X0508 4/A 2023-07-14 2023-07-17 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 2023-07-14 4 A 0 25000 0.00 A 95180 D Represents restricted stock units ("RSUs") granted on July 14, 2023. One third (1/3) of the total number of RSUs granted vest on each of the first three anniversaries of July 14, 2023, the vesting commencement date, subject to the Reporting Person's continued service on the applicable vesting date. Each RSU represents a contingent right to receive one share of common stock of the Issuer. This amendment is being filed to correct the transaction price included in the Form 4 filed on behalf of the Reporting Person on July 17, 2023. Includes 1,674 shares acquired under the Phathom Pharmaceuticals, Inc. employee stock purchase plan in July 2023. /s/ Larry Miller, Attorney-in-Fact for Molly Henderson 2023-07-21