SCHEDULE 13G/A 0001831942 XXXXXXXX LIVE 1 Common Stock, $0.01 par value 09/30/2025 0001590750 Viridian Therapeutics, Inc.\DE 92790C104 221 Crescent Street Suite 103A Waltham MA 02453 Rule 13d-1(c) Commodore Capital LP DE 0.00 3200000.00 0.00 3200000.00 3200000.00 3.9 IA PN Commodore Capital Master LP E9 0.00 3200000.00 0.00 3200000.00 3200000.00 3.9 PN Viridian Therapeutics, Inc.\DE 221 Crescent Street, Suite 103A, Waltham, MASSACHUSETTS, 02453. Commodore Capital LP Commodore Capital Master LP Each a "Filer." The address for Commodore Capital LP is 444 Madison Avenue, Floor 35, New York, NY 10022. The address for Commodore Capital Master LP is c/o Maples Corporate Services Limited, Ugland House, South Church Street, PO Box 309, Grand Cayman KY1-1104, Cayman Islands. See Item 4 of the cover page for each Filer. Y See Item 9 of the cover page for each Filer. Commodore Capital LP (the "Firm") is the investment manager to Commodore Capital Master LP. As of September 30, 2025 the Firm may be deemed to beneficially own an aggregate of 3,200,000 shares of Common Stock, $0.001 par value of Viridian Therapeutics, Inc. (the "Issuer"). The Firm, as the investment manager to Commodore Capital Master LP, may be deemed to beneficially own these securities. Michael Kramarz and Robert Egen Atkinson are the managing partners of the Firm and exercise investment discretion with respect to these securities. Ownership percentages are based on 82,229,158 Common Shares reported as issued and outstanding as of September 30, 2025 in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 5, 2025. See Item 11 of the cover page for each Filer. See Item 5 of the cover page for each Filer. See Item 6 of the cover page for each Filer. See Item 7 of the cover page for each Filer. See Item 8 of the cover page for each Filer. Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above 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. Exhibit 1: Joint Filing Agreement Commodore Capital LP Michael Kramarz 11/14/2025 Commodore Capital Master LP Michael Kramarz 11/14/2025