X0306 4 2023-01-05 0 0001937653 Zymeworks Inc. ZYME 0001567045 Galbraith Kenneth C/O ZYMEWORKS INC. 108 PATRIOT DRIVE, SUITE A MIDDLETOWN DE 19709 1 1 0 0 Chair & CEO Stock Option (Right to Buy) 8.00 2023-01-05 4 A 0 215000 0.00 A 2033-01-04 Common Stock 215000 215000 D Restricted Stock Unit 2023-01-05 4 A 0 143000 0.00 A Common Stock 143000 143000 D Stock options vest as follows: (i) 25% of underlying shares of common stock on first anniversary of grant date and (ii) remainder of underlying shares of common stock in 36 equal monthly installments on last day of month following first anniversary of grant date. Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock. The RSUs vest in three equal annual installments beginning on January 5, 2024. /s/ Daniel Dex, Attorney-in-Fact 2023-01-06