SCHEDULE: Frazier Funds Update Mirum Pharma Stake Post-Merger

Frazier Life Sciences Public Fund increased its beneficial ownership in Mirum Pharmaceuticals, Inc. following a merger with Frazier Life Sciences Public Overage Fund.

Summary

• Frazier Life Sciences Public Fund, L.P. (FLSPF) acquired 940,573 shares of Mirum Pharmaceuticals, Inc. Common Stock as a result of a merger with Frazier Life Sciences Public Overage Fund, L.P. (FLSPOF) on November 1, 2025.
• FLSPOF, FHMLSP Overage, L.P., and FHMLSP Overage, L.L.C. ceased to be reporting persons following the merger.
• Frazier Life Sciences IX, L.P. beneficially owns 3,566,912 shares, representing 7.1% of the class.
• Frazier Life Sciences X, L.P. beneficially owns 168,308 shares, representing 0.3% of the class.
• Frazier Life Sciences Public Fund, L.P. beneficially owns 2,514,947 shares, representing 5.0% of the class, which includes the shares acquired through the merger.
• Frazier Life Sciences XI, L.P. beneficially owns 544,954 shares, representing 1.1% of the class.
• James N. Topper beneficially owns 3,735,220 shares, representing 7.4% of the class, which includes shares held by Frazier Life Sciences IX, L.P. and Frazier Life Sciences X, L.P.
• Patrick J. Heron beneficially owns 3,735,220 shares, representing 7.6% of the class, which includes 5,703 shares held directly, 76,779 shares issuable upon option exercise, and shares held by Frazier Life Sciences IX, L.P. and Frazier Life Sciences X, L.P.
• The percentages of class represented are calculated based on 50,237,647 shares of Common Stock outstanding on August 1, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed on August 6, 2025.
• The source of funds for the purchase of shares by FLS IX, FLS X, FLSPF, and FLS XI was their respective working capital, with no borrowed funds used.

Sentiment

Score: 6

Explanation: The filing is largely neutral, detailing a change in beneficial ownership due to a fund merger. The consolidation of shares under one Frazier entity and continued significant overall stake by Frazier funds could be seen as a minor positive for stability and continued institutional interest, hence slightly above neutral.

Positives

• Increased beneficial ownership by Frazier Life Sciences Public Fund, L.P. through a merger, consolidating holdings and potentially streamlining investment management.
• Continued significant institutional ownership by Frazier Life Sciences funds, indicating ongoing investment interest and confidence in Mirum Pharmaceuticals, Inc.

Future Outlook

NA

Industry Context

This filing reflects a routine update in institutional ownership for a biotechnology company. Large investment funds like Frazier Life Sciences frequently adjust their stakes in life sciences companies, often consolidating holdings or rebalancing portfolios. The continued significant ownership by Frazier funds suggests ongoing confidence in Mirum Pharmaceuticals within the specialized life sciences investment sector.

Stakeholder Impact

• Shareholders: The consolidation of shares by Frazier Life Sciences Public Fund, L.P. could be viewed as a sign of continued institutional confidence, potentially offering some stability.
• Employees, Customers, Suppliers, Creditors: No direct impact is indicated by this ownership update.

Key Dates

Recommendation

This filing primarily details a restructuring of beneficial ownership among Frazier Life Sciences entities, rather than a new investment thesis or significant operational update for Mirum Pharmaceuticals. While the continued substantial stake by Frazier funds indicates ongoing confidence, the filing itself does not provide new information that would warrant a 'buy' or 'sell' recommendation. Investors should 'hold' and monitor future operational and financial reports from Mirum Pharmaceuticals for more actionable insights.

Keywords

Mirum Pharmaceuticals, Frazier Life Sciences, Schedule 13D, Beneficial Ownership, Institutional Investor, Biotechnology, Pharmaceuticals, Equity Stake, Merger, SEC Filing