As of early 2026, Mavacamten is a fully approved, first-in-class cardiac myosin inhibitor. It is widely authorized for use in over 50 countries across five continents. Its current regulatory and clinical status is summarized below:
1. Primary Approved Indication
Mavacamten is approved for the treatment of adults with symptomatic New York Heart Association (NYHA) class II-III hypertrophic obstructive cardiomyopathy (HOCM).
- Goal: To improve functional capacity, reduce left ventricular outflow tract (LVOT) obstruction, and alleviate symptoms like shortness of breath and fatigue.
2. Major Regulatory Milestones
- United States (FDA): Originally approved in April 2022. As of April 2025, the FDA updated the label to reduce echocardiography monitoring requirements, making the treatment slightly less burdensome for patients while maintaining safety.
- European Union (EMA): Approved in mid-2023. It remains an authorized therapy across the EU for adult HOCM.
- Global Reach: It has received approvals in major markets including Canada, Australia, Brazil, Switzerland, and China.
3. Recent Developments (January 2026)
- Adolescent Use: On January 12, 2026, positive Phase 3 results from the SCOUT-HCM trial has been announced. This study showed that mavacamten significantly reduced LVOT obstruction in adolescents (ages 12 to <18). While not yet fully approved for this age group, these results support an upcoming regulatory filing to expand the indication to younger patients.
- Market Competition: As of January 2026, mavacamten is no longer the only drug in its class. A second cardiac myosin inhibitor, Aficamten, received FDA approval in late December 2025, providing a new alternative for HOCM patients.
4. Safety and Monitoring (REMS)
Because Mavacamten works by reducing heart muscle contraction, it carries a risk of heart failure if the left ventricular ejection fraction (LVEF) drops too low.
- REMS Program: In the U.S., it is only available through the REMS (Risk Evaluation and Mitigation Strategy) program.
- Monitoring: Patients must undergo regular echocardiograms to monitor heart function and ensure the dosage is safe.
- Drug Interactions: Monitoring for interactions with CYP2C19 and CYP3A4 inhibitors/inducers is critical, as these can significantly affect the drug’s levels in the blood. CYP2C19: Cytochrome P450 family 2 subfamily C member 19. CYP2C19: Cytochrome P450 family 3 subfamily A member 4.