Bristol Myers Squibb has moved closer to expanding the use of its heart disease therapy Camzyos® (mavacamten) after the U.S. Food and Drug Administration (FDA) accepted a supplemental New Drug Application (sNDA) seeking approval of the drug for adolescents aged 12 years to under 18 years with symptomatic obstructive hypertrophic cardiomyopathy (oHCM).
The FDA has granted the application Priority Review, signaling the agency’s view that the therapy could provide a significant advancement in treatment options for a serious condition. A regulatory decision is expected by September 30, 2026, under the Prescription Drug User Fee Act (PDUFA) timeline.
If approved, Camzyos would become the first cardiac myosin inhibitor specifically authorized for adolescents with symptomatic oHCM, potentially addressing a significant unmet medical need in a younger patient population.
Obstructive hypertrophic cardiomyopathy is a chronic genetic heart disorder characterized by abnormal thickening of the heart muscle, which can obstruct blood flow from the heart. The condition can lead to symptoms such as shortness of breath, chest pain, fatigue, dizziness, and fainting. In adolescents, the disease can affect physical activity, participation in sports, and overall quality of life during critical developmental years.
Camzyos is currently approved in the United States for adults with symptomatic New York Heart Association (NYHA) Class II and III oHCM. The therapy works by targeting cardiac myosin, a protein involved in heart muscle contraction, helping to reduce excessive contractility and improve blood flow. According to Bristol Myers Squibb, nearly 25,000 patients in the United States have been prescribed Camzyos by more than 4,500 healthcare providers since its launch.
The company’s application for adolescent use is supported by results from the Phase III SCOUT-HCM clinical trial, which evaluated the efficacy and safety of Camzyos in adolescents with symptomatic oHCM. The study successfully met its primary endpoint, demonstrating a statistically significant and clinically meaningful reduction in Valsalva left ventricular outflow tract (LVOT) gradient at Week 28 compared with placebo.
Reduction in LVOT gradient is an important treatment goal in oHCM because it reflects improved blood flow from the heart and can correlate with symptom relief and enhanced exercise capacity.
The safety findings from the study were also encouraging. Bristol Myers Squibb reported that the safety profile observed in adolescents was consistent with that seen in adult patients. Notably, no participants experienced a reduction in left ventricular ejection fraction below 50%, a key measure of heart pumping function that is closely monitored in patients receiving the therapy.
Results from the 28-week placebo-controlled portion of the SCOUT-HCM study were presented at the 2026 American College of Cardiology Annual Scientific Session and simultaneously published in The New England Journal of Medicine, highlighting the significance of the findings within the cardiology community.
The SCOUT-HCM trial enrolled 44 patients between the ages of 12 and 18 years with symptomatic oHCM across multiple international sites. The study includes three treatment phases spanning up to 200 weeks, including a placebo-controlled period, an active-treatment crossover phase, and a long-term open-label extension designed to evaluate durability of benefit and long-term safety.
Cristian Massacesi, Executive Vice President, Chief Medical Officer and Head of Development at Bristol Myers Squibb, said the FDA’s acceptance of the application offers the possibility of extending innovative treatment options to younger patients who currently have limited therapeutic choices. He noted that oHCM can significantly affect both the physical and emotional well-being of adolescents, making new treatment approaches particularly important.
The Priority Review designation underscores the potential clinical importance of the therapy and places Camzyos on track to potentially become the first targeted cardiac myosin inhibitor available for adolescents with symptomatic obstructive hypertrophic cardiomyopathy. If approved, the drug could mark a significant advancement in the management of this rare but serious heart condition in younger patients.