SCHEDULE 13G/A 0001201001 XXXXXXXX LIVE 1 Common Stock, par value $0.0001 per share 09/30/2025 0001736730 CAMP4 Therapeutics Corporation 13463J101 One Kendall Square Building 1400 West, 3rd Floor Cambridge MA 02139 Rule 13d-1(d) HarbourVest Partners L.P. DE 0 1271948 0 1271948 1271948 N 2.7 IA HarbourVest Partners, LLC DE 0 1271948 0 1271948 1271948 N 2.7 IA SMRS-TOPE LLC DE 1271948 0 1271948 0 1271948 N 2.7 OO HVST-TOPE LLC DE 0 1271948 0 1271948 1271948 N 2.7 OO CAMP4 Therapeutics Corporation One Kendall Square; Building 1400 West, 3rd Floor; Cambridge, MA 02139 HarbourVest Partners, LLC HarbourVest Partners L.P. HVST-TOPE LLC SMRS-TOPE LLC SMRS-TOPE LLC, HVST-TOPE LLC, HarbourVest Partners L.P. and HarbourVest Partners, LLC have entered into a Joint Filing Agreement, dated September [ ], 2025, a copy of which is filed with this Schedule 13G as Exhibit 99.1, pursuant to which such reporting persons agreed to file this statement and any amendments thereto jointly in accordance with the provisions of Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended. The principal business office of each reporting person is One Lincoln Street, Suite 1700, Boston, MA 02111. Reporting entities are all organized and exist under the laws of the State of Delaware. Y Consists of 1,271,948 shares of common stock owned directly by SMRS-TOPE LLC. HarbourVest Partners, LLC ("HarbourVest") is the General Partner of HarbourVest Partners L.P., which is the Manager of HVST-TOPE LLC, which is the Managing Member of SMRS-TOPE LLC. Each of HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC may be deemed to have a beneficial interest in the shares held by SMRS-TOPE LLC. Voting and investment power over the securities owned directly by SMRS-TOPE LLC is exercised by the Investment Committee of HarbourVest. Each of HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC and the members of the HarbourVest Investment Committee disclaim beneficial ownership of the shares held directly by SMRS-TOPE LLC. 2.7% (based on 46,842,126 shares of common stock outstanding, which includes the 26,681,053 shares of common stock issued and sold to certain investors as reported in the Issuer's Current Report on Form 8-K, filed with the SEC on September 10, 2025 and the 20,161,073 shares of common stock outstanding as of August 5, 2025 as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the SEC on August 14, 2025). SMRS-TOPE LLC has the sole power to vote or to direct the vote of 1,271,948 shares of common stock. HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC may be deemed to have shared power to vote or direct the vote of 1,271,948 shares of common stock. Each of HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC disclaim beneficial ownership of such shares. SMRS-TOPE LLC has the sole power to dispose or to direct the disposition of 1,271,948 shares of common stock. HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC may be deemed to have shared power to dispose or direct the disposition of 1,271,948 shares of common stock. Each of HarbourVest, HarbourVest Partners L.P. and HVST-TOPE LLC disclaim beneficial ownership of such shares. N Y N See Item 4 above. Y Y Y Y HarbourVest Partners L.P. By: HarbourVest Partners, LLC, its General Partner; /s/ Adam Freedman 10/01/2025 HarbourVest Partners, LLC /s/ Adam Freedman 10/01/2025 SMRS-TOPE LLC By: HVST-TOPE LLC, its Managing Member; HarbourVest Partners L.P., its Manager; HarbourVest Partners, LLC, its General Partner; /s/ Adam Freedman 10/01/2025 HVST-TOPE LLC By: HarbourVest Partners L.P., its Manager; HarbourVest Partners, LLC, its General Partner; /s/ Adam Freedman 10/01/2025