Mirum Pharmaceuticals Appoints New Chief Medical Officer

What Happened Mirum Pharmaceuticals, Inc. filed an 8‑K reporting that its Board appointed Rob Myers, M.D., to succeed Joanne Quan, M.D., as Chief Medical Officer. The board made the appointment on September 2, 2026; Dr. Myers’ employment is expected to begin September 21, 2026. Dr. Quan ceased serving as CMO effective September 2, 2026, and her employment termination is expected to occur on October 19, 2026 (the “Separation Date”).

Key Details

• Appointment announced in the 8‑K dated September 8, 2026; Dr. Myers expected to start Sept 21, 2026.
• Dr. Quan stopped serving as CMO on Sept 2, 2026; her employment is expected to end Oct 19, 2026.
• Compensation Committee approved extending Dr. Quan’s post‑termination stock option exercise period to 12 months after the Separation Date.
• The committee also approved payment on the Separation Date of Dr. Quan’s 2026 annual target bonus at 100% achievement, subject to customary conditions and a final Separation Agreement; severance benefits expected under the company’s Severance Plan if separation qualifies as involuntary.

Why It Matters A change in the Chief Medical Officer is material because the CMO plays a central role in clinical development, regulatory strategy, and medical affairs—areas investors watch closely for biotech companies. The filing also signals there may be one‑time costs or payouts (severance, bonus payment, and extended option exercise rights) tied to Dr. Quan’s departure; the company will file the final Separation Agreement in a forthcoming Form 10‑Q or Form 10‑K with full terms. The 8‑K includes forward‑looking statements about timing and final terms, so investors should look for the forthcoming filing for complete details.