Zymeworks Inc. — Director's Dealing 2025

Jun 27, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Zymeworks Inc. (ZYME)
CIK: 0001937653
Period of Report: 2025-06-26

Reporting Person: EcoR1 Capital, LLC (Director, 10% Owner)
Reporting Person: NODELMAN OLEG (Director, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-06-26	Common Stock	X	5086480	$0.0001	Acquired	22970388	Indirect
2025-06-26	Common Stock	F	41	$12.71	Disposed	22970388	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-06-26	Pre-Funded Warrants (right to acquire)	$0.0001	X	5086521	Disposed		Common Stock (5086521)	Indirect

Footnotes

F1: The reporting persons are EcoR1 Capital, LLC ("EcoR1"), Oleg Nodelman and EcoR1 Capital Fund Qualified, L.P. ("Qualified Fund"). EcoR1 is the general partner and investment adviser of private funds, including Qualified Fund (the "Funds"). Mr. Nodelman is the manager and controlling owner of EcoR1. EcoR1 is filing this Form 4 for itself and Qualified Fund. The filers are filing this Form 4 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934. The Funds hold these securities directly for the benefit of their investors. EcoR1 may be deemed to indirectly beneficially own them as the investment adviser to the Funds. Mr. Nodelman may be deemed to indirectly beneficially own them as the control person of EcoR1. The filers disclaim beneficial ownership of the securities except to the extent of their respective pecuniary interests therein.

F2: Qualified Fund acquired 4,818,424 shares of Common Stock in connection with the exercise of the pre-funded warrants.

F3: After the transactions reported herein, Qualified Fund held 21,582,563 shares of the Issuer's Common Stock.

F4: On June 26, 2025,the reporting persons exercised pre-funded warrants to purchase 5,086,521 shares of the Issuer's Common Stock for $0.0001 per share. The reporting persons paid the exercise price on a cashless basis, resulting in the Issuer withholding 41 of the warrant shares (including 38 warrant shares issuable to Qualified Fund) to pay the exercise price and issuing to the reporting persons the remaining 5,086,480 shares.

F5: Qualified Fund exercised 4,818,462 of the pre-funded warrants reported in this transaction.

F6: The pre-funded warrants did not have an expiration date.