Points
- Mavacamten (2.5 mg, 5 mg, 10 mg, and 15 mg capsules) has received FDA approval to treat individuals with symptomatic New York Heart Association class II-III obstructive hypertrophic cardiomyopathy (HCM) and enhance functional capacity
- The medication “is the first and only FDA-approved allosteric and reversible inhibitor specific for cardiac myosin that targets the fundamental pathophysiology of obstructive HCM,” claims Bristol Myers Squibb (BMS)
Summary
The EXPLORER-HCM long-term extension study, which demonstrated that using mavacamten to cure symptomatic obstructive HCM resulted in ongoing improvements in patient’s life quality and results over an extended period of time, preceded the approval. Mavacamten, specifically, was linked to large and long-lasting benefits in left ventricular outflow tract gradients. The EXPLORER-HCM Phase 3 trial included 251 adult patients with symptomatic (NYHA class II or III), obstructive hypertrophic cardiomyopathy. It was a double-blind, randomized, placebo-controlled, parallel-group trial. At baseline, all individuals showed detectable LVEF (left ventricular ejection fraction) of 55 percent and LVOT peak gradient (resting and/or triggered) of 50 mmHg. Patients receiving monotherapy with ranolazine or disopyramide or combined therapy with beta-blockers and calcium channel blockers were excluded.
Dizziness (27 percent vs. 18 percent) and syncope were two adverse responses in the EXPLORER-HCM study that occurred in more than five percent of patients and were more frequent in the Camzyos (Mavacamten) group than in the placebo group (6 percent vs 2 percent). At the beginning of treatment, the mean (SD) resting LVEF in both treatment groups was 74%. Over the course of the 30-week treatment period, the mean (SD) absolute change in LVEF from baseline was 4 percent in the Camzyos group and 0 percent (7) in the placebo group. After an 8-week break from the trial medication, at Week 38, the mean LVEF for both treatment groups was comparable to baseline. Additionally, while receiving treatment, the LVEF of 7 (6%) Camzyos patients and 2 (2% of the placebo group) patients decreased reversibly to less than 50% (median 48%; range 35-49%). All 7 Camzyos-treated patients experienced LVEF recovery after stopping Camzyos.
Mavacamten comes with a boxed warning regarding the potential risk of heart failure and will only be accessible via the restricted Risk Evaluation and Mitigation Strategy program.
Link to the article: https://www.acc.org/Latest-in-Cardiology/Articles/2022/05/02/12/27/FDA-Update-Mavacamten-Approved-For-Obstructive-HCM
References American College of Cardiology. (2022, May 2). FDA Update: Mavacamten Approved for Obstructive HCM. American College of Cardiology. https://www.acc.org/Latest-in-Cardiology/Articles/2022/05/02/12/27/FDA-Update-Mavacamten-Approved-For-Obstructive-HCM
