Sec Form 4 Filing - BJERKHOLT ERIC @ Mirum Pharmaceuticals, Inc. - 2023-09-11

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person BJERKHOLT ERIC 2. Issuer Name and Ticker or Trading Symbol Mirum Pharmaceuticals, Inc. [ MIRM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) C/O MIRUM PHARMACEUTICALS, INC., 950 TOWER LANE, SUITE 1050 3. Date of Earliest Transaction (MM/DD/YY) 09/11/2023 (Street) FOSTER CITY, CA94404 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 09/11/2023 P 10,000 A $ 29.6492 ( 1 ) 10,000 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Stock Option (right to buy) $ 30.43 09/11/2023 A 110,000 ( 2 ) 09/10/2033 Common Stock 110,00 0 $ 0 110,000 D Restricted Stock Units ( 3 ) 09/11/2023 A 55,000 ( 4 ) ( 4 ) Common Stock 55,000 $ 0 55,000 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other BJERKHOLT ERIC C/O MIRUM PHARMACEUTICALS, INC. 950 TOWER LANE, SUITE 1050 FOSTER CITY, CA94404 Chief Financial Officer Signatures /s/ Judit Ryvkin, Attorney-in-Fact 09/12/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The price reported on this Form 4 is a weighted average price. The shares were purchased in multiple transactions ranging from $29.61 to $29.65, inclusive. The Reporting Person undertakes to provide 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 price within the range set forth herein. ( 2 )1/4th of the shares subject to the Option will vest one year after September 11, 2023 (the "Vesting Commencement Date") and the balance of the shares will vest in a series of 36 successive equal monthly installments measured from the first anniversary of the VestingCommencement Date. ( 3 )Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. ( 4 )The restricted stock units vest in a series of three successive equal annual installments beginning on the one year anniversary of September 11, 2023.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.