EC approval of cardiac myosin inhibitor for treatment of symptomatic obstructive HCM
The European Commission (EC) has approved mavacamten for the treatment of adult patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM).
News - June 27, 2023The cardiac myosin inhibitor mavacamten has been approved in all European Union (EU) member states for use in adult patients with symptomatic (NYHA class II-III) obstructive hypertrophic cardiomyopathy (HCM). This approval is based on the positive results from two phase 3 trials, EXPLORER-HCM and VALOR-HCM. Mavacamten is a allosteric and reversible inhibitor selective for cardiac myosin.
The EXPLORER-HCM and the VALOR-HCM trials were double-blind, randomized, placebo-controlled phase 3 trials enrolling patients with symptomatic, obstructive HCM.
In the EXPLORER-HCM trial, the primary endpoint -a composite functional endpoint of the proportion of patients who achieved either improvement of mixed venous oxygen tension (pVO₂) by ≥1.5 mL/kg/min plus improvement in NYHA class by at least 1 or improvement of pVO₂ by ≥3.0 mL/kg/min plus no worsening in HYHA class at week 30 – was achieved in 37% of patients taking mavacamten vs. 17% in patients on placebo (difference of 19.4%, 95%CI:8.67-30.13, P=0.0005).
The VALOR-HCM trial showed that treatment with mavacamten resulted in reduction of the primary composite endpoint -the patient’s decision to proceed with SRT prior to or at week 16 or patients who remain SRT eligible at week 16. 17.9% of patients treated with mavacamten vs. 76.8% of patients in the placebo group decided to proceed with SRT prior to or at week 16 or were SRT-eligible at week 16 (difference of 58.9%, 95%CI:44.0%-73.9%, P<0.0001).
Pooled safety data showed that the most commonly reported adverse reactions were dizziness, dyspnea, systolic dysfunction and syncope.