CRESCENT BIOPHARMA, INC.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Check the appropriate box:

CRESCENT BIOPHARMA, INC.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

NOTICE OF ANNUAL GENERAL MEETING OF SHAREHOLDERS

To Be Held on June 2, 2026

Dear Shareholder:

You are cordially invited to attend the Annual General Meeting of Shareholders of Crescent Biopharma, Inc., a Cayman Islands company incorporated and registered by way of continuation as an exempted company under the laws of the Cayman Islands (“we,” “us,” “our,” “Crescent” or the “Company”). The meeting will be held virtually on Tuesday, June 2, 2026 at 9:00 a.m. Eastern Time via live audio-only webcast atwww.virtualshareholdermeeting.com/CBIO2026. The meeting will be held online only. You will be able to vote your shares electronically over the Internet and submit questions online during the meeting by logging in to the website listed above using the 16-digit control number included in your Notice of Internet Availability of Proxy Materials, on your proxy card or on the instructions that accompanied your proxy materials. Online check-in will begin at 8:45 a.m. Eastern Time and you should allow ample time for the check-in procedures. You may submit questions before the meeting by visitingwww.proxyvote.com.

The Annual General Meeting of Shareholders is being convened for the following purposes, as more fully described in the accompanying proxy statement (the “Proxy Statement”):

1. To elect the two Class II director nominees named in the Proxy Statement to serve until the 2029 Annual General Meeting of Shareholders or until their successors are duly elected and qualified or until their earlier death, resignation, disqualification, or removal, as outlined below:

a. Jonathan Violin, Ph.D., is to be elected by the affirmative vote of a plurality of votes cast by holders of our Series A non-voting convertible preferred shares, par value $0.001 each in the capital of the Company (“Series A preferred shares”), voting together as a separate class on an as-converted to ordinary shares (as defined below) basis.

b. Susan Moran, M.D., MSCE, is to be elected by the affirmative vote of a plurality of votes cast by holders of our ordinary shares, par value $0.001 each in the capital of the Company (ordinary shares), and of any other class or series of voting shares (including the Series A preferred shares), voting together as a single class on an as-converted to ordinary shares basis.

2. To ratify the appointment of PricewaterhouseCoopers LLP as the independent registered public accounting firm of Crescent Biopharma, Inc. for its fiscal year ending December 31, 2026.

3. To approve, on a non-binding, advisory basis, the compensation for our named executive officers.

4. To approve, on a non-binding, advisory basis, the frequency of future advisory votes to approve the compensation for our named executive officers.

5. To conduct any other business properly brought before the meeting or any adjournments or postponements thereof.

These items of business are more fully described in the Proxy Statement accompanying this Notice.

The record date for the Annual General Meeting of Shareholders is April 7, 2026. Only holders of record of our Series A preferred shares and ordinary shares at the close of business on that date will be entitled to notice of the meeting, attend, and to vote at the meeting.

Notwithstanding the order of the resolutions on the notice to the Annual General Meeting, an adjournment proposal may be presented first to the shareholders if, based on the tabulated vote collected at the time of the Annual General Meeting, there are insufficient votes for, or otherwise in connection with, the approval of proposals 1 through 4.

Important Notice Regarding the Availability of Proxy Materials for the Annual General Meeting of Shareholders to be held virtually on June 2, 2026 via live audio-only webcast at www.virtualshareholdermeeting.com/CBIO2026The Proxy Statement and Annual Report to Shareholders are available at www.proxyvote.com.

OUR BOARD RECOMMENDS A VOTE “FOR” THE ELECTION OF THE TWO DIRECTOR NOMINEES NAMED IN THIS PROXY STATEMENT, “FOR” PROPOSALS 2 AND 3 AND “ONE-YEAR” FOR PROPOSAL 4.

By Order of the Board of Directors

/s/ Barbara Bispham Hale

Barbara Bispham Hale

Corporate Secretary

Waltham, Massachusetts

April 21, 2026

You are cordially invited to attend the meeting virtually. Whether or not you expect to attend the meeting virtually via live audio-only webcast, please complete, date, sign and return the proxy card or voting instruction form if sent to you, or vote over the telephone or the Internet as instructed in these materials, as promptly as possible in order to ensure your representation at the meeting. Even if you have voted by proxy, you may still vote electronically during the meeting.

PROXY STATEMENT

This Proxy Statement is furnished in connection with the solicitation by the Board of Directors of Crescent Biopharma, Inc. (“we,” “us,” “our,” “Crescent” or the “Company”) of proxies to be voted at our 2026 Annual General Meeting of Shareholders (the “Annual Meeting”). The following information is a summary only and does not contain all the information that you should consider in connection with this Proxy Statement. Please read the entire Proxy Statement carefully before voting.

Annual Meeting of Shareholders

• Date and Time: Tuesday, June 2, 2026 at 9:00 a.m. Eastern Time. Online check-in will begin at 8:45 a.m. Eastern Time and you should allow ample time for the check-in procedures.

• Location: The meeting will be held virtually via live audio-only webcast atwww.virtualshareholdermeeting.com/CBIO2026.

• Admission: To attend the meeting, you will need the 16-digit control number included in your Notice of Internet Availability of Proxy Materials, on your proxy card or on the instructions that accompanied your proxy materials.

• Record Date: April 7, 2026.

• Proxy Mailing Date: Beginning on or about April 21, 2026.

• Holders of ordinary shares, par value $0.001 each in the capital of the Company (“ordinary shares”), and Series A non-voting convertible preferred shares, par value $0.001 each in the capital of the Company (“Series A preferred shares” and such holders collectively, our “shareholders”), as of the Record Date are entitled to notice of, virtually attend, and vote at the Annual Meeting. Each ordinary share is entitled to one vote per share for the election of Susan Moran, M.D., MSCE, and one vote for each of the other proposals. Each Series A preferred share is convertible into 1,000 ordinary shares (subject to adjustment), and accordingly each Series A preferred share entitles the holder to 1,000 votes per Series A preferred share on an as-converted basis, which votes shall be cast together as a separate class for the election of Jonathan Violin, Ph.D., and together with the holders of ordinary shares as a single class for the election of Susan Moran, M.D., MSCE, and is not entitled to vote on any other proposal.

Voting Matters

Shareholders are being asked to vote on the following matters:

• Such plurality of Series A preferred shares voting on an as-converted to ordinary share basis.

** Such plurality of ordinary shares and Series A preferred shares voting on an as-converted to ordinary share basis together as a single class.

*** If no frequency receives the foregoing vote, then we will consider the option of ONE YEAR, TWO YEARS, or THREE YEARS that receives the highest number of votes cast to be the frequency recommended by shareholders.

The Proxy Statement and Annual Report to Shareholders are available atwww.proxyvote.com.