Phathom Pharmaceuticals, Inc. — Director's Dealing 2025

May 13, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Phathom Pharmaceuticals, Inc. (PHAT)
CIK: 0001783183
Period of Report: 2025-05-09

Reporting Person: Topper James N (N/A)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-05-09	Common Stock	P	33376	$3.1928	Acquired	33376	Indirect
2025-05-09	Common Stock	P	2226	$3.6177	Acquired	35602	Indirect
2025-05-12	Common Stock	P	12601	$3.0395	Acquired	48203	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	5827415	Indirect
Common Stock	1	Indirect
Common Stock	32096	Direct
Common Stock	3912	Indirect

Footnotes

F1: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.575 to $3.57, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (1) to this Form 4.

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 price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.58 to $3.75, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (3) to this Form 4.

F4: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.825 to $3.15, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote (4) to this Form 4

F5: 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.

F6: 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.

F7: 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.