Cue 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. )

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☒ Definitive Proxy Statement

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Cue Biopharma, Inc.

(Name of Registrant as Specified in its Charter)

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To Our Stockholders:

We are pleased to invite you to attend the annual meeting of stockholders of Cue Biopharma, Inc., or the Annual Meeting. The Annual Meeting will be held exclusively via the Internet in a virtual meeting format on Wednesday, June 4, 2025 at 9:00 a.m. Eastern Time where you will be able to vote your shares electronically and submit questions during the meeting. You can attend the Annual Meeting online atwww.virtualshareholdermeeting.com/CUE2025, after entering the 16-digit control number found on your proxy card, voting instruction form or Notice Regarding Internet Availability of Proxy Materials, or the Notice, and following the instructions on the website.

The Notice of 2025 Annual Meeting of Stockholders and the Proxy Statement contain details of the business to be conducted at the Annual Meeting. Only stockholders of record at the close of business on April 11, 2025 will be entitled to notice of, and to vote at, the Annual Meeting.

Your vote is important. Regardless of whether you plan to attend the Annual Meeting online, we hope that you will vote as soon as possible. If you are the “record holder” of your shares, you may vote by proxy over the Internet, by telephone, or by mail by following the instructions on the Notice or the proxy card. If your shares are held in “street name,” meaning they are held for your account by a bank, brokerage firm or other nominee, you will receive instructions from your bank, brokerage firm or other nominee on how to vote your shares. Using these methods will ensure your representation at the Annual Meeting regardless of whether you attend the meeting online.

Thank you for your ongoing support of, and continued interest in, Cue Biopharma.

Very truly yours,

/s/ Daniel R. Passeri

Daniel R. Passeri

Chief Executive Officer

NOTICE OF 2025 ANNUAL MEETING OF STOCKHOLDERS

To Be Held on Wednesday, June 4, 2025

Dear Stockholder:

You are cordially invited to the 2025 Annual Meeting of Stockholders, or the Annual Meeting, of Cue Biopharma, Inc. The Annual Meeting will be held exclusively via the Internet in a virtual meeting format atwww.virtualshareholdermeeting.com/CUE2025 on Wednesday, June 4, 2025 at 9:00 a.m. Eastern Time. The stockholders will consider and vote on the following matters:

To adopt and approve an amendment to our Amended and Restated Certificate of Incorporation, as amended, to increase the number of authorized shares of our capital stock from 210,000,000 to 310,000,000 and increase the number of authorized shares of our common stock from 200,000,000 to 300,000,000 (Proposal 1);

The election of six nominees to the Board of Directors (Proposal 2);

The ratification of the appointment of RSM US LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2025 (Proposal 3);

The approval, on a non-binding advisory basis, of the compensation of our named executive officers (Proposal 4);

The approval of the Cue Biopharma, Inc. 2025 Stock Incentive Plan (Proposal 5); and

The transaction of any other business that may properly come before the Annual Meeting or any adjournment or postponement thereof.

Our stockholders of record as of the close of business on April 11, 2025, or the record date, are entitled to participate in and vote at the Annual Meeting. To participate in the Annual Meeting, including to vote and ask questions, stockholders of record should go to the meeting website atwww.virtualshareholdermeeting.com/CUE2025, enter the 16-digit control number found on your proxy card, voting instruction form, or Notice Regarding Internet Availability of Proxy Materials and follow the instructions on the website.

Instead of mailing to our stockholders a printed copy of our proxy materials, including this Proxy Statement, our 2024 Annual Report to Stockholders, which includes our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and a proxy card, we provide access to these materials over the Internet. We believe that providing our proxy materials over the Internet expedites stockholders’ receipt of proxy materials, lowers costs and reduces the environmental impact of our Annual Meeting.

We encourage all stockholders to attend the Annual Meeting online. However, whether or not you plan to attend the Annual Meeting online, we encourage you to read the Proxy Statement and submit your proxy or voting instructions as soon as possible. Please review the instructions on how to vote your shares online during the Annual Meeting as described in the Proxy Statement.

By the Order of the Board of Directors,

/s/ Colin Sandercock

Colin Sandercock

Senior Vice President, General Counsel and Secretary

Boston, Massachusetts

Important Notice Regarding Internet Availability of Proxy Materials for the 2025 Annual Meeting of Stockholders to be Held on June 4, 2025: You will be able to view the Notice Regarding Internet Availability of Proxy Materials, this Proxy Statement, our 2024 Annual Report to Stockholders, which includes our Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and a proxy card online at www.proxyvote.com or you can receive a free paper or email copy of the materials by requesting such materials. If you would like to request a copy of the materials for this and/or future stockholder meetings, you may (1) visit www.proxyvote.com; (2) call 1-800-579-1639; or (3) send an email to sendmaterial@proxyvote.com.