PRINCETON, New Jersey, September 30, 2026

Bristol Myers Squibb announced that the U.S. Food and Drug Administration (FDA) has approved an expanded indication for CAMZYOS® (mavacamten) to treat symptomatic obstructive hypertrophic cardiomyopathy (oHCM) and improve functional capacity and symptoms in adults and pediatric patients weighing at least 30 kg (66 pounds). The expanded U.S. indication makes CAMZYOS the only FDA-approved therapy for pediatric patients with symptomatic oHCM, according to the company and FDA. The approval is based on results from the Phase 3 SCOUT-HCM trial, extending the clinical use of the cardiac myosin inhibitor beyond adults, for whom CAMZYOS was initially approved in the United States in 2022.

FDA Approval Expands CAMZYOS to Pediatric Patients

The FDA approval covers pediatric patients with symptomatic oHCM who weigh 30 kg or more, providing a specifically approved pharmacological treatment option for this younger population. Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disorder characterized by abnormal thickening of the heart muscle, while the obstructive form can restrict blood flow from the left ventricle through the left ventricular outflow tract (LVOT). Pediatric patients with obstructive disease may experience substantial cardiovascular complications, including heart failure, ventricular arrhythmias and atrial fibrillation. Before this expanded indication, management of pediatric oHCM could include beta blockers, calcium channel blockers, disopyramide and, in selected cases, invasive septal reduction procedures. The FDA described CAMZYOS as the first treatment approved for children with symptomatic oHCM to improve functional capacity and symptoms.

Phase 3 SCOUT-HCM Supports Expanded Indication

The approval was supported by the Phase 3 SCOUT-HCM trial, a randomized, double-blind, placebo-controlled international study involving 44 adolescents aged 12 to under 18 years with symptomatic NYHA Class II-III oHCM. Patients were randomized to CAMZYOS or placebo and received treatment during a 28-week placebo-controlled period. The trial’s primary endpoint measured the change from baseline in the Valsalva LVOT gradient at Week 28. CAMZYOS produced a statistically significant reduction in the provoked LVOT gradient compared with placebo. According to Bristol Myers Squibb, the mean change was −49.4 mmHg with CAMZYOS compared with −1.8 mmHg with placebo, with a least-squares mean difference of −48.0 mmHg and P<0.0001. FDA noted that this reduction in LVOT obstruction is expected to translate into improved functional capacity and symptoms in pediatric patients, based on the established relationship between LVOT obstruction and clinical outcomes in oHCM.

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Cardiac Myosin Inhibition and Safety Monitoring

CAMZYOS (mavacamten) is a selective, reversible allosteric cardiac myosin inhibitor designed to reduce excessive cardiac contractility associated with oHCM. By reducing cardiac hypercontractility, the therapy can decrease LVOT obstruction and affect cardiac energy use and filling pressures. The expanded indication builds on clinical evidence from adult studies as well as the pediatric SCOUT-HCM program. Safety monitoring remains an important component of treatment because CAMZYOS carries a Boxed Warning for the risk of heart failure due to systolic dysfunction. The prescribing information requires echocardiogram assessments of left ventricular ejection fraction (LVEF) before and during treatment. CAMZYOS is available in the United States only through the restricted CAMZYOS REMS Program, reflecting the need for ongoing cardiac monitoring and management of potential risks. The FDA’s expanded approval represents a significant regulatory development for pediatric obstructive hypertrophic cardiomyopathy, while the SCOUT-HCM results add pediatric clinical evidence to the broader development program for mavacamten. Bristol Myers Squibb said the company is also discussing the pediatric data with regulatory authorities outside the United States. CAMZYOS remains subject to the safety requirements and monitoring provisions specified in its U.S. prescribing information.

Source: Bristol Myers Squibb press release