Bristol Myers Squibb’s Camzyos (mavacamten) has won expanded US approval for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM) in adults and pediatric patients weighing at least 30 kilograms (66 pounds), opening the door to the drug’s use in a younger patient population.

 

The US Food and Drug Administration approval makes Camzyos the only FDA-approved therapy for oHCM in a pediatric population, according to Bristol Myers Squibb. The company said the expanded indication gives Camzyos the broadest indication of any cardiac myosin inhibitor.

 

The approval is based on results from the Phase 3 SCOUT-HCM trial, which enrolled 44 adolescents aged 12 to under 18 with symptomatic oHCM.

 

“Today’s approval of CAMZYOS for pediatric patients with symptomatic obstructive hypertrophic cardiomyopathy marks an important milestone for young patients and families who are facing a serious cardiovascular disease with significant unmet medical need,” said Al Reba, senior vice president, Immunology & Cardiovascular Commercialization, Bristol Myers Squibb. 

 

“For young patients living with this disease, the burden on daily life can be substantial during a critical stage of development, and we are proud to help bring an innovative new treatment option to this community. This approval also strengthens the growing body of clinical evidence supporting CAMZYOS, which is the most extensively studied cardiac myosin inhibitor with up to five years of follow up in adults, and its role in the treatment of oHCM.”

 

In SCOUT-HCM, patients were randomly assigned to receive either Camzyos or placebo for 28 weeks. The trial’s primary endpoint was the change in the provoked Valsalva left ventricular outflow tract (LVOT) gradient.

 

Camzyos produced a mean reduction of 49.4 mmHg, compared with a 1.8 mmHg reduction with placebo. The least-squares mean difference was 48.0 mmHg, with a 95% confidence interval of -67.7 to -28.3 and a P value below 0.0001.

 

The study also reported reductions in resting and postexercise LVOT gradients, as well as a reduction in maximum left ventricular wall thickness.

 

In the trial, no patients receiving Camzyos had a left ventricular ejection fraction below 50%, and no adverse events led to treatment discontinuation. Serious adverse events were reported in two patients in each group.

 

“The FDA approval of CAMZYOS for pediatric patients with symptomatic obstructive hypertrophic cardiomyopathy represents a landmark moment for pediatric cardiology. For the first time, children with this serious condition have a therapy that is FDA-approved to reduce left ventricular outflow tract obstruction,” said Joseph Rossano, Principal Investigator of SCOUT-HCM and Chief of the Division of Cardiology at Children’s Hospital of Philadelphia. 

 

“This historic milestone was made possible by the outstanding efforts of the international SCOUT-HCM investigators and participating families whose commitment has transformed clinical research into a therapy with potential to meaningfully improve the lives of pediatric patients with symptomatic obstructive hypertrophic cardiomyopathy.”

 

The trial’s longer-term program includes an additional 28-week active-treatment period followed by an open-label extension of up to 144 weeks.

 

Hypertrophic cardiomyopathy is an inherited or otherwise unexplained disorder in which the heart muscle becomes abnormally thickened. In children with obstructive HCM, the disease can be associated with ventricular arrhythmias, heart failure and atrial fibrillation.

 

Treatment has historically included beta blockers, calcium channel blockers and disopyramide, with invasive septal reduction procedures used in some patients.

 

“I cannot help but think back to my 12-year-old self receiving my diagnosis and being told there were no treatment options approved specifically for my disease,” said Lisa Salberg, CEO and founder of the Hypertrophic Cardiomyopathy Association. 

 

“This is truly a milestone moment for patients and families. Having a targeted therapy for cardiac myosin is a significant breakthrough, and it's a welcome change to bring this approval to a younger population. Thank you to all of the researchers, scientists, and the entire HCM ecosystem that has helped bring this new therapy to more patients.”