The U.S. Food and Drug Administration (FDA) has expanded the approval of Bristol Myers Squibb’s Camzyos (mavacamten) to include pediatric patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM).
The approval covers adults and children weighing at least 30 kg (66 pounds) and allows Camzyos to be used to improve functional capacity and symptoms associated with oHCM. The FDA said Camzyos is the first approved treatment for children with symptomatic oHCM.
Obstructive hypertrophic cardiomyopathy is an inherited heart condition in which the heart muscle becomes abnormally thick. This can restrict blood flow from the heart and lead to symptoms such as shortness of breath, fatigue and abnormal heart rhythms.
The expanded approval is supported by results from the Phase 3 SCOUT-HCM trial, which evaluated Camzyos in 44 patients aged 12 to under 18 years with symptomatic oHCM. The study compared 23 patients receiving mavacamten with 21 receiving placebo.
At Week 28, patients treated with Camzyos showed a significant reduction in the Valsalva left ventricular outflow tract (LVOT) gradient compared with those receiving placebo. The least-squares mean difference between the two groups was 48.0 mmHg, with a p-value of less than 0.0001.
Bristol Myers Squibb reported that no patients in the SCOUT-HCM trial experienced a left ventricular ejection fraction below 50%, and no adverse events led to treatment discontinuation. Serious adverse events occurred in two patients in the Camzyos group and two in the placebo group.
Camzyos works by selectively and reversibly inhibiting cardiac myosin, a protein involved in heart muscle contraction. By reducing excessive contraction, the treatment can help reduce obstruction in the heart’s left ventricular outflow tract.
The medicine was first approved in the U.S. in 2022 for adults with symptomatic oHCM. The latest decision expands its use to pediatric patients weighing 30 kg or more.
The approval also comes with important safety requirements. Camzyos carries a boxed warning for the risk of heart failure caused by reduced heart function. Patients require echocardiogram assessments before and during treatment, and the medicine is available through the CAMZYOS Risk Evaluation and Mitigation Strategy (REMS) program.
Bristol Myers Squibb said the pediatric data are also being discussed with regulatory authorities in other countries as the company explores potential approvals for younger patients.
The FDA decision expands treatment options for pediatric patients with symptomatic obstructive hypertrophic cardiomyopathy and adds to the clinical evidence supporting mavacamten in this population.