Mirum Pharmaceuticals SEC Filings

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.

Jolanda Howe, SVP, Global Controller of Mirum Pharmaceuticals (MIRM), reported both non-derivative and derivative transactions affecting her holdings. The filing shows a sale of 10,000 common shares at $58.00, after which her reported direct beneficial ownership stood at 2,426 shares. On the same date she recorded an acquisition-related entry at a $6.27 price for 10,000 common shares, with a reported beneficial ownership figure of 12,426 shares following that transaction.

An employee stock option with a conversion/exercise price of $6.27 covering 10,000 underlying shares is reported and is stated to be fully vested. The filing notes the sale was executed pursuant to a Rule 10b5-1 plan adopted December 16, 2024, and the reporting person is shown as beneficial owner of 40,000 derivative securities following the reported activity.

Christopher Peetz, Mirum Pharmaceuticals (MIRM) Chief Executive Officer and director, reported option exercise and a planned sale of shares on 08/07/2025. He acquired 40,000 common shares by exercise at a conversion/exercise price of $2.936 per share, and concurrently sold 40,000 common shares under a Rule 10b5-1 plan at a weighted average price of $55.251 (range $55.25–$55.485). The filing notes the 10b5-1 plan was adopted on November 22, 2024, and the related employee stock option is fully vested.

The report lists direct beneficial ownership figures shown after the transactions (reported as 178,641 and 138,641 shares in the non-derivative table) and an indirect holding of 208,570 shares held by The Peetz Family Trust. The filing was submitted by an attorney-in-fact.