X0407 4 2023-06-06 0 0001664710 Keros Therapeutics, Inc. KROS 0001568077 Kariv Tomer C/O KEROS THERAPEUTICS, INC. 1050 WALTHAM STREET, SUITE 302 LEXINGTON MA 02421 1 0 1 0 0 Stock Option (right to buy) 48.79 2023-06-06 4 A 0 10000 0.00 A 2033-06-05 Common Stock 10000 10000 D The option shall vest in equal quarterly installments over the 12 months following the date of grant, provided that the grant will in any case be fully vested on the date of Issuer's 2024 annual meeting of stockholders, subject to the Reporting Person continuing to provide service through each such date. /s/ Keith Regnante, Attorney-in-Fact 2023-06-08