MyoKardia’s EXPLORER Trial Big Success

The results of MyoKardia’s Stage 3 EXPLORER study for its experimental drug mavacamten were presented on Saturday at the European Society of Cardiology’s virtual annual meeting and contemporaneously published in The Lancet

The findings from the study showed that mavacamten improved exercise capacity, reduced left ventricular outflow tract gradient (responsible for the obstruction in HCM) and improved New York Heart Association functional class, correlating with a reduction in symptoms and an improvement in quality of life in patients with obstructive hypertrophic cardiomyopathy. 

This was the largest placebo controlled randomized trial ever conducted in HCM. Additionally, mavacamten is the first drug specifically developed for the treatment of hypertrophic cardiomyopathy. All drugs previously used for HCM symptoms were developed to treat other conditions and were used “off label” to treat HCM.

According to Florence, Italy’s Dr. Iacopo Olivotto, who presented the results to ESC’s virtual audience, mavacamten was generally well tolerated and did not appear to have serious side effects.

MyoKardia said the Explorer-HCM data will form the basis of its submission to the FDA which is planned for the first quarter of 2021.  Last month, the company announced that the drug was awarded “Breakthrough Drug” designation by the FDA which it hopes will streamline the approval process.

Also, a new trial comparing mavacamten to septal myectomy and septal alcohol ablation entitled VALOR-HCM for patients with symptomatic, obstructive HCM and who are New York Heart Association Class III – IV who meet the criteria for septal reduction therapy and have been referred for such a procedure has just gotten underway with the first patient enrolled earlier this month.

DISCLOSURES:  HCMBEAT HAS RECEIVED UNRESTRICTED EDUCATIONAL GRANTS FROM MYOKARDIA.  ADDITIONALLY, CYNTHIA BURSTEIN WALDMAN OF HCMBEAT SERVED AS A PATIENT ADVISOR ON THE STEERING COMMITTEE OF MYOKARDIA’S EXPLORER TRIAL and is credited as an author of the study as published in the lancet.  cynthia also serves on myokardia’s patient advisory board.