X0306 4 2023-03-01 0 0001783183 Phathom Pharmaceuticals, Inc. PHAT 0001690298 Curran Terrie C/O PHATHOM PHARMACEUTICALS, INC. 100 CAMPUS DRIVE, SUITE 102 FLORHAM PARK NJ 07932 1 1 0 0 President and Chief Executive Common Stock 2023-03-01 4 S 0 1436 8.5411 D 175371 D Common Stock 2235.9 I by 401(k) The sale reported on this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 26, 2022. 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 ranging from $8.53 to $8.7614. 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 Terrie Curran 2023-03-03