X0306 4 2019-02-28 0001177648 ENANTA PHARMACEUTICALS INC ENTA 0001586660 Golumbeski George C/O ENANTA PHARMACEUTICALS, INC. 500 ARSENAL STREET WATERTOWN MA 02472 1 0 0 0 Stock Option (right to buy) 102.54 2019-02-28 4 A 0 5000 0 A 2029-02-28 Common Stock 5000 5000 D Such option will become exercisable monthly in substantially equal installments over one year, beginning from the date of grant (February 28, 2019), with the final monthly installment vesting on the nearest trading day on the Nasdaq Global Select Market preceding the 2020 annual meeting of stockholders. /s/ Nathaniel S. Gardiner as attorney-in-fact 2019-03-01