X0306 4 2020-03-12 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 2020-03-12 4 M 0 3000 30.00 A 27605 D Common Stock 16645 I By grantor retained annuity trust Stock Option (right to buy) 30.00 2020-03-12 4 M 0 3000 0 D 2026-11-18 Common Stock 3000 17000 D On April 10, 2019, the reporting person contributed 16,645 shares of common stock to a grantor retained annuity trust for the benefit of himself and his two adult children. This option to purchase a total of 25,000 shares of common stock became or will become exercisable (subject to the optionholder's continued employment) quarterly in substantially equal installments (any fractional shares to be cumulated and to become exercisable at the end of the earliest succeeding quarterly period in which a whole share equivalent is accumulated) over four years from the date of grant (November 18, 2016). /s/ Nathaniel S. Gardiner 2020-03-16