144 0001233539 XXXXXXXX LIVE 0001937653 Zymeworks Inc. 001-41535 108 Patriot Drive, Suite A Middletown DE 19709 302-274-8744 Leone D Patterson Former officer Common Stock Morgan Stanley Smith Barney

1 New York Plaza, 38th Floor New York NY 10004

128548 2978457.16 74836534 02/13/2026 Nasdaq Common Stock 02/13/2026 Exercise of options Issuer N 117255 02/13/2026 Exercise and sell to cover Common Stock 01/12/2026 Vesting of Restricted Stock Units Issuer N 10834 01/12/2026 Compensation Common Stock 01/06/2026 Purchased pursuant to Employee Stock Purchase Plan Issuer N 459 01/06/2026 Cash payment pursuant to Employee Stock Purchase Plan N Leone Patterson

c/o Zymeworks Inc. 108 Patriot Drive, Suite A Middletown DE 19709

Common Stock 01/12/2026 6832 154905.35 02/13/2026 /s/ Leone D Patterson