Amendment: SEC Form SCHEDULE 13D/A filed by Viridian Therapeutics Inc.

Item 3 of the Statement is hereby amended and supplemented as follows: In aggregate, the Reporting Persons have voting and dispositive power over 17,201,800 shares of Common Stock, which is comprised of (a) 5,090,928 shares of Common Stock, and (b) an aggregate of 12,110,872.18 (rounded to 12,110,872 shares for purposes of reporting in this Schedule 13D) shares of Common Stock issuable upon conversion of 133,191 shares of Series A Preferred Stock and 48,463 shares of Series B Preferred Stock, the conversion of each of which is subject to a beneficial ownership limitation of 19.99% of the outstanding Common Stock. On May 11, 2026, Fund II purchased a total of 1,176,470 shares of Common Stock for an aggregate price of $19,999,990.00 in an underwritten public offering (the "Offering"). The shares were purchased with working capital. Fairmount and Fairmount GP II do not own any shares of Common Stock, Series A Preferred Stock or Series B Preferred Stock directly. Fairmount and Fairmount GP II are deemed to beneficially own the shares Common Stock, Series A Preferred Stock and Series B Preferred Stock held by Fund II. Fairmount and Fairmount GP II disclaim beneficial ownership of such shares of Common Stock, Series A Preferred Stock and Series B Preferred Stock except to the extent of their pecuniary interest therein.

Item 4 is hereby amended and supplemented as follows: Fund II purchased the shares of Common Stock referenced in Item 3 for investment purposes.

The information in rows 11 and 13 of each of the cover pages (including the explanatory note in the "Comments") of this Amendment No. 8 is incorporated by reference herein.

The information in rows 7 through 10 of each of the cover pages of this Amendment No. 8 is incorporated by reference herein.

On May 11, 2026, Fund II purchased in the Offering a total of 1,176,470 shares of Common Stock of the Company at a purchase price of $17 per share for an aggregate purchase price of $19,999,990.00.

Fairmount is the investment manager to Fund II and has voting and dispositive power over shares of Common Stock held on behalf of Fund II. Fairmount GP II serves as the general partner to Fund II and is deemed to share voting and dispositive power over shares of Common Stock held on behalf of Fund II in its capacity as general partner.

Lock-Up Agreement In connection with the Offering that closed on May 11, 2026, the Fund II entered into a customary lock-up letter agreement (the "Lock-Up Agreement") with Jefferies LLC, Leerink Partners LLC, and Goldman Sachs & Co. LLC as the representatives of the underwriters (the "Representatives") to an underwriting agreement with the Company. Pursuant to the Lock-Up Agreement, Fund II agreed to refrain from selling shares of the Company's securities without the consent of the Representatives, and other customary lock-up conditions, for a period of 60 days from the date of the Company's final prospectus supplement related to the offering. The foregoing description of the Lock-Up Agreement does not purport to be complete and is qualified in its entirety by reference to the form of the Lock-Up Agreement, which is filed as Exhibit 99.2 to this Schedule 13D and incorporated herein by reference.

99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 of the Reporting Persons' Schedule 13D filed with the SEC on October 27, 2025). 99.2 Lock-Up Agreement (incorporated by reference to Exhibit A to the Underwriting Agreement filed as Exhibit 1.1 of the Company's Form 8-K filed with the SEC on May 11, 2026).