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

Mirum Pharmaceuticals chief medical officer Joanne Quan reported routine equity compensation activity and a related stock sale.

Rhea-AI Filing Summary

Mirum Pharmaceuticals chief medical officer Joanne Quan reported routine equity compensation activity and a related stock sale. On January 21, 2026, 3,334 restricted stock units vested and were converted into the same number of Mirum common shares, increasing her directly held stake to 14,639 shares. The filing notes that each restricted stock unit represents a right to receive one share of common stock or its cash equivalent at the issuer’s discretion.

On January 22, 2026, Quan sold 1,822 shares of common stock at an average price of $93.3252 per share to cover tax withholding obligations tied to the vesting. After these transactions, she directly owned 12,817 shares of Mirum common stock and held 6,666 restricted stock units, which are scheduled to vest in equal thirds on each anniversary of January 21, 2025 until fully vested after three years.

Insider Trade Summary

Exercise and sale activity reported; no spread calculated

Exercise and Sale 3 txns

Insider Quan Joanne

Role CHIEF MEDICAL OFFICER

Sold 1,822 shs ($170K)

Approx. gross sale proceeds $170K

Approx. exercise cost $0.00

Type	Security	Shares	Price	Value
Sale	Common Stock	1,822	$93.3252	$170K
Exercise	Restricted Stock Units	3,334	$0.00	$0.00
Exercise	Common Stock	3,334	$0.00	$0.00

Holdings After Transaction: Restricted Stock Units — 6,666 contracts (Direct); Common Stock — 12,817 shares (Direct)

Footnotes (3)

1. F1. Each restricted stock unit represents a contingent right to receive one share of common stock (or its cash equivalent, at the discretion of the Issuer).
2. F2. Shares sold to cover tax withholding obligations associated with the vesting of restricted stock units.
3. F3. 1/3rd of the shares subject to the restricted stock units shall vest on each anniversary of January 21, 2025 (the "Vesting Commencement Date"), such that the entire award will be vested on the three-year anniversary of the Vesting Commencement Date.

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Accepted by SEC EDGAR 01/23/2026 - 05:30 PM Learn about SEC filing dates

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
Estimated average burden
hours per response:			0.5

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^*

Quan Joanne

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
01/21/2026

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	01/21/2026		M		3,334	A	(1)	14,639	D
Common Stock	01/22/2026		S(2)		1,822	D	$93.3252(1)	12,817	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 (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
Restricted Stock Units	(1)	01/21/2026		M			3,334	(3)	(3)	Common Stock	3,334	$0	6,666	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of common stock (or its cash equivalent, at the discretion of the Issuer).

2. Shares sold to cover tax withholding obligations associated with the vesting of restricted stock units.

3. 1/3rd of the shares subject to the restricted stock units shall vest on each anniversary of January 21, 2025 (the "Vesting Commencement Date"), such that the entire award will be vested on the three-year anniversary of the Vesting Commencement Date.

	/s/ Judit Ryvkin, Attorney-in-Fact	01/23/2026
	** 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.
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