Mavacamten shows potential for treating hypertrophic cardiomyopathy in EXPLORER-HCM trial

Mavacamten has demonstrated value as a treatment option for patients with obstructive hypertrophic cardiomyopathy (HCM), according to results from the EXPLORER-HCM phase III clinical trial.

EXPLORER-HCM included 251 patients with symptomatic obstructive HCM. Participants received either a daily dose of mavacamten or a placebo for 30 weeks. MyoKardia, the drug’s manufacturer, reported that mavacamten use was associated with improved symptoms, a better quality of life and a reduction in obstruction of the left ventricle. Ninety-eight percent of participants completed the trial, and MyoKardia said the 2% that did drop out were not related to reduced ejection fraction or heart failure symptoms. Rates of adverse events, serious adverse events and cardiac adverse events were similar for patients treated with mavacamten and the placebo.

“The extraordinary data from the EXPLORER pivotal trial confirm mavacamten’s ability to relieve dynamic outflow obstruction, control symptoms and improve quality of life in patients with hypertrophic cardiomyopathy,” lead clinical investigator Iacopo Olivotto, MD, Careggi University Hospital, said in a statement from MyoKardia. “HCM is the most common inherited cardiovascular disease, and patients face an uncertain journey that all too frequently includes debilitating symptoms, as well as serious complications, such as heart failure, stroke and cardiac arrest. Mavacamten is the first drug developed to target the specific molecular defect of the disease. EXPLORER represents a major achievement toward a precision-medicine approach in cardiomyopathies and should provide great hope to a community painfully aware of the lack of disease-specific treatment options.”

“The resoundingly positive data from EXPLORER bring us a significant step closer to improving the lives of people with serious cardiovascular conditions, starting with HCM, a debilitating disease estimated to affect one in every 500 people,” Tassos Gianakakos, CEO of MyoKardia, said in the same statement. “The activity and tolerability profile observed for mavacamten in this pivotal study underscores the profound impact and potential for therapeutics that target the underlying biology of disease.” 

Looking forward, MyoKardia aims to share its full EXPLORER-HCM results at a professional meeting sometime in 2020. In early 2021, the company will begin the process of submitting a New Drug Application to the FDA.