SCHEDULE 13D/A 0000929638-23-001060 0001583977 XXXXXXXX LIVE 4 Common Stock 10/22/2025 false 0001840439 09077A106 Biomea Fusion, Inc.

1599 INDUSTRIAL ROAD SAN CARLOS CA 94070

Neb Obradovic 857-702-0386 Cormorant Asset Management, L.P. 200 Clarendon Street, 52nd Floor Boston MA 02116 0001618442 Cormorant Global Healthcare Master Fund, LP b WC E9 0 477791 0 477791 477791 N 0.69 PN 0001618451 Cormorant Global Healthcare GP, LLC b AF DE 0 477791 0 477791 477791 N 0.69 OO 0001817320 Cormorant Private Healthcare Fund III LP b WC DE 0 456855 0 456855 456855 N 0.66 PN Y Cormorant Private Healthcare GP III, LLC b AF DE 0 456855 0 456855 456855 N 0.66 OO 0001583977 Cormorant Asset Management, LP b AF DE 0 950000 0 950000 950000 N 1.37 PN 0001599214 Chen Bihua b AF X1 110792 950000 110792 950000 1060792 N 1.53 IN Common Stock Biomea Fusion, Inc. 1599 INDUSTRIAL ROAD SAN CARLOS CA 94070 This Amendment No. 4 to Schedule 13D (this "Amendment") relates to Common Stock of Biomea Fusion, Inc., a Delaware corporation (the "Issuer" or the "Company"). The address of the principal executive offices of the Issuer is 1599 Industrial Road, San Carlos, CA 94070. This Amendment is being filed by the Reporting Persons to amend the Schedule 13D that was filed on April 30, 2021, as amended by Amendment No. 1 filed on April 3, 2023, Amendment No. 2 filed on July 22, 2025, and Amendment No. 3 filed on October 10, 2025 (as so amended, the "Schedule 13D"). Unless otherwise indicated, all capitalized terms used herein but not defined herein shall have the same meaning as in the Schedule 13D. Cormorant Global Healthcare Master Fund, LP Cormorant Global Healthcare GP, LLC Cormorant Private Healthcare Fund III, LP Cormorant Private Healthcare GP III, LLC Cormorant Asset Management, LP Bihua Chen 200 Clarendon Street, 52nd Floor Boston, MA 02116 Cormorant Global Healthcare Master Fund, LP - Cayman Islands Cormorant Global Healthcare GP, LLC - Delaware Cormorant Private Healthcare Fund III, LP - Delaware Cormorant Private Healthcare GP III, LLC - Delaware Cormorant Asset Management, LP - Delaware Bihua Chen - United States See Items 7-13 of the cover page and Item 2. See Items 7-13 of the cover page and Item 2. The percentages reported herein with respect to the Reporting Persons' holdings are calculated based upon (i) a statement in a Prospectus filed by the Issuer on October 7, 2025 that there would be 69,322,377 shares of Common Stock outstanding following the closing of a public offering described therein, and (ii) a statement in a Current Report on Form 8-K filed by the Issuer on October 7, 2025 reporting that the public offering was expected to close on October 8, 2025. The shares reported for Bihua Chen reflect shares of Common Stock that she has the right to receive within 60 days upon the exercise of stock options granted to her in her capacity as a director of the Issuer. The Reporting Persons effected the following transactions in the Company's Common Stock in the 60 day period beginning on the date requiring the filing of this Schedule 13D: (i) on October 22, 2025, the Reporting Persons sold an aggregate of 820,872 shares of Common Stock in open-market transactions at prices ranging from $1.42 to $1.58 per share (weighted-average price $1.48 per share); and (ii) on October 23, 2025, the Reporting Persons sold an aggregate of 1,800,000 shares of Common Stock in open-market transactions at prices ranging from $1.35 to $1.51 per share (weighted-average price $1.41 per share). The Reporting Persons undertake to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased at each price of the transactions reported in this Schedule 13D. Not applicable. As a result of the transactions described herein, as of October 22, 2025, the Reporting Persons ceased to be the beneficial owners of more than five percent of the Issuer's outstanding Common Stock. Cormorant Global Healthcare Master Fund, LP /s/ CORMORANT GLOBAL HEALTHCARE MASTER FUND, LP By: Cormorant Global Healthcare GP, LLC, its General Partner 10/24/2025 Cormorant Global Healthcare GP, LLC /s/ Bihua Chen 10/24/2025 Cormorant Private Healthcare Fund III LP /s/ CORMORANT PRIVATE HEALTHCARE FUND III, LP By: Cormorant Private Healthcare GP III, LLC, its General Partner 10/24/2025 Cormorant Private Healthcare GP III, LLC /s/ Bihua Chen 10/24/2025 Cormorant Asset Management, LP /s/ CORMORANT ASSET MANAGEMENT, LP By: Cormorant Asset Management GP, LLC, its General Partner 10/24/2025 Chen Bihua /s/ Bihua Chen 10/24/2025