Zymeworks 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

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Filed by a Party other than the Registrant ☐

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NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

OF ZYMEWORKS INC.

AND

PROXY STATEMENT

FOR ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON DECEMBER 30, 2025

November 10, 2025

Notice of Annual Meeting of Stockholders

The 2025 annual meeting of stockholders (the “Meeting”) of Zymeworks Inc., a Delaware corporation (the “Company”), will be held on December 30, 2025, beginning at 9:00 a.m. Pacific Time. The Meeting will be conducted virtually via live audio webcast. If you are a stockholder of record at the close of business on November 3, 2025 (the “Record Date”) you are invited to attend the Meeting virtually by visiting meetnow.global/MZKC5MK, where you will be able to listen to the Meeting live, submit questions and vote online. If you plan to attend the Meeting, please follow the registration instructions as outlined in this proxy statement.

The Meeting will be held for the following purposes as more fully described in the accompanying proxy statement:

The business to be considered at the Meeting may be considered at the Meeting or at any adjournment or postponement of the Meeting.

You are entitled to vote on the matters listed above if you were a stockholder of the Company or a holder of exchangeable shares (the “exchangeable shares”) of Zymeworks ExchangeCo Ltd., a company existing under the laws of the Province of British Columbia and an indirect subsidiary of the Company, as of the Record Date. However, you are only entitled to attend the Meeting if you were a stockholder of record on the Record Date. Street name stockholders and holders of exchangeable shares will need to obtain a valid proxy in order to virtually attend and vote at the Meeting. For ten days prior to the Meeting, a complete list of stockholders of record entitled to vote at the Meeting will be available for examination by any stockholder for any purpose relevant to the Meeting. If you would like to view the list, please contact our Corporate Secretary to schedule an appointment by calling 302-274-8744 or writing to Zymeworks Inc., 108 Patriot Drive, Suite A, Middletown, Delaware 19709.

Whether or not you plan to attend the virtual Meeting, we encourage you to read this proxy statement and promptly vote your shares. You may submit a proxy by telephone, via the Internet or by mail. For specific instructions on how to vote your shares, please refer to the section entitled “Questions and Answers—How You Can Vote” beginning on page 4 and to the instructions on your proxy or voting instruction card. Interested stockholders or holders of exchangeable shares may also contact Kingsdale Advisors at 1-855-476-7981 (toll-free in North America) or 437-561-5034 (text or collect outside North America) or by email atcontactus@kingsdaleadvisors.com.

/s/ Kenneth Galbraith

Kenneth Galbraith Chair of the Board of Directors, Chief Executive Officer and President Vancouver, British Columbia November 10, 2025

Availability of Proxy Statement Materials for the Annual Meeting of Stockholders to be Held on December 30, 2025: The Notice of Internet Availability of Proxy Materials (the “Notice”) containing instructions on how to access our proxy statement, notice of annual meeting, form of proxy and our annual report, is first being sent or given on or about November 18, 2025 to all stockholders and holders of exchangeable shares entitled to vote at the Meeting. The Notice provides instructions on how to vote online or by telephone and includes instructions on how to receive a paper copy of proxy materials by mail. The proxy materials and our annual report can be accessed as of November 10, 2025 by visiting https://www.envisionreports.com/ZYME.

Unless the context otherwise requires or unless otherwise expressly stated, all references in this notice and the accompanying proxy statement to “Zymeworks,” the “Company,” “we,” “us” and “our” (i) for periods on or prior to October 12, 2022, refer to Zymeworks BC Inc. and its subsidiaries and (ii) for periods on and after October 13, 2022, refer to Zymeworks Inc. and its subsidiaries. Similarly, unless the context otherwise requires or unless otherwise expressly stated, all references in this notice and the accompanying proxy statement to common stock or common shares (i) for periods on or prior to October 12, 2022, refer to common shares of Zymeworks BC Inc. and (ii) for periods on and after October 13, 2022, refer to common stock of Zymeworks Inc.