X0306 4 2020-12-15 0001177648 ENANTA PHARMACEUTICALS INC ENTA 0001607643 Gardiner Nathaniel S. C/O ENANTA PHARMACEUTICALS, INC. 500 ARSENAL STREET WATERTOWN MA 02472 0 1 0 0 Sr. VP & General Counsel Common Stock 2020-12-15 4 M 0 5250.0 A 43788 D Common Stock 2020-12-15 4 F 0 1540.0 42.52 D 42248 D Common Stock 16645.0 I By grantor retained annuity trusts Restricted Stock Units 2020-12-15 4 M 0 5250.0 0.0 D Common Stock 5250.0 0.0 D Represents shares of ENTA common stock subject to a restricted stock unit award granted on November 18, 2016 that vested on November 18, 2020. The settlement and issuance of the shares was subject to continued employment and occurred on December 15, 2020. Restricted stock units convert into ENTA common stock on a one-for-one basis. Represents the number of shares of ENTA common stock forfeited by the reporting person to cover withholding taxes due as a result of settlement of the restricted stock unit award. These shares are held by grantor retained annuity trusts created by the reporting person for the benefit of himself and his two adult children. On November 18, 2016, the reporting person was granted 10,500 restricted stock units. 5,250 restricted stock units have previously vested and the remainder vested on November 18, 2020. /s/ Nathaniel S. Gardiner 2020-12-16