X0306 4 2021-06-24 0 0001463361 Unity Biotechnology, Inc. UBX 0001727640 Sullivan Lynne Marie C/O UNITY BIOTECHNOLOGY, INC. 285 EAST GRAND AVENUE SOUTH SAN FRANCISCO CA 94080 0 1 0 0 CFO & Head of Corp. Dev. Common Stock, $0.0001 par value 2021-06-24 4 A 0 30833 0.00 A 270833 D Stock Option (Right to Buy) 4.18 2021-06-24 4 A 0 123333 0.00 A 2031-06-23 Common Stock 123333 123333 D Represents Restricted Stock Units ("RSUs") which vest in equal annual installments over a three year period measured from June 24, 2021. Each RSU represents a contingent right to receive one share of Common Stock of the Issuer. Includes RSUs which vest over time measured from the grant date. Shares subject to the stock option vest and become exercisable in successive, equal monthly installments over a 48-month period commencing on June 24, 2021 (the "Vesting Commencement Date"), so that 100% of the shares become fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date, subject to Reporting Person's continued employment or service relationship with the Issuer on each such vesting date. /s/ Alexander Nguyen, Attorney-in-Fact for Lynne Marie Sullivan 2021-06-28