SCHEDULE 13G/A 0001425738 XXXXXXXX LIVE 6 Common Stock, par value $0.00001 per share 09/30/2025 0001937653 Zymeworks Inc. 98985Y108 108 Patriot Drive, Suite A Middletown DE 19709 Rule 13d-1(b) Redmile Group, LLC DE 0.00 3705750.00 0.00 3705750.00 3705750.00 N 4.9 IA OO Redmile Group, LLC's beneficial ownership of the Issuer's common shares ("Common Stock") is comprised of 3,705,750 shares of Common Stock owned by certain private investment vehicles managed by Redmile Group, LLC (collectively, the "Redmile Clients"). The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of such Redmile Clients. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any. Percentage based on the sum of (i) 75,166,196 shares of Common Stock outstanding as of August 5, 2025, as reported by the Issuer in its Form 10-Q for the quarterly period ended June 30, 2025 filed with the Securities and Exchange Commission (the "SEC") on August 7, 2025 (the "Form 10-Q"); plus (ii) 415,000 shares of Common Stock issued by the Issuer in a private placement as of August 12, 2025, as reported by the Issuer in its Form 8-K filed with the SEC on August 11, 2025 (the "Form 8-K"). Jeremy C. Green X0 0.00 3705750.00 0.00 3705750.00 3705750.00 N 4.9 HC IN Jeremy C. Green's beneficial ownership of the Common Stock is comprised of 3,705,750 shares of Common Stock owned by certain Redmile Clients. The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of such Redmile Clients. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any. Percentage based on the sum of (i) 75,166,196 shares of Common Stock outstanding as of August 5, 2025, as reported by the Issuer in the Form 10-Q; plus (ii) 415,000 shares of Common Stock issued by the Issuer in a private placement as of August 12, 2025, as reported by the Issuer in the Form 8-K. Zymeworks Inc. 108 Patriot Drive, Suite A, Middletown, DE, 19709 Redmile Group, LLC Jeremy C. Green Redmile Group, LLC One Letterman Drive Building D, Suite D3-300 The Presidio of San Francisco San Francisco, California 94129 Jeremy C. Green c/o Redmile Group, LLC (NY Office) 45 W. 27th Street, Floor 11 New York, NY 10001 Redmile Group, LLC: Delaware Jeremy C. Green: United Kingdom N IA HC Redmile Group, LLC - 3,705,750 (1) Jeremy C. Green - 3,705,750 (1) Redmile Group, LLC - 4.9% (2) Jeremy C. Green - 4.9% (2) Redmile Group, LLC - 0 Jeremy C. Green - 0 Redmile Group, LLC - 3,705,750 (1) Jeremy C. Green - 3,705,750 (1) Redmile Group, LLC - 0 Jeremy C. Green - 0 Redmile Group, LLC - 3,705,750 (1) Jeremy C. Green - 3,705,750 (1) (1) The shares of the Issuer's Common Stock reported herein are held by certain Redmile Clients for which Redmile Group, LLC is the investment manager/adviser and, in such capacity, exercises voting and investment power over all of the shares of Common Stock held by the Redmile Clients and may be deemed to be the beneficial owner of these shares. Jeremy C. Green serves as the principal of Redmile Group, LLC and also may be deemed to be the beneficial owner of these shares. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any. (2) Percentage based on the sum of (i) 75,166,196 shares of Common Stock outstanding as of August 5, 2025, as reported by the Issuer in the Form 10-Q; plus (ii) 415,000 shares of Common Stock issued by the Issuer in a private placement as of August 12, 2025, as reported by the Issuer in the Form 8-K. N Y Y N See the response to Item 4. Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. Redmile Group, LLC /s/ Jeremy C. Green 11/14/2025 Jeremy C. Green /s/ Jeremy C. Green 11/14/2025