X0306 4 2020-03-17 0 0001783183 Phathom Pharmaceuticals, Inc. PHAT 0001734751 Stenhouse Mark C/O PHATHOM PHARMACEUTICALS, INC. 100 CAMPUS DRIVE, SUITE 102 FLORHAM PAK NJ 07932 1 0 0 0 Stock Option (Right to Buy) 29.84 2020-03-17 4 A 0 20000 0.00 A 2030-03-16 Common Stock 20000 20000 D The option will vest with respect to one-third of the shares of common stock on March 17, 2021, and will vest with respect to the remaining shares in equal monthly installments over the following two years, subject to the reporting person's continuous service to the Company on the applicable vesting dates. /s/ Larry Miller, Attorney-in-Fact for Mark Stenhouse 2020-03-19