Form 4: Mirum Pharmaceuticals Director Patrick Heron Reports Equity Transactions and Holdings

Mirum Pharmaceuticals, Inc. Director Patrick J. Heron filed a Form 4 detailing the acquisition of common stock through RSU conversion and the grant of new stock options and deferred stock units.

Summary

• Patrick J. Heron, a Director of Mirum Pharmaceuticals, Inc. (MIRM), reported changes in his beneficial ownership of company securities.
• On May 29, 2025, Mr. Heron acquired 5,703 shares of Mirum common stock through the conversion of Restricted Stock Units (RSUs).
• Following this transaction, Mr. Heron directly holds 5,703 shares of common stock.
• He also indirectly holds 3,566,912 shares of common stock through Frazier Life Sciences IX, L.P., and 168,672 shares through Frazier Life Sciences X, L.P., disclaiming beneficial ownership except to the extent of his pecuniary interest.
• On the same date, Mr. Heron was granted 6,268 stock options with an exercise price of $44, expiring on May 28, 2035.
• Additionally, he was granted 3,977 Deferred Stock Units (DSUs), each representing a contingent right to receive one share of common stock.
• The RSUs that converted were contingent rights to receive one share of common stock or its cash equivalent.
• The newly granted stock options and deferred stock units are scheduled to vest on the first anniversary of the grant date, or in any case, fully vest on the date of the Issuer's 2026 annual stockholder meeting.
• Vested deferred stock units will be paid out in common stock upon the earliest of a change in control of the Issuer or within 60 days following separation from service.

Sentiment

Score: 6

Explanation: The sentiment is slightly positive as it indicates a director receiving new equity awards and converting existing ones, aligning their interests with the company's long-term performance. This is a routine, non-negative event.

Positives

• Director Patrick J. Heron increased his direct common stock holdings by 5,703 shares through the conversion of Restricted Stock Units, indicating a conversion of previously granted equity awards.
• The grant of 6,268 new stock options and 3,977 Deferred Stock Units aligns the director's incentives with long-term company performance and shareholder value.

Future Outlook

The document indicates future vesting events for the newly granted stock options and deferred stock units, which are set to vest on the first anniversary of the grant date or, at the latest, by the Issuer's 2026 annual stockholder meeting. Deferred Stock Units will be paid out upon a change in control or separation from service.

Industry Context

This Form 4 filing is a routine disclosure of insider equity transactions, common across all publicly traded companies. It reflects standard compensation practices for directors, aligning their interests with long-term shareholder value through equity awards.

Related Party Transactions

• Patrick J. Heron's indirect beneficial ownership of 3,566,912 shares through Frazier Life Sciences IX, L.P. and 168,672 shares through Frazier Life Sciences X, L.P., where he is a managing member of the general partner, represents a common arrangement for directors associated with venture capital firms investing in the company.

Stakeholder Impact

• Shareholders: The director's increased direct ownership and new equity awards align his interests with shareholder value creation, potentially signaling confidence in the company's future.
• Employees: No direct impact mentioned, but general equity compensation practices can influence employee morale and retention.

Next Steps

• Vesting of 6,268 stock options on the first anniversary of the grant date or by the Issuer's 2026 annual stockholder meeting.
• Vesting of 3,977 Deferred Stock Units on the first anniversary of the grant date or by the Issuer's 2026 annual stockholder meeting.
• Potential payout of vested Deferred Stock Units upon a change in control of the Issuer or within 60 days following separation from service.

Key Dates

Keywords

Mirum Pharmaceuticals, MIRM, Form 4, Insider Trading, Beneficial Ownership, Stock Options, Restricted Stock Units, Deferred Stock Units, Director, Equity Compensation