The U.S. Food and Drug Administration has approved mavacamten (Camzyos, Bristol Myers Squibb) to improve functional capacity and symptoms in adults with symptomatic New York Heart Association (NYHA) class II-III obstructive hypertrophic cardiomyopathy (oHCM).
Mavacamten is the first FDA-approved allosteric and reversible inhibitor selective for cardiac myosin that targets the underlying pathophysiology of the genetic disorder. It’s available in 2.5-mg, 5-mg, 10-mg, and 15-mg capsules.
“The approval of Camzyos represents a significant milestone for appropriate symptomatic obstructive HCM patients and their families, who have long awaited a new treatment option for this chronic and progressive disease,” Anjali T. Owens, MD, medical director of the Center for Inherited Cardiac Disease and assistant professor of medicine, University of Pennsylvania, Philadelphia, said in a news release.
The approval of mavacamten was based on data from the pivotal EXPLORER-HCM and EXPLORER-LTE (long-term extension) trial of adults with symptomatic NYHA class II-III oHCM.
In EXPLORER-HCM, treatment with mavacamten over 30 weeks led to significant improvement in exercise capacity, left ventricular outflow tract (LVOT) obstruction, NYHA functional class, and health status, as reported by this news organization.
The safety and efficacy findings seen at the end of the blinded, randomized, initial 30-week phase of EXPLORER-LTE were maintained in patients who continued treatment for a median of about 62 weeks.
Mavacamten represents “an almost revolutionary change” for the treatment of oHCM, Maya E. Guglin, MD, professor of clinical medicine and an advanced heart failure physician at Indiana University, Indianapolis, said during a press briefing earlier this month at the American College of Cardiology 2022 Scientific Session earlier this month.
“Until now, there was no good medical treatment for symptomatic oHCM. This will change the landscape, and without question it will change guidelines for treating oHCM,” Dr. Guglin said.
The product information for mavacamten includes a boxed warning citing a risk for heart failure.
Echocardiogram assessments of left ventricular ejection fraction (LVEF) are required before and during treatment.
Starting mavacamten in patients with LVEF below 55% is not recommended and the drug should be interrupted if LVEF falls below 50% at any visit or if the patient experiences heart failure symptoms or worsening clinical status.
Concomitant use of mavacamten with certain cytochrome P450 inhibitors or discontinuation of certain cytochrome P450 inducers can increase the risk for heart failure attributable to systolic dysfunction. Therefore, its use is contraindicated in patients using moderate to strong CYP2C19 inhibitors or strong CYP3A4 inhibitors, and moderate to strong CYP2C19 inducers or moderate to strong CYP3A4 inducers.
Because of the risk for heart failure attributable to systolic dysfunction, mavacamten is only available through the Camzyos Risk Evaluation and Mitigation Strategy (REMS) Program.
Full prescribing information is available online.
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