SCHEDULE 13D/A

Mirum Pharmaceuticals Inc

Common Stock, par value $0.0001 per share · CUSIP: 604749101

Event date: 2026-01-23

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 IX, L.P.Reported CIK 0001720320

  Shares: 3,566,912.00 · Class: 5.9%

• FHMLS IX, L.P.Reported CIK 0001782789

  Shares: 3,566,912.00 · Class: 5.9%

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

  Shares: 3,566,912.00 · Class: 5.9%

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

  Shares: 459,010.00 · Class: 0.8%

• FHMLS X, L.P.Reported CIK 0001790880

  Shares: 459,010.00 · Class: 0.8%

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

  Shares: 459,010.00 · Class: 0.8%

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

  Shares: 2,514,947.00 · Class: 4.2%

• FHMLSP, L.P.Reported CIK 0001879466

  Shares: 2,514,947.00 · Class: 4.2%

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

  Shares: 2,514,947.00 · Class: 4.2%

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

  Shares: 1,075,884.00 · Class: 1.8%

• FHMLS XI, L.P.Reported CIK 0001911580

  Shares: 1,075,884.00 · Class: 1.8%

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

  Shares: 1,075,884.00 · Class: 1.8%

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

  Shares: 62,931.00 · Class: 0.1%

• FHMLS XII, L.P.Reported CIK 0002052246

  Shares: 62,931.00 · Class: 0.1%

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

  Shares: 62,931.00 · Class: 0.1%

• James N. TopperReported CIK 0001341382

  Shares: 4,025,922.00 · Class: 6.7%

• Patrick J. HeronReported CIK 0001365617

  Shares: 4,108,404.00 · Class: 6.8%

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