X0508 4 2023-11-20 0 0001783183 Phathom Pharmaceuticals, Inc. PHAT 0001363812 Henderson Molly C/O PHATHOM PHARMACEUTICALS, INC. 100 CAMPUS DRIVE, SUITE 102 FLORHAM NJ 07932 0 1 0 0 CFO and CBO 0 Common Stock 2023-11-20 4 S 0 2127 7.2415 D 103061 D Common Stock 1134.27 I By 401(k) Represents shares sold to satisfy tax withholding obligations upon the settlement of restricted stock units. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices between $7.24 and $7.2893. The reporting person undertakes to provide the Issuer, any security holder of the Company, 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 range set forth in this footnote. /s/ Larry Miller, Attorney-in-Fact for Molly Henderson 2023-11-21