Frazier Life Sciences IX, L.P. - 23 Jan 2026 SCHEDULE 13D/A Report for MIRUM PHARMACEUTICALS, INC. Common Stock, par value $0.0001 per share (MIRM)

Filing manager
Frazier Life Sciences IX, L.P.
Reporting owner
Patrick J. Heron
Security
MIRUM PHARMACEUTICALS, INC. Common Stock, par value $0.0001 per share
Beneficially owned shares
4,108,404 shares
Ownership signal CIK-linked ownership evidence from parsed SEC filings. 2 signals
Large-stake signal

Form

SCHEDULE 13D/A

Active or control-oriented beneficial ownership filing.

Ownership

6.8%

Beneficial ownership of this reported class.

Shares

4,108,404 shares

Shares beneficially owned as disclosed.

Event date

23 Jan 2026

Date tied to the ownership event or amendment.

Accepted by SEC

27 Jan 2026

EDGAR acceptance date.

How to read this large-stake filing
  • Schedule 13D/G filings focus on beneficial ownership stakes, not a full portfolio.
  • Compare this filing with the holder history and issuer page before treating the percentage as a current position.
  • Use amendments to understand whether the disclosed stake increased, decreased, or changed reporting status.
Class ownership
6.8%
Subject security Names, identifiers, and filing context for this profile. 2 source fields
Symbol
MIRM
Shares outstanding
60,417,706 shares
Source evidence Original filing metadata and source links for verification. 5 source fields
SEC form
SCHEDULE 13D/A
Accepted by SEC
27 Jan 2026, 16:12:31 UTC
Event date
23 Jan 2026
Prior SEC filing
04 Nov 2025
Source filing
View source filing

Key filing fact

Frazier Life Sciences IX, L.P. disclosed 6.8% ownership in MIRUM PHARMACEUTICALS, INC. Common Stock, par value $0.0001 per share (MIRM) on 23 Jan 2026.

Key facts

  • Frazier Life Sciences IX, L.P. filed SCHEDULE 13D/A for MIRUM PHARMACEUTICALS, INC. Common Stock, par value $0.0001 per share (MIRM).
  • Disclosed ownership: 6.8%.
  • Date of event: 23 Jan 2026.

Change

  • Previous schedule filing date: 04 Nov 2025.
  • Current filing was accepted on 27 Jan 2026, 16:12.

Research use

  • This page turns one Schedule 13D/G filing into a quick large-stake read before the raw reporting-person rows.
  • Use the linked SEC filing as the source of truth for ownership percentages, shares, and reporting-party details.

Evidence

Backed by Schedule 13D/13G

Beneficial ownership values are sourced from the original SEC Schedule 13D/13G filing.

View source filing

Reporting persons

Disclosed reporting parties (17)

Names, ownership percentages, voting power, signatures, titles, and CIKs as disclosed in this Schedule 13D/G filing.

Name Ownership Shares owned Sole voting power Shared voting power Signature Title CIK
Frazier Life Sciences IX, L.P. 5.9% 3,566,912 0 3,566,912 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS IX, L.L.C., GP of FHMLS IX, L.P., GP of Frazier Life Sciences IX, L.P. 0001720320
FHMLS IX, L.P. 5.9% 3,566,912 0 3,566,912 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS IX, L.L.C., GP of FHMLS IX, L.P. 0001782789
FHMLS IX, L.L.C. 5.9% 3,566,912 0 3,566,912 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS IX, L.L.C. 0001782791
Frazier Life Sciences X, L.P. 0.8% 459,010 0 459,010 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P., GP of Frazier Life Sciences X, L.P. 0001790879
FHMLS X, L.P. 0.8% 459,010 0 459,010 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P. 0001790880
FHMLS X, L.L.C. 0.8% 459,010 0 459,010 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS X, L.L.C. 0001790811
Frazier Life Sciences Public Fund, L.P. 4.2% 2,514,947 0 2,514,947 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P., GP of Frazier Life Sciences Public Fund, L.P. 0001863769
FHMLSP, L.P. 4.2% 2,514,947 0 2,514,947 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLSP, L.L.C., GP of FHMLSP, L.P. 0001879466
FHMLSP, L.L.C. 4.2% 2,514,947 0 2,514,947 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLSP, L.L.C. 0001879465
Frazier Life Sciences XI, L.P. 1.8% 1,075,884 0 1,075,884 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P., GP of Frazier Life Sciences XI, L.P. 0001911592
FHMLS XI, L.P. 1.8% 1,075,884 0 1,075,884 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS XI, L.L.C., GP of FHMLS XI, L.P. 0001911580
FHMLS XI, L.L.C. 1.8% 1,075,884 0 1,075,884 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS XI, L.L.C. 0001911623
Frazier Life Sciences XII, L.P. 0.1% 62,931 0 62,931 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS XII, L.L.C., GP of FHMLS XII, L.P., GP of Frazier Life Sciences XII, L.P. 0002052255
FHMLS XII, L.P. 0.1% 62,931 0 62,931 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS XII, L.L.C., GP of FHMLS XII, L.P. 0002052246
FHMLS XII, L.L.C. 0.1% 62,931 0 62,931 /s/ Jennifer Martin By Jennifer Martin, CFO of FHMLS XII, L.L.C. 0002052177
James N. Topper 6.7% 4,025,922 0 4,025,922 /s/ Jennifer Martin By Jennifer Martin, Attorney-in-Fact for Patrick J. Heron, pursuant to Power of Attorney 0001341382
Patrick J. Heron 6.8% 4,108,404 82,482 4,025,922 /s/ Jennifer Martin By Jennifer Martin, Attorney-in-Fact for Patrick J. Heron, pursuant to Power of Attorney 0001365617
We use cookies and similar technologies to provide certain features, enhance the user experience and, if you allow them, measure engagement and deliver advertising. Analytics and marketing storage stay off until you grant consent. By clicking on "Agree and continue", you declare your consent to the use of the selected optional cookies. Manage preferences to update or revoke optional consent for future visits. For more information, see our Privacy Policy .