13D Filings
MIRUM PHARMACEUTICALS, INC.
MIRM
Amendment
Ownership

7.60%

Total Shares

3,735,220

Issuer CIK

1759425

CUSIP

604749101

Event Date

Aug 17, 2025

Accepted

Aug 20, 2025, 05:17 PM

Reporting Persons (20)
Joint Filing

This is a joint filing. The reported shares may overlap between reporting persons and should not be summed.

NameType% of ClassAggregateSole VotingShared Voting
Patrick J. Heron
Individual
7.60%3,735,22082,4823,735,220
James N. Topper
Individual
7.40%3,735,22003,735,220
Frazier Life Sciences IX, L.P.
Partnership
7.10%3,566,91203,566,912
FHMLS IX, L.P.
Partnership
7.10%3,566,91203,566,912
FHMLS IX, L.L.C.
Other
7.10%3,566,91203,566,912
FHMLSP, L.P.
Partnership
3.10%1,574,37401,574,374
Frazier Life Sciences Public Fund, L.P.
Partnership
3.10%1,574,37401,574,374
FHMLSP, L.L.C.
Other
3.10%1,574,37401,574,374
FHMLSP Overage, L.P.
Partnership
1.90%940,5730940,573
Frazier Life Sciences Public Overage Fund, L.P.
Partnership
1.90%940,5730940,573
FHMLSP Overage, L.L.C.
Other
1.90%940,5730940,573
FHMLS XI, L.L.C.
Other
1.10%544,9540544,954
Frazier Life Sciences XI, L.P.
Partnership
1.10%544,9540544,954
FHMLS XI, L.P.
Partnership
1.10%544,9540544,954
FHMLS X, L.L.C.
Other
0.30%168,3080168,308
FHMLS X, L.P.
Partnership
0.30%168,3080168,308
Frazier Life Sciences X, L.P.
Partnership
0.30%168,3080168,308
Albert Cha
Individual
0.00%000
James Brush
Individual
0.00%000
Daniel Estes
Individual
0.00%000
Disclosure Items (3)

Security Title

Common Stock, par value $0.0001 per share

Issuer Name

MIRUM PHARMACEUTICALS, INC.

Issuer Address

989 E Hillsdale Blvd., Suite 300, FOSTER CITY, CA, 94404

The information contained in Rows 7, 8, 9, 10, 11, and 13 of each Reporting Person's cover page to this Schedule 13D (including the footnotes thereto) is incorporated by reference into this Item 5. FLSPF directly holds 1,574,374 shares of Common Stock of the Issuer (the "FLSPF Shares"). FHMLSP, L.P. is the general partner of FLSPF and the general partner of FHMLSP, L.P. is FHMLSP, L.L.C., which is managed by an investment committee of four that acts by majority vote. Accordingly, no members of such committee are attributed beneficial ownership of the securities directly held by FLSPF, and this Schedule 13D corrects any previous attribution to, and overstatement of beneficial ownership by, such members as reflected in any prior Statements. FLSPOF directly holds 940,573 shares of Common Stock of the Issuer (the "FLSPOF Shares"). FHMLSP Overage, L.P. is the general partner of FLSPOF and the general partner of FHMLSP Overage, L.P. is FHMLSP Overage, L.L.C., which is managed by an investment committee of four that acts by majority vote. Accordingly, no members of such committee are attributed beneficial ownership of the securities directly held by FLSPOF, and this Schedule 13D corrects any previous attribution to, and overstatement of beneficial ownership by, such members as reflected in any prior Statements. FLS IX directly holds 3,566,912 shares of Common Stock of the Issuer (the "FLS IX Shares"). FHMLS IX, L.P. is the general partner of FLS IX and FHMLS IX, L.L.C. is the general partner of FHMLS IX, L.P. Heron and Topper are the members of FHMLS IX, L.L.C. and therefore share voting and investment power over the FLS IX Shares. FLS X directly holds 168,308 shares of Common Stock of the Issuer (the "FLS X Shares"). FHMLS X, L.P. is the general partner of FLS X and FHMLS X, L.L.C. is the general partner of FHMLS X, L.P. Heron and Topper are the members of FHMLS X, L.L.C. and therefore share voting and investment power over the FLS X Shares. FLS XI directly holds 544,954 shares of Common Stock of the Issuer (the "FLS XI Shares"). FHMLS XI, L.P. is the general partner of FLS XI and the general partner of FHMLS XI, L.P. is FHMLS XI, L.L.C., which is managed by an investment committee of three that acts by majority vote. Accordingly, no members of such committee are attributed beneficial ownership of the securities directly held by FLS XI, and this Schedule 13D corrects any previous attribution to, and overstatement of beneficial ownership by, such members as reflected in any prior Statements. Except as specifically stated herein, the filing of this Schedule 13D shall not be construed as an admission that any Reporting Person or any of the foregoing is, for the purposes of Section 13(d) and/or Section 13(g) of the Act or otherwise, the beneficial owner of any securities covered by this Schedule 13D or a member of a "group" with any other person.

Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit A to Schedule 13D/A filed on September 5, 2023)

MIRUM PHARMACEUTICALS, INC. — Schedule 13D | 13D Filings