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

Rhea-AI Filing Summary

Mirum Pharmaceuticals, Inc. (MIRM) – Form 4 insider transaction filing. SVP & Global Controller Jolanda Howe reported three transactions between 1–3 July 2025.

• 1 Jul 2025: 1,041 restricted stock units (RSUs) converted into an equal number of common shares (Transaction Code M). Post-conversion ownership temporarily rose to 3,467 shares.
• 2 Jul 2025: 564 shares sold at $48.25 (Code S) to cover tax-withholding obligations tied to the RSU vesting.
• 3 Jul 2025: 477 shares sold at $49.08 under a pre-existing Rule 10b5-1 plan adopted 16 Dec 2024.

Following these actions, Howe’s direct beneficial ownership declined from 3,467 to 2,426 common shares. All 1,041 RSUs from the reported award are now fully settled, leaving no outstanding derivative securities.

The RSU grant vests in three equal annual installments that began on 1 Jul 2023. All reported transactions were executed by a single insider; no joint filings were made.

Positive

• RSU conversion adds 1,041 shares to insider’s equity before sales, demonstrating continued participation in the company’s long-term incentive program.

Negative

• Full disposal of newly vested shares (1,041 in total) at an average of ~$48.64 reduces direct holdings to 2,426 shares.

Insights

Securities Analyst

TL;DR: Routine RSU vesting offset by tax-related and 10b5-1 sales; net ownership down to 2,426 shares—overall neutral signal.

The filing shows a standard RSU conversion (Code M) for 1,041 shares, immediately followed by sales that match the acquired amount. One sale covered withholding taxes, while the second was executed under a pre-scheduled Rule 10b5-1 plan, indicating no discretionary timing. Average sale price was roughly $48.64, providing an implied cash value of ~$50.7k. Because the insider retains 2,426 shares and the transactions appear administrative, the market impact is likely neutral. No information suggests strategic intent or changing outlook for MIRM.

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).

X

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^*

Howe Jolanda

(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)
	SVP, GLOBAL CONTROLLER

3. Date of Earliest Transaction (Month/Day/Year)
07/01/2025

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	07/01/2025		M		1,041	A	(1)	3,467	D
Common Stock	07/02/2025		S(2)		564	D	$48.25	2,903	D
Common Stock	07/03/2025		S(3)		477	D	$49.08	2,426	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)	07/01/2025		M			1,041	(4)	(4)	Common Stock	1,041	$0	0	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. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on December 16, 2024.

4. The restricted stock units vest in a series of three successive equal annual installments beginning July 1, 2023.

	/s/ Judit Ryvkin, Attorney-in-Fact	07/03/2025
	** 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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** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

Who conducted the transactions reported in Mirum Pharmaceuticals’ Form 4?

SVP & Global Controller Jolanda Howe was the sole reporting person.

How many shares were acquired through RSU vesting on July 1, 2025?

A total of 1,041 common shares were acquired via RSU conversion (Code M).

What prices were the insider sales executed at for MIRM stock?

Shares were sold at $48.25 on July 2 and $49.08 on July 3, 2025.

How many Mirum shares does the insider own after the reported transactions?

Post-transaction beneficial ownership stands at 2,426 common shares.

Were the sales discretionary or pre-planned?

The July 2 sale covered tax withholding; the July 3 sale was executed under a Rule 10b5-1 plan adopted on December 16, 2024.