[Form 4] Mirum Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Mirum Pharmaceuticals, Inc. (MIRM) reported an insider equity transaction by its Chief Executive Officer, who is also a director. On 11/18/2025, the reporting person exercised an employee stock option to buy 19,133 shares of common stock at an exercise price of $19.24 per share, coded as transaction type "M" for an option exercise.

Following this transaction, the reporting person beneficially owns 158,034 shares of Mirum common stock directly and 208,570 shares indirectly through The Peetz Family Trust. The filing notes that the stock option involved in this transaction is fully vested and that the direct holdings include 260 shares acquired on November 10, 2025 under the company’s Employee Stock Purchase Plan.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Peetz Christopher

(Last) (First) (Middle)

C/O MIRUM PHARMACEUTICALS, INC.

989 E HILLSDALE BLVD., SUITE 300

(Street)

FOSTER CITY CA 94404

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Mirum Pharmaceuticals, Inc. [ MIRM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF EXECUTIVE OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
11/18/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	11/18/2025		M		19,133	A	$19.24	158,034(1)	D
Common Stock								208,570	I	By The Peetz Family Trust

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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
Employee Stock Option (right to buy)	$19.24	11/18/2025		M			19,133	(2)	01/09/2030	Common Stock	19,133	$0	150,867	D

Explanation of Responses:

1. Includes 260 shares of Common Stock that were acquired by the Reporting Person on November 10, 2025, pursuant to the Issuer's Employee Stock Purchase Plan.

2. The stock option is fully vested.

	/s/ Judit Ryvkin, Attorney-in-Fact	11/19/2025
	** Signature of Reporting Person	Date
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.

FAQ

What insider transaction was reported for Mirum Pharmaceuticals (MIRM)?

The Chief Executive Officer and director of Mirum Pharmaceuticals (MIRM) exercised an employee stock option on 11/18/2025 to acquire 19,133 shares of common stock at an exercise price of $19.24 per share, reported as transaction code "M".

How many Mirum Pharmaceuticals (MIRM) shares does the insider own after the transaction?

After the reported transaction, the insider beneficially owns 158,034 shares of Mirum common stock directly and 208,570 shares indirectly through The Peetz Family Trust.

What type of derivative security was involved in the Mirum (MIRM) Form 4 filing?

The filing involves an employee stock option (right to buy) with an exercise price of $19.24, covering 19,133 shares of Mirum common stock. The option is stated to be fully vested and has an expiration date of 01/09/2030.

Did the Mirum Pharmaceuticals (MIRM) insider acquire any shares through an employee stock purchase plan?

Yes. The explanation notes that the insider’s direct holdings include 260 shares of common stock acquired on November 10, 2025 under Mirum’s Employee Stock Purchase Plan.

What is the relationship of the reporting person to Mirum Pharmaceuticals (MIRM)?

The reporting person is both a director and an officer of Mirum Pharmaceuticals, serving as the company’s Chief Executive Officer.

How is indirect ownership reported in this Mirum (MIRM) Form 4?

Indirect ownership is reported as 208,570 shares of Mirum common stock held by The Peetz Family Trust, with the insider listed as having indirect beneficial ownership of these shares.