Form 4: Mirum CMO Sells Shares After RSU Vesting

Mirum Pharmaceuticals' Chief Medical Officer, Joanne Quan, sold 7,287 shares of common stock to cover tax obligations following the vesting of 13,334 performance restricted stock units.

Summary

• Joanne Quan, Chief Medical Officer of Mirum Pharmaceuticals, Inc. (MIRM), reported changes in her beneficial ownership of company stock.
• On March 15, 2026, 13,334 performance restricted stock units (RSUs) vested, resulting in the acquisition of 13,334 shares of common stock.
• Following this vesting, Ms. Quan's direct beneficial ownership of common stock was 26,151 shares.
• On March 16, 2026, Ms. Quan sold 7,287 shares of common stock at a price of $91.9779 per share.
• The sale was conducted to cover tax withholding obligations associated with the vesting of the performance restricted stock units.
• After the sale, Ms. Quan's direct beneficial ownership of common stock stands at 18,864 shares.
• The vesting schedule for the RSUs is 2/3 of the shares on March 15, 2026, and 1/3 of the shares on March 15, 2027.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this filing as neutral. It reports a routine insider transaction related to executive compensation and tax obligations, which typically does not carry significant positive or negative implications for the company's operational or financial performance.

Positives

• The vesting of 13,334 performance restricted stock units indicates the achievement of performance milestones or tenure requirements by the Chief Medical Officer.

Negatives

• The sale of 7,287 shares by an insider, even for tax purposes, reduces the executive's direct equity stake in the company.

Future Outlook

The filing indicates a future vesting event for the remaining 1/3 of the performance restricted stock units on March 15, 2027, which will result in additional share acquisitions for the Chief Medical Officer.

Industry Context

StockSavvy.ai notes that transactions involving the vesting of restricted stock units and subsequent sales to cover tax obligations are a routine and common occurrence for executives receiving equity compensation in the biotechnology and pharmaceutical industries. This filing reflects a standard compensation event rather than a discretionary investment decision.

Comparison to Industry Standards

• The structure of performance restricted stock units and the practice of selling shares to cover tax withholding are standard components of executive compensation packages across publicly traded companies, particularly in high-growth sectors like pharmaceuticals.

Stakeholder Impact

• Shareholders may observe a slight reduction in the Chief Medical Officer's direct equity holdings, though this is a common practice for tax purposes related to equity compensation.

Next Steps

• The remaining 1/3 of the performance restricted stock units held by Joanne Quan are scheduled to vest on March 15, 2027.

Key Dates

Keywords

Mirum Pharmaceuticals, MIRM, Joanne Quan, Chief Medical Officer, Form 4, Insider Transaction, Restricted Stock Units, RSU Vesting, Stock Sale, Tax Withholding