X0508 4 2025-04-03 0001783183 Phathom Pharmaceuticals, Inc. PHAT 0001417397 Basta Steven L C/O PHATHOM PHARMACEUTICALS, INC. 100 CAMPUS DRIVE, SUITE 102 FLORHAM PARK 07932 true true false false President and CEO false Performance Shares 2025-04-03 4 A false 360000 0 A Common Stock 360000 360000 D Stock Option (Right to Buy) 5.01 2025-04-03 4 A false 1085000 0 A 2035-04-02 Common Stock 1085000 1085000 D Each performance stock unit represents a contingent right to receive one share of common stock of the Issuer. The performance stock units will vest based on the achievement of stock price hurdles and service-based vesting requirements over a period of four years following the grant date. The stock option will vest with respect to 25% of the shares of common stock on April 3, 2026, and will vest with respect to the remaining shares in equal monthly installments over the following three years, subject to the reporting person's continuous service to the Company on the applicable vesting dates. /s/ Molly Henderson, Attorney-in-Fact for Steven L. Basta 2025-04-03