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

31641 715086.60 74836534 02/17/2026 Nasdaq Common Stock 02/17/2026 Exercise of options Issuer N 31641 02/17/2026 Exercise and sell to cover N Leone Patterson

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

Common Stock 01/12/2026 6832 154905.35 Leone Patterson

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

Common Stock 02/13/2026 117255 2706749.60 02/17/2026 /s/ Leone D Patterson