X0306 4 2022-12-16 0001177648 ENANTA PHARMACEUTICALS INC ENTA 0001571211 Luly Jay R. C/O ENANTA PHARMACEUTICALS, INC. 500 ARSENAL STREET WATERTOWN MA 02472 1 1 0 0 President and CEO Common Stock 2022-12-16 4 M 0 16149 14.18 A 789954 D Common Stock 2022-12-16 4 M 0 13851 14.00 A 803805 D Common Stock 2022-12-16 4 S 0 7800 43.59 D 796005 D Common Stock 2022-12-16 4 S 0 8597 44.54 D 787408 D Common Stock 2022-12-16 4 S 0 13603 45.49 D 773805 D Stock Option (Right to Buy) 14.18 2022-12-16 4 M 0 16149 0 D 2022-12-26 Common Stock 16149 0 D Stock Option (Right to Buy) 14.00 2022-12-16 4 M 0 13851 0 D 2023-03-21 Common Stock 13851 27912 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in September 2022. The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $43.29 to $43.99, inclusive. The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $44.04 to $44.93, inclusive. The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $45.00 to $45.85, inclusive. 100% of the shares subject to the option are fully vested and exercisable. On March 21, 2013, the reporting person was granted an option to purchase 83,526 shares of common stock, which becomes reportable on Form 4 only if and to the extent that the option becomes exercisable. The option becomes exercisable in up to nine installments, based on Enanta's achievement of certain clinical milestones with respect to three or more programs that progress in clinical development. As of the date of this filing, a total of 50% of the shares subject to the option have become exercisable. The reporting person undertakes to provide to Enanta Pharmaceuticals, Inc., any security holder of Enanta Pharmaceuticals, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes 2 through 4 above. /s/ Nathaniel S. Gardiner as attorney-in-fact 2022-12-16