Kenneth Galbraith - 12 Jan 2026 Form 4 Insider Report for Zymeworks Inc. (ZYME)

Role: Chair & CEO, Director
Signature: /s/ Daniel Dex, Attorney-in-Fact
Issuer symbol: ZYME
Transactions as of: 12 Jan 2026
Net transactions value: -$689,819
Form type: 4
Filing time: 12 Jan 2026, 19:07:56 UTC
Previous filing: 05 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Galbraith Kenneth	Chair & CEO, Director	C/O ZYMEWORKS INC., 108 PATRIOT DRIVE, SUITE A, MIDDLETOWN	/s/ Daniel Dex, Attorney-in-Fact	12 Jan 2026	0001567045

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ZYME	Common Stock	Options Exercise	$0	+64,000	+33%	$0.000000	257,266	12 Jan 2026	Direct	F1
transaction	ZYME	Common Stock	Sale	$689,819	-30,424	-12%	$22.67	226,842	12 Jan 2026	Direct	F2, F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ZYME	Restricted Stock Unit	Options Exercise	$0	-64,000	-33%	$0.000000	128,000	12 Jan 2026	Common Stock	64,000		Direct	F4, F5
transaction	ZYME	Stock Option (Right to Buy)	Award	$0	+216,000		$0.000000	216,000	12 Jan 2026	Common Stock	216,000	$23.16	Direct	F6
transaction	ZYME	Restricted Stock Unit	Award	$0	+144,000		$0.000000	144,000	12 Jan 2026	Common Stock	144,000		Direct	F4, F7
transaction	ZYME	Performance Stock Unit	Award	$0	+222,000		$0.000000	222,000	12 Jan 2026	Common Stock	222,000		Direct	F8, F9

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents shares of common stock issued upon vesting of one third of the restricted stock units ("RSUs") granted on January 10, 2025.
F2	Represents shares of common stock sold to cover tax withholding obligations and other applicable fees in connection with the vesting of RSUs pursuant to mandatory "sell to cover" provisions contained in the Reporting Person's applicable RSU grant agreement, and does not represent a discretionary sale by the Reporting Person. The Reporting Person did not sell or otherwise dispose of any of the shares reported on this Form 4 for any reason other than to cover required taxes and fees.
F3	The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $22.49 to $23.05, inclusive. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
F4	Each RSU represents the contingent right to receive, upon vesting of the RSU, one share of common stock.
F5	The RSUs were granted on January 10, 2025 and vest in three equal annual installments beginning on the first anniversary of grant date.
F6	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.
F7	RSUs vest in four equal annual installments beginning on first anniversary of grant date.
F8	Each performance restricted stock unit ("PSU") represents a contingent right to receive one share of common stock. The amount reported is the maximum number of PSUs that may be earned upon achievement of certain cumulative total shareholder return ("TSR") goals over a three-year performance period ending on January 12, 2029 (or in some cases at earlier times). Between 50% and 200% of the target number of 111,000 PSUs ("Target Number") may be earned upon achievement of such TSR goals. 50% of the Target Number may be earned upon achievement of relative TSR goals if the Company's TSR for the performance period equals or exceeds a prespecified percentile for the Nasdaq Biotech Index. The PSUs will only vest at the end of the three-year performance period if the reporting person's service to the Company continues through such time that the board of directors of the Company certifies the achievement of TSR goals,
F9	(Continued from footnote 8) except in certain limited cases (such as if service to the Company is terminated by the Company without cause or in case of a change of control).