Mirum Pharmaceuticals (NASDAQ: MIRM) director reports 10b5-1 sale

Rhea-AI Filing Summary

Mirum Pharmaceuticals director Saira Ramasastry reported an option exercise and share sale in Mirum Pharmaceuticals, Inc. common stock. On January 15, 2026, she exercised a stock option for 2,000 shares of common stock at an exercise price of $23.51 per share and acquired 2,000 shares directly. That same day, she sold 2,000 shares of common stock at a price of $90.99 per share, leaving her with 0 shares of common stock held directly after the transactions.

The filing shows that the underlying stock option is fully vested and that 8,000 stock options remained beneficially owned following the reported activity. The sale was made pursuant to a Rule 10b5-1 trading plan that she adopted on September 18, 2025, indicating the transactions were carried out under a pre-established, automatic 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
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).

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^*

Ramasastry Saira

(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
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
01/15/2026

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	01/15/2026		M		2,000	A	$23.51	2,000	D
Common Stock	01/15/2026		S(1)		2,000	D	$90.99	0	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
Stock Option (right to buy)	$23.51	01/15/2026		M			2,000	(2)	06/01/2032	Common Stock	2,000	$0	8,000	D

Explanation of Responses:

1. Reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on September 18, 2025.

2. The stock option is fully vested.

	/s/ Judit Ryvkin, Attorney-in-Fact	01/15/2026
	** 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).
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FAQ

What insider transaction did Mirum Pharmaceuticals (MIRM) director Saira Ramasastry report?

She reported exercising a stock option for 2,000 shares of Mirum Pharmaceuticals, Inc. common stock and selling 2,000 shares of common stock on January 15, 2026.

At what prices did Saira Ramasastry exercise and sell Mirum (MIRM) shares?

She exercised a stock option at an exercise price of $23.51 per share and sold 2,000 shares of common stock at a price of $90.99 per share.

How many Mirum Pharmaceuticals (MIRM) common shares did the director hold after the reported Form 4 transactions?

Following the reported transactions on January 15, 2026, she held 0 shares of Mirum Pharmaceuticals, Inc. common stock directly.

How many Mirum Pharmaceuticals (MIRM) stock options does the director still own after the transaction?

After the reported activity, she beneficially owned 8,000 stock options (stock options with a right to buy Mirum Pharmaceuticals, Inc. common stock).

Was the Mirum (MIRM) insider sale made under a Rule 10b5-1 trading plan?

Yes. The filing states the reported transaction occurred pursuant to a Rule 10b5-1 Plan adopted by the reporting person on September 18, 2025.

Is the Mirum Pharmaceuticals (MIRM) stock option held by the director fully vested?

Yes. A footnote to the filing explains that the stock option is fully vested.