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

Rhea-AI Filing Summary

Mirum Pharmaceuticals chief executive Christopher Peetz reported routine equity activity involving company stock. On January 23, 2026, he exercised 12,500 restricted stock units, each converting into one share of common stock at an exercise price of $0, increasing his direct holdings to 176,233 shares.

On January 26, 2026, Peetz sold 6,831 shares of common stock at $96.192 per share, with the filing stating these shares were sold to cover tax withholding tied to the RSU vesting. After the sale, he directly owned 169,402 shares and also beneficially owned 187,500 shares indirectly through The Peetz Family Trust.

Insider Trade Summary

Net Seller: 6,831 shares ($657,088)

Net Sell 4 txns

Insider Peetz Christopher

Role CHIEF EXECUTIVE OFFICER

Sold 6,831 shs ($657K)

Type	Security	Shares	Price	Value
Sale	Common Stock	6,831	$96.192	$657K
Exercise	Restricted Stock Units	12,500	$0.00	--
Exercise	Common Stock	12,500	$0.00	--
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 169,402 shares (Direct); Restricted Stock Units — 12,500 shares (Direct); Common Stock — 187,500 shares (Indirect, By The Peetz Family Trust)

Footnotes (1)

1. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. Shares sold to cover tax withholding obligations associated with the vesting of restricted stock units. 1/3rd of the shares subject to the restricted stock units shall vest on each anniversary of January 23, 2024 (the "Vesting Commencement Date"), such that the entire award will be vested on the three-year anniversary of the Vesting Commencement Date.

Form 4 Insider Transactions: What Each Field Means →

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)
01/23/2026

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	01/23/2026		M		12,500	A	(1)	176,233	D
Common Stock	01/26/2026		S(2)		6,831	D	$96.192	169,402	D
Common Stock								187,500	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
Restricted Stock Units	(1)	01/23/2026		M			12,500	(3)	(3)	Common Stock	12,500	$0	12,500	D

Explanation of Responses:

1. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock.

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 23, 2024 (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	01/27/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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