Mirum Pharmaceuticals SEC Filings

Insider transactions by a company director: Mirum Pharmaceuticals director Saira Ramasastry exercised a stock option and sold the resulting shares on 09/08/2025. The reporting shows an exercise (code M) of 17,000 shares at a conversion/exercise price of $23.51, followed the same day by a sale (code S) of 17,000 common shares at a weighted average sale price of $77.042178 (range: $76.835–$77.29). The derivative disclosure notes the option is fully vested. The Form 4 was signed by an attorney-in-fact on behalf of the reporting person.

Mirum Pharmaceuticals is registering 1,500,000 additional shares of common stock under its 2020 Inducement Plan, bringing the plan total to 5,500,000 shares. The additional shares were approved by the Compensation Committee and are the same class as shares previously registered under prior Form S-8 filings. The Registration Statement incorporates by reference specified prior annual, quarterly and current reports filed with the SEC and the companys Form 8-A description of common stock, and states subsequently filed reports under Sections 13, 14 or 15(d) will also be incorporated by reference.

Mirum Pharmaceuticals (MIRM) filed a Form 144 notifying a proposed sale of securities. The filing shows 17,000 common shares to be sold through Morgan Stanley Smith Barney on NASDAQ with an aggregate market value of $1,309,715.70 and total shares outstanding listed as 50,237,647. The securities were acquired and are proposed to be sold on 09/08/2025 via a stock option exercise, with cash payment recorded. The filer reports no securities sold in the past three months for the account. The notice includes the required representation that the seller is not aware of undisclosed material adverse information.

Frazier-affiliated investment vehicles amended a Schedule 13D for Mirum Pharmaceuticals (MIRM) to correct prior attributions and restate holdings. The filing shows Frazier Life Sciences IX, L.P. directly holds 3,566,912 shares (about 7.1% of 50,237,647 outstanding shares as of August 1, 2025). Related Frazier funds and vehicles report additional direct holdings: Frazier Life Sciences X (168,308 shares), Frazier Life Sciences XI (544,954 shares), Frazier Life Sciences Public Fund (1,574,374 shares) and Frazier Life Sciences Public Overage Fund (940,573 shares). Reporting clarifies that certain investment committee members are not attributed beneficial ownership and corrects prior overstatements. Individual reporting persons James N. Topper and Patrick J. Heron are shown with aggregate beneficial ownership positions reflecting the fund holdings and, for Heron, options that affect percentage calculations.

Janus Henderson Group plc reports beneficial ownership of Mirum Pharmaceuticals common stock totaling 5,236,277 shares, representing approximately 10.6% of the outstanding class. The filing shows the reporting entity holds no sole voting or dispositive power and reports shared voting and dispositive power over the stake. A listed subsidiary, JHIUS, is reported as beneficial owner of 5,140,740 shares (about 10.4%) with shared voting and dispositive authority. The filer certifies these securities are held in the ordinary course of business and not to change control of the issuer.

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.

Christopher Peetz, Mirum Pharmaceuticals CEO and director, reported related transactions on 08/11/2025 executed pursuant to a Rule 10b5-1 plan. He exercised 40,000 employee stock options with an exercise price of $2.936, resulting in an increase in directly held common stock to 178,641 shares. On the same date he sold 40,000 common shares at $62.00, reducing his direct holdings to 138,641 shares.

The filing also shows indirect beneficial ownership of 208,570 shares held by The Peetz Family Trust and that the exercised options are fully vested. All reported transactions were made under a 10b5-1 written plan adopted November 22, 2024.

Mirum Pharmaceuticals has filed a shelf registration providing a framework to offer common stock, preferred stock, debt securities and warrants, and includes a sales agreement to sell up to $200.0 million of common stock. The company commercializes three approved medicines—Livmarli (maralixibat), Cholbam (cholic acid) and Chenodal/Ctexli (chenodiol)—and markets these products in the U.S. and selected international territories through its specialized commercial team. Mirum has expanded its portfolio via an asset acquisition related to chenodiol and Cholbam and obtained worldwide rights to MRM-3379 through a license agreement to develop a Fragile-X treatment. The prospectus describes ongoing clinical programs for Livmarli and volixibat, regulatory designations for volixibat, and confirms Nasdaq listing under the symbol MIRM. The prospectus highlights inherent business risks and reserves broad discretion over use of proceeds, principally for general corporate purposes.

Mirum Pharmaceuticals, Inc. (MIRM) filed a Form 144 reporting the proposed sale of 40,000 common shares acquired by stock option exercise on 08/11/2025. The sale is to be executed through Morgan Stanley Smith Barney LLC with an aggregate market value of $2,480,000 based on the filing and the company has 50,237,647 shares outstanding as shown.

The filing also records a prior sale during the past three months: Christopher Peetz sold 40,000 shares on 08/07/2025 for $2,210,040. The filer certifies they have no undisclosed material adverse information and notes the securities were paid for in cash at acquisition.