X0508 4 2023-11-01 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 2023-11-01 4 A 0 22500 0.00 A 117680 D Common Stock 2023-11-01 4 S 0 811 7.80 D 116869 D Common Stock 2023-11-01 4 S 0 11681 8.95 D 105188 D Common Stock 1134.27 I By 401(k) Represents shares earned with respect to a performance stock unit award granted on January 19, 2023 that contained a performance-vesting requirement that was satisfied on November 1, 2023. Represents shares sold to satisfy tax withholding obligations upon the settlement of performance stock units. /s/ Larry Miller, Attorney-in-Fact for Molly Henderson 2023-11-03