Phathom Pharmaceuticals, Inc. — Director's Dealing 2025

Jun 5, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Phathom Pharmaceuticals, Inc. (PHAT)
CIK: 0001783183
Period of Report: 2025-06-03

Reporting Person: Topper James N (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-06-03	Common Stock	A	10500	—	Acquired	42596	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-06-03	Stock Option (Right to Buy)	$4.95	A	17500	Acquired	2035-06-02	Common Stock (17500)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	59403	Indirect
Common Stock	5827415	Indirect
Common Stock	1	Indirect
Common Stock	3912	Indirect

Footnotes

F1: The Restricted Stock Units ("RSUs") were granted on June 3, 2025, pursuant to the Issuer's Non-Employee Director Compensation Program. 100% of the total number of RSUs granted shall vest on the first to occur of (A) the first anniversary of the date of grant or (B) the next occurring annual meeting of the Issuer's stockholders, subject to the Reporting Person's continuing service on the Board through such vesting date. Each RSU represents a contingent right to receive one share of common stock of the Issuer.

F2: The shares reported herein are held of record by Frazier Life Sciences X, L.P. FHMLS X, L.P. is the general partner of Frazier Life Sciences X, L.P. and FHMLS X, L.L.C. is the general partner of FHMLS X, L.P. The Reporting Person is one of two managing members of FHMLS X, L.L.C. The Reporting Person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.

F3: The shares reported herein are held of record by Frazier Life Sciences IX, L.P. FHMLS IX, L.P. is the general partner of Frazier Life Sciences IX, L.P. and FHMLS IX, L.L.C. is the general partner of FHMLS IX, L.P. The Reporting Person is one of two managing members of FHMLS IX, L.L.C. The Reporting Person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.

F4: The shares reported herein are held of record by FHMLS IX, L.L.C. The Reporting Person is one of two managing members of FHMLS IX, L.L.C. The Reporting Person disclaims beneficial ownership of such securities except to the extent of his pecuniary interest therein.

F5: The Reporting Person is a manager of Topper Group III LLC and has voting and investment power of the securities held by Topper Group III LLC.

F6: The option was granted pursuant to the Issuer's Non-Employee Director Compensation Program. The option shall vest and/or become exercisable on the first to occur of (A) the firstanniversary of the date of grant or (B) the next occurring annual meeting of the Issuer's stockholders, subject to Reporting Person's continuing in service on the Board through such vestingdate.