Camzyos (mavacamten) for Obstructive hypertrophic cardiomyopathy, adolescents

The FDA has already decided. It approved the application.

Details: the outcome and what it means are at the top of this page.

Source: Drugs@FDA, NDA 214998

The FDA approved Bristol Myers Squibb's sNDA for Camzyos in Obstructive hypertrophic cardiomyopathy, adolescents.

What to know: Approved September 30, 2026, on its action date, extending Camzyos to children who weigh at least 30 kg with obstructive hypertrophic cardiomyopathy, and adding a 1 mg capsule for them. It is the first cardiac myosin inhibitor approved for anyone under 18. The approval rests on the Phase 3 SCOUT-HCM trial, in which mavacamten lowered the Valsalva outflow gradient by 48.5 mmHg at week 28 against 0.5 mmHg on placebo. The boxed warning for heart failure and the REMS program with echocardiogram monitoring carry over from the adult label. The FDA had not yet posted the revised label when this entry was written; check the drug page for label details as they are added.

How it works: Selective, reversible, allosteric inhibitor of cardiac myosin that reduces the number of myosin heads able to enter force-producing states, easing the hypercontractility that drives outflow obstruction.

More: the Camzyos drug page explains it in plain language.

Adult approval rested on EXPLORER-HCM (NCT03470545), a 30-week randomized, double-blind, placebo-controlled trial of 251 adults with symptomatic NYHA class II to III obstructive HCM. 37% of patients on mavacamten met the composite primary endpoint of improved exercise capacity and symptoms versus 17% on placebo (p=0.0005). VALOR-HCM (112 patients already referred for septal reduction surgery) then showed that after 16 weeks only 18% on mavacamten still qualified for or chose surgery, versus 77% on placebo.

More: the Camzyos drug page has the full trial history and sources.

In the 251-patient EXPLORER-HCM trial the only reactions occurring in more than 5% of patients and more often than on placebo were dizziness (27% versus 18%) and syncope (6% versus 2%). The safety issue that shapes everything else is the drug's intended effect taken too far: 7 patients on mavacamten (6%) and 2 on placebo had LVEF drop below 50% during the trial, and in all 7 it recovered after the drug was paused.

Most common: dizziness (27% vs 18% on placebo), fainting (syncope, 6% vs 2%).

Boxed warning: Mavacamten reduces left ventricular ejection fraction and can cause heart failure; echocardiograms are required before and during treatment, it should not be started if LVEF is below 55%, and it must be interrupted if LVEF falls below 50% or heart failure symptoms appear.

More: the Camzyos drug page lists the warnings in full.

Trial Friend does not list a price for Camzyos. What you pay depends on your insurance and on help from the drugmaker or a charity fund.

Drugmaker help: MyCAMZYOS Patient Support.

Find help: the patient assistance finder lists programs by insurance type.

This page updates with the outcome the day it is announced.

If approved: getting the drug still takes time. Specialty pharmacy setup, insurance review and patient assistance often take weeks. Our guide covers what families can do on day 1.

If not approved: a complete response letter means the FDA declined the application in its current form. Many are about manufacturing or how data were presented, and companies often resubmit.