-for-ten Reverse Stock Split) of common stock would be eliminated as a result of the cash payment in lieu of any issuance of fractional shares or interests in connection with the Reverse Stock Split. The exact number by which the number of holders of the common stock would be reduced will depend on the number of stockholders that hold less than 10 shares as of the effective date of the Reverse Stock Split. As of the Record Date, there were approximately 61 holders of record of the common stock, of which one       was a holder of fewer than 10 shares of common stock. As a result of the Reverse Stock Split, assuming a Reverse Stock Split ratio of one-for-ten, we estimate that cashing out fractional stockholders would potentially reduce that number of stockholders of record to      60..

Stockholders should be aware that, under the escheat laws of the various jurisdictions where stockholders reside, where we are domiciled and where the funds will be deposited, sums due for fractional interests that are not timely claimed after the effective time may be required to be paid to the designated agent for each such jurisdiction. Thereafter, stockholders otherwise entitled to receive such funds may have to seek to obtain them directly from the state to which they were paid.

Certain Risks Associated with the Reverse Stock Split

Before voting on this Proposal Two, stockholders should consider the following risks associated with effecting a Reverse Stock Split:

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Potential Anti-Takeover Effect of the Reverse Stock Split

Upon effectiveness of the Reverse Stock Split, the number of authorized shares of common stock that are not issued or outstanding will increase relative to the number of shares of common stock that are issued and outstanding prior to the Reverse Stock Split. While this increase could, under certain circumstances, have an anti-takeover effect (for example, by permitting issuances that would dilute the stock ownership of a person seeking to effect a change in the composition of the Board or contemplating a tender offer or other transaction for the combination of Quince with another company), Proposal Two is not being proposed in response to any effort of which we are aware to accumulate shares of the common stock or to obtain control of Quince.

Effective Date

If our stockholders approve the Reverse Stock Split, the Reverse Stock Split would become effective at such time as it is deemed by our Boardboard of directors to be in the best interests of Quince and our stockholders and we file the amendment to our certificate of incorporation. Even if the Reverse Stock Split is approved by our stockholders, our Board has discretion not to carry out or to delay in carrying out the Reverse Stock Split. Upon the filing of the amendment, all of the pre-Reverse Stock Split shares will be converted into new common stock as set forth in the amendment.

Exchange of Stock Certificates

Some stockholders hold their shares of common stock in certificate form or a combination of certificate and book-entry form. Our transfer agent will act as the “exchange agent” for purposes of implementing the exchange of stock certificates. Stockholders holding pre-split shares that are certificated will be asked to surrender to the exchange agent certificates representing pre-split shares in exchange for certificates representing post-split shares in accordance with the procedures to be set forth in a letter of transmittal to be sent by the exchange agent. No new certificates will be issued to a stockholder until such stockholder has surrendered the stockholder’s outstanding certificate(s) together with the properly completed and executed letter of transmittal to the exchange agent. Stockholders whose shares are held in book-entry form or by their stockbroker do not need to submit old share certificates for exchange. These stockholders’ book-entry records or brokerage accounts will automatically reflect the new quantity of shares based on athe selected reverse stock split ratio of one-for-ten.ratio. As soon as practicable after the Effective Time, our transfer agent will send to such stockholders or their brokers a transmittal letter along with a statement of ownership indicating the number of post-reverse stock split shares of common stock held. Beginning on the effective date of the reverse stock split, each certificate or other share ownership record representing pre-split shares will be deemed for all corporate purposes to evidence ownership of post-split shares.

STOCKHOLDERS SHOULD NOT DESTROY ANY STOCK CERTIFICATE(S) AND SHOULD NOT SUBMIT ANY CERTIFICATE(S) UNTIL REQUESTED TO DO SO.

Certain Material U.S. Federal Income Tax Consequences of the Reverse Stock Split to U.S. Holder

The following is a summary of certain material U.S. federal income tax consequences of the Reverse Stock Split that generally are expected to be applicable to U.S. Holders (as defined below) of the common stock, but does not purport to be a complete discussion of all of the potential tax considerations relating thereto. This summary is based on the provisions of the U.S.United States federal income tax law (including the Internal Revenue Code of 1986, as amended or the Code,(the “Code”, applicable Treasury Regulations promulgated thereunder, and judicial authorities and current administrative rulings and practices as in effect on the date of this proxy statement). Changes to these laws could alter the tax consequences described below, possibly with retroactive effect, which may result in the U.S. federal income tax consequences of the Reverse Stock Split differing substantially from the consequences summarized below. We have not sought and will not seek an opinion of counsel or a ruling from the Internal Revenue Service regarding the U.S. federal income tax consequences of the Reverse Stock Split, and there can be no assurance that the Internal Revenue Service or the courts will accept the positions expressed below. This summary assumes that the common stock will be, both before and after the Reverse Stock Split, held as a “capital asset,” as defined in the Code (i.e., generally, property held for investment). Further, it does not discuss the tax consequences of the Reverse Stock Split under state, local, or

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foreign laws or under gift, excise or other non-income tax laws, or the application of the alternative minimum tax rules, the Medicare

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more than one year. Long-term capital gains of individuals are generally subject to tax at reduced rates. There are limitations on the deductibility of capital losses under the Code. A U.S. Holder’s aggregate tax basis in the reduced number of shares of common stock, if any, should equal the U.S. Holder’s aggregate tax basis in its pre-Reverse Stock Split shares of common stock decreased by the basis allocated to the fractional share for which such U.S. Holder is entitled to receive cash, and the holding period of the reduced number of shares of common stock received, if any, should include the holding period of the pre-Reverse Stock Split shares of common stock exchanged.

Information Reporting and Backup Withholding

A holder of common stock may be subject to information reporting and backup withholding on cash paid in lieu of fractional shares in connection with the Reverse Stock Split. To avoid backup withholding, each holder of common stock that does not otherwise establish an exemption should provide its taxpayer identification number and comply with the applicable certification procedures. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules generally will be allowed as a refund or credit against a U.S. Holder’s U.S. federal income tax liability, provided the required information is timely and properly furnished to the Internal Revenue Service. Holders of common stock should consult their tax advisors regarding their qualification for an exemption from backup withholding and the procedures for obtaining such an exemption, as well as the procedures for obtaining a credit or refund if backup withholding is imposed.

THE PRECEDING DISCUSSION IS INTENDED ONLY AS A SUMMARY OF CERTAIN MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES OF THE REVERSE STOCK SPLIT TO U.S. HOLDERS. IT IS NOT A COMPLETE ANALYSIS OR DISCUSSION OF ALL POTENTIAL TAX EFFECTS THAT MAY BE IMPORTANT TO A PARTICULAR HOLDER. ALL HOLDERS OF OUR COMMON STOCK SHOULD CONSULT THEIR OWN TAX ADVISORS AS TO THE SPECIFIC TAX CONSEQUENCES OF THE REVERSE STOCK SPLIT TO THEM, INCLUDING RECORD RETENTION AND TAX-REPORTING REQUIREMENTS, AND THE APPLICABILITY AND EFFECT OF ANY U.S. FEDERAL, STATE, LOCAL AND NON-U.S. TAX LAWS.

No Dissenters’ Rights

Under applicable Delaware law, our stockholders are not entitled to dissenters’ or appraisal rights with respect to our proposed amendment to the certificate of incorporation to effect the Reverse Stock Split. We will not independently provide our stockholders with any such right.

Vote Required

The affirmative vote of the holders of a majority of all outstanding shares of the common stock is required for approval of the proposed amendment to our amended and restated certificate of incorporation to effect a Reverse Stock Split set forth in this Proposal Two.

OUR BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” APPROVAL OF PROPOSAL TWO.

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PROPOSAL THREE: RATIFICATION OF SELECTION OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Our audit committee has selected BDO USA, LLPP.C. as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 20232024 and has further directed that management submit the selection of its independent registered public accounting firm for ratification by the stockholders at the annual meeting.Annual Meeting. BDO USA, LLPP.C. has audited the Company’s financial statements since 2018. Representatives of BDO USA, LLPP.C. are expected to be present at the Annual Meeting. They will have an opportunity to make a statement if they so desire and will be available to respond to appropriate questions.

Neither our Bylaws nor other governing documents or law require stockholder ratification of the selection of BDO USA, LLPP.C. as the Company’s independent registered public accounting firm. However, the audit committee is submitting the selection of BDO USA, LLPP.C. to the stockholders for ratification as a matter of good corporate practice. If the stockholders fail to ratify the selection, the audit committee will reconsider whether or not to retain that firm. Even if the selection is ratified, the audit committee in its discretion may direct the appointment of different independent auditors at any time during the year if they determine that such a change would be in the best interests of the Company and its stockholders.

Independent Registered Public Accounting Firm Fees and Services

The following table represents aggregate fees billed to the Company for the fiscal years ended December 31, 20222023 and December 31, 2021,2022, by BDO USA, LLC,P.C., the Company’s principal accountant:

All fees described above were pre-approved by our audit committee.

Policy on Audit Committee Pre-Approval of Audit and Permissible Non-Audit Services of Independent Registered Public Accounting Firm

Our audit committee’s policy is to pre-approve all audit and permissible non-audit services provided by our independent registered public accounting firm, the scope of services provided by our independent registered public accounting firm and the fees for the services to be performed. These services may include audit services, audit-related services, tax services and other services. Pre-approval is detailed as to the particular service or category of services and is generally subject to a specific budget. The Audit Committeeaudit committee or its Chair, whom the Audit Committeeaudit committee has designated as a one-person subcommittee with pre-approval authority, pre-approved all audit fees, audit-related fees, tax fees and other fees in 20222023 and 2021.2022. Any pre-approvals by the subcommittee must be and were presented to the Audit Committeeaudit

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committee at its next scheduled meeting. Our independent registered public accounting firm and management are required to periodically report to the audit committee regarding the extent of services provided by our independent registered public accounting firm in accordance with this pre-approval, and the fees for the services performed to date.

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PROPOSAL FOUR: ADVISORY VOTE ON THE COMPENSATION OF THE NAMED EXECUTIVE OFFICERS

Under the Dodd-Frank Wall Street Reform and Consumer Protection Act or the Dodd-Frank Act,(the “Dodd-Frank Act”), and Section 14A of the Exchange Act, the Company’s stockholders are entitled to vote to approve, on an advisory basis, the compensation of the Company’s named executive officers as disclosed in this Proxy Statement in accordance with SEC rules. This vote is not intended to address any specific item of compensation, but rather the overall compensation of our named executive officers and the philosophy, policies and practices described in this Proxy Statement.

The compensation of our named executive officers subject to the vote is disclosed in “Executive Compensation,” and the compensation tables and the related narrative disclosure contained in this Proxy Statement.

Accordingly, the Board recommends that our stockholders vote FOR the following resolution:

“RESOLVED, that the compensation paid to our named executive officers, as disclosed pursuant to Item 402 of Regulation S-K, including the compensation tables and narrative discussion, is hereby APPROVED.”

Because the vote is advisory, it is not binding on the Boardboard of directors or on us. Nevertheless, the views expressed by our stockholders, whether through this vote or otherwise, are important to management and the Boardboard of directors and, accordingly, the compensation committee and Boardboard of directors intend to consider the results of this vote in making determinations in the future regarding executive compensation arrangements. Your vote will serve as an additional tool to guide the compensation committee and Boardboard of directors in continuing to improve the alignment of our executive compensation programs with business objectives and performance and with the interests of our stockholders. Unless the Boardboard of directors decides to modify its policy regarding the frequency of soliciting say-on-pay votes, the next scheduled say-on-pay vote will be at the 20242025 Annual Meeting of Stockholders.

Vote Required

Advisory approval of Proposal Four requires the affirmative vote of a majority of the shares present in person online, by remote communication or represented by proxy and entitled to vote on the matter at the Annual Meeting.

OUR BOARD OF DIRECTORS RECOMMENDS A VOTE “FOR” APPROVAL OF PROPOSAL FOUR.

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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth certain information with respect to the beneficial ownership of our common stock as of March 31, 20232024 by:

Beneficial ownership is determined in accordance with the rules of the SEC and generally includes any shares over which a person exercises sole or shared voting or investment power. Unless otherwise indicated below, to our knowledge, the persons and entities named in the table have sole voting and sole investment power with respect to all shares beneficially owned by them, subject to community property laws where applicable. Shares of our common stock subject to stock options that are currently exercisable or exercisable within 60 days of March 31, 20232024 are deemed to be outstanding and to be beneficially owned by the person holding the stock options for the purpose of computing the percentage ownership of that person, but are not treated as outstanding for the purpose of computing the percentage ownership of any other person.

Percentage ownership of our common stock is based on 36,278,43343,215,233 shares of our common stock outstanding on March 31, 2023.2024. Unless otherwise indicated, the address of each of the individuals and entities named below is c/o Quince Therapeutics, Inc., 601611 Gateway Boulevard, Suite 1250,273, South San Francisco, California 94080.

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EXECUTIVE OFFICERS

OurThe following table sets forth certain information regarding our executive officers and their ages as of April 3, 2023 and positions with Quince are provided in the table below and in the additional biographical descriptions set forth in the text below the table.17, 2024.

Dirk Thye, M.D. For a brief biography of Dr. Thye, please see “Proposal One: Election of Directors—Continuing Directors.”Nominees to Our Board of Directors” above.

Karen Smith, M.D.,Charles Ryan, Ph.D., LLM, MBA, has served as our Chief Medical OfficerPresident since May 8, 2022. Dr. Smith currently serves on the board of directors of Sangamo Therapeutics, Inc. and Talaris Therapeutics, Inc. Dr. Smith served on the on the board of directors of Antares Pharma, Inc. until its acquisition by Halozyme Therapeutics, Inc. in April 2022. Prior to joining Quince Therapeutics, Inc., Dr. Smith served as the Chief Medical Officer of Novosteo Inc.September 2023. Most recently from SeptemberMay 2021 to May 2022. Previously, sheOctober 2022, Dr. Ryan served as President, and Chief Executive Officer, at Medeorand Chairman of Travecta Therapeutics, Inc., a biotechnologyprivate biopharmaceutical company from May 2019pioneering transformative treatments for serious neurological conditions. From December 2017 to JanuaryDecember 2020, andhe served as Chief Executive Officer and Director of Eliminate Cancer,Neurotrope, Inc. from June 2018, a clinical-stage biopharmaceutical company developing targeted, novel regenerative therapeutics for neurodegenerative diseases and developmental disorders. Prior to May 2019. Dr. Smith alsothat, he served as ExecutiveSenior Vice President of Global Head of Research and Development and Chief Medical Officer of Jazz Pharmaceuticals, Inc. from April 2015 to June 2018. SheIntellectual Property Counsel at Forest Laboratories (now AbbVie) for more than 10 years where he managed several intellectual property estates spanning CNS, cardiovascular, gastrointestinal, respiratory, and anti-infective therapeutic areas. He also worked closely with the commercial and development teams, as well as the business development teams at Forest. Dr. Ryan holds a M.D.J.D. from Western New England University, of Warwick, a Ph.D. in OncologyOral Biology and Pathology from Stony Brook University, of California, Los Angeles, an MBA from the University of New England and a LLMB.A. in Chemistry from The College of Wooster. He is a member of the UniversityNew York State Bar and is a patent practitioner of Salford.the U.S. Patent and Trademark Office.

Brendan Hannah has served as our Chief Business Officer since May 2022.2022 and was also appointed as our Chief Compliance Officer in March 2023 and our Chief Operating Officer in October 2023. Previously, Mr. Hannah served as the Chief Operating Officer of Novosteo Inc., a biopharmaceutical company, from November 2021 to May 2022. Previously, from January 2019 to October 2021, Mr. Hannah was the Chief Business Officer of Neuroptika, Inc., a biopharmaceutical company, and from January 2017 to March 2020, the Co-Founder and Vice President of Operations and Strategy of Geom Therapeutics, a biopharmaceutical company. Mr. Hannah was the Head of Corporate Development at Agenovir Corporation from January 2017 to January 2018. Mr. Hannah holds an MBA.M.B.A. from the University of California, Los Angeles Anderson School of Management and a B.A. in Economics from Colorado College.

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EXECUTIVE COMPENSATION

Our named executive officers (“NEOs”) for fiscal 20222023 consisted of the following individuals:

SUMMARY COMPENSATION TABLE

The following table sets forth all of the compensation awarded to, earned by, or paid to each of the NEOs for their services rendered for the years ended December 31, 20222023 and 2021.2022.

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