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

Rhea-AI Filing Summary

Eric Bjerkholt, Chief Financial Officer of Mirum Pharmaceuticals, sold 8,000 shares on 08/11/2025 at a weighted average price of $65.50 (range $65.31–$66.00) and on 08/12/2025 exercised employee stock options to acquire 2,954 shares at an exercise price of $26.49 per share. After these transactions the filing reports beneficial ownership of 31,190 shares. The filing notes 290 shares were acquired under the company Employee Stock Purchase Plan on May 10, 2025. The related option grant vests with one quarter after January 23, 2024 and the remainder in 36 equal monthly installments, and the form was signed by an attorney-in-fact.

Insights

Financial Analyst

TL;DR: CFO sale of 8,000 shares followed by exercise of 2,954 options; net change in holdings is modest and appears routine.

The filing shows a sale on 08/11/2025 and an option exercise on 08/12/2025. The weighted average sale price is disclosed at $65.50 with a price range of $65.31–$66.00, and the exercise price for the options is $26.49. Reported beneficial ownership after the transactions is 31,190 shares, which includes 290 shares from the Employee Stock Purchase Plan. Based solely on the disclosed figures, these are standard insider transactions combining liquidity with option conversion.

Corporate Governance Expert

TL;DR: Insider activity combines a stock sale and option exercise with a documented vesting schedule; disclosure appears complete on its face.

The Form 4 documents an 8,000-share sale and the exercise of 2,954 options, and it specifies the weighted average sale price and the option terms, including vesting mechanics. The filing also notes 290 ESPP shares are included in total holdings and provides the vesting timeline for the exercised options. From a governance perspective, the record includes required explanatory details and an attorney-in-fact signature, showing procedural compliance in the disclosure itself.

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

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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^*

BJERKHOLT ERIC

(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 FINANCIAL OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2025

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	08/11/2025		S		8,000	D	(1)	28,236(2)	D
Common Stock	08/12/2025		M		2,954	A	$26.49	31,190	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
Employee Stock Option (right to buy)	$26.49	08/12/2025		M			2,954	(3)	01/22/2034	Common Stock	2,954	$0	29,046	D

Explanation of Responses:

1. The weighted average sale price for the transaction reported was $65.50, and the range of prices were between $65.31 and $66.00. Upon request by the SEC staff, the Issuer, or any security holder of the Issuer, full information regarding the number of shares sold at each separate price will be provided.

2. Includes 290 shares of Common Stock that were acquired by the Reporting Person on May 10, 2025 pursuant to the Issuer's Employee Stock Purchase Plan.

3. 1/4th of the shares vested one year after January 23, 2024 (the "Vesting Commencement Date") and the balance of the shares vest in a series of 36 successive equal monthly installments measured from the first anniversary of the Vesting Commencement Date.

	/s/ Judit Ryvkin, Attorney-in-Fact	08/12/2025
	** 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).
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FAQ

What insider transactions did Mirum Pharmaceuticals (MIRM) report?

The Form 4 reports a sale of 8,000 shares on 08/11/2025 and an exercise to acquire 2,954 shares on 08/12/2025.

At what price were the 8,000 shares sold by the CFO (MIRM)?

The weighted average sale price was $65.50, with a range of $65.31–$66.00.

What was the exercise price for the options exercised by the CFO (MIRM)?

The exercise price for the exercised options was $26.49 per share.

How many shares does the reporting person beneficially own after the transactions?

The filing reports beneficial ownership of 31,190 shares following the reported transactions.

Does the filing disclose any ESPP or vesting details for the reporting person?

Yes. It includes 290 shares acquired via the Employee Stock Purchase Plan on May 10, 2025, and notes the option vests one quarter after January 23, 2024 with the balance vesting in 36 equal monthly installments.