Zymeworks Reports Incentive Grant Pursuant to Nasdaq Stock Market Rule 5635(c) Page 1

VANCOUVER, British Columbia, Sept. 3, 2024 (GLOBE NEWSWIRE) — Zymeworks Inc. (Nasdaq: ZYME), a clinical-stage biotechnology company developing a diverse pipeline of novel, multifunctional biotherapeutics to advance the standard of care for difficult-to-treat diseases, today announced, pursuant to Nasdaq Stock Market Rule 5635(c) (the “Nasdaq Rule”), an equity award to Ms. Leone Patterson, Executive Vice President and Chief Business and Financial Officer of Zymeworks.

In accordance with the Nasdaq Rule, Zymeworks has approved the grant of the following stock award to Ms. Patterson as a material inducement for Ms. Patterson to begin employment with Zymeworks: Effective September 1, 2024, the date on which her employment with Zymeworks commenced (the “Start Date”), a stock option to purchase 360,000 shares of the Company's common stock (the “Option”). The Option has an exercise price per share of $11.73, which is equal to the closing price of the Company's common stock on August 30, 2024, and has a maximum term of 10 years.