SCHEDULE 13D/A

Phathom Pharmaceuticals Inc

Common Stock, $0.0001 par value per share · CUSIP: 71722W107

Event date: 2025-11-01

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Frazier Life Sciences Public Fund, L.P.Reported CIK 0001863769

  Shares: 5,323,356.00 · Class: 7.5%

• FHMLSP, L.P.Reported CIK 0001879466

  Shares: 5,323,356.00 · Class: 7.5%

• FHMLSP, L.L.C.Reported CIK 0001879465

  Shares: 5,323,356.00 · Class: 7.5%

• Frazier Life Sciences X, L.P.Reported CIK 0001790879

  Shares: 59,403.00 · Class: 0.1%

• FHMLS X, L.P.Reported CIK 0001790880

  Shares: 59,403.00 · Class: 0.1%

• FHMLS X, L.L.C.Reported CIK 0001790811

  Shares: 59,403.00 · Class: 0.1%

• Frazier Life Sciences XI, L.P.Reported CIK 0001911592

  Shares: 980,286.00 · Class: 1.4%

• FHMLS XI, L.P.Reported CIK 0001911580

  Shares: 980,286.00 · Class: 1.4%

• FHMLS XI, L.L.C.Reported CIK 0001911623

  Shares: 980,286.00 · Class: 1.4%

• Frazier Life Sciences IX, L.P.Reported CIK 0001720320

  Shares: 5,827,415.00 · Class: 8.2%

• FHMLS IX, L.P.Reported CIK 0001782789

  Shares: 5,827,415.00 · Class: 8.2%

• FHMLS IX, L.L.C.Reported CIK 0001782791

  Shares: 5,827,416.00 · Class: 8.2%

• Frazier Life Sciences XII, L.P.Reported CIK 0002052255

  Shares: 276,029.00 · Class: 0.4%

• FHMLS XII, L.P.Reported CIK 0002052246

  Shares: 276,029.00 · Class: 0.4%

• FHMLS XII, L.L.C.Reported CIK 0002052177

  Shares: 276,029.00 · Class: 0.4%

• James N. TopperReported CIK 0001341382

  Shares: 5,985,327.00 · Class: 8.6%

• Patrick J. HeronReported CIK 0001365617

  Shares: 5,901,756.00 · Class: 8.4%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.