X0306 4 2019-10-29 0 0001783183 Phathom Pharmaceuticals, Inc. PHAT 0001720320 Frazier Life Sciences IX, L.P. 601 UNION STREET SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001341382 Topper James N C/O PHATHOM PHARMACEUTICALS, INC. 2150 E. LAKE COOK ROAD, SUITE 800 BUFFALO GROVE IL 60089 1 0 1 0 0001365617 Heron Patrick J 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001782791 FHMLS IX, L.L.C. 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 0001782789 FHMLS IX, L.P. 601 UNION STREET, SUITE 3200 SEATTLE WA 98101 0 0 1 0 Common Stock 2019-10-29 4 C 0 1353640 15.20 A 6231638 D Common Stock 2019-10-29 4 P 0 1052631 19.00 A 7284269 D Convertible Promissory Notes 2019-10-29 4 C 0 20575342.48 D 2020-05-07 Common Stock 1353640 0 D Immediately prior to the closing of the Issuer's initial public offering, the outstanding principal and unpaid accrued interest due on the Convertible Promissory Notes automatically converted into shares of the Issuer's Common Stock based on a conversion price of $15.20 per share. The shares reported herein are held of record by Frazier Life Sciences IX, L.P. ("FLS IX"). The general partner of FLS IX is FHMLS IX, L.P., and the general partner of FHMLS IX, L.P. is FHMLS IX, L.L.C. James Topper and Patrick Heron are the sole managing members of FHMLS IX, L.L.C. and share voting and investment power of the securities held by FLS IX. Dr. Topper and Mr. Heron disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein. Frazier Life Sciences IX, L.P. By: FHMLS IX, L.P., its general partner By: FHMLS IX, L.L.C., its general partner By: /s/ James Topper Name: James Topper Title: Managing Member 2019-10-30 /s/ James Topper 2019-10-30 /s/ Patrick Heron 2019-10-30 FHMLS IX, L.L.C. By: /s/ James Topper Name: James Topper Title: Managing Member 2019-10-30 FHMLS IX, L.P., its general partner By: FHMLS IX, L.L.C., its general partner By: /s/ James Topper Name: James Topper Title: Managing Member 2019-10-30