Amendment No. 3 to Schedule 13D for Apogee Therapeutics, Inc.

This Amendment No. 3 to Schedule 13D, filed by Fairmount Funds Management LLC, Fairmount Healthcare Fund II L.P., Peter Harwin, and Tomas Kiselak, reports the entry into a lock-up agreement with Apogee Therapeutics, Inc. in connection with the company's underwritten public offering. The lock-up agreement restricts the sale of shares for 60 days from the date of the final prospectus supplement. The number of shares of Common Stock and Non-Voting Common Stock beneficially owned by the reporting persons has not changed since Amendment No. 2. The filing also updates the principal business and occupation of the reporting persons. The reporting persons collectively own 9.81% of the company's Common Stock, including shares issuable upon conversion of Non-Voting Common Stock, subject to a beneficial ownership limitation of 9.99%.