FDA approves first drug to improve functional capacity and symptoms in children with rare inherited heart condition

Action

The U.S. Food and Drug Administration (FDA) approved Camzyos (mavacamten) capsules as the first treatment for children with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) to improve functional capacity and symptoms. Camzyos was first approved for adults in 2022 and is now approved for both adults and pediatric patients weighing at least 30 kg (approximately 66 lbs) with symptomatic oHCM.

Disease or Condition

Obstructive hypertrophic cardiomyopathy (oHCM) is a genetically inherited condition that causes a thickened heart muscle. Patients can develop narrowing of the left ventricular outflow tract (LVOT), the outlet from the left side of the heart through which blood leaves to go to the rest of the body. This can cause symptoms such as shortness of breath, fatigue, and an abnormal heart rhythm that can be life-threatening.

Effectiveness

The efficacy of Camzyos was evaluated in SCOUT‑HCM (NCT‑06253221), a phase 3, randomized, double‑blind, placebo‑controlled, multicenter, international study in 44 patients with symptomatic oHCM aged 12-18 years.

Patients were assigned to receive either Camzyos or placebo once daily for 28 weeks. The primary efficacy endpoint was the change from baseline to Week 28 in the pressure generated in the LVOT while bearing down (the Valsalva LVOT gradient), a maneuver that decreases blood flow returning to the heart. Camzyos reduced the Valsalva LVOT gradient significantly compared to placebo, reflecting improved LVOT obstruction. Camzyos has similarly been shown to reduce LVOT obstruction in adults, which was accompanied by improved functional capacity and symptoms. Based on these findings, Camzyos is expected to improve functional capacity and symptoms in pediatric patients with symptomatic oHCM weighing at least 30 kg.

Safety Information

Camzyos has a boxed warning for the risk of heart failure and is only available through a restricted program called the Camzyos Risk Evaluation and Mitigation Strategy (REMS). Side effects that occurred in more than 5% of patients and more often in patients receiving Camzyos compared to patients receiving placebo were dizziness and fainting. See the prescribing information for additional information on risks associated with Camzyos.

Designations

Camzyos received orphan drug designation for this indication.