X0306 4 2020-06-18 0 0001463361 Unity Biotechnology, Inc. UBX 0001416180 Leonard Keith R C/O UNITY BIOTECHNOLOGY, INC. 285 EAST GRAND AVENUE SOUTH SAN FRANCISCO CA 94080 1 0 0 0 Stock Option (Right to Buy) 9.14 2020-06-18 4 A 0 50000 0.00 A 2030-06-17 Common Stock 50000 50000 D The shares subject to the option will vest and become exercisable with respect to 1/36th of the total number of shares subject to the option in successive, equal monthly installments measured from June 18, 2020, subject to the Reporting Person's continued service relationship with the Issuer on each vesting date. /s/ Tamara L. Tompkins, Attorney-in-Fact for Keith R. Leonard 2020-06-22