One-year real-world experience with mavacamten and its physiologic effects on obstructive hypertrophic cardiomyopathy

Front Cardiovasc Med. 2024 Aug 30:11:1429230. doi: 10.3389/fcvm.2024.1429230. eCollection 2024.

Abstract

Mavacamten is a first-in-class cardiac myosin ATPase inhibitor, approved by the United States Food and Drug Administration for the treatment of hypertrophic cardiomyopathy with obstructive physiology (oHCM). Here, we present the real-world use of mavacamten in 50 patients with oHCM at a tertiary care referral center. In both our highlighted case and in our aggregate data, we report significant improvement in wall thickness, mitral regurgitation, left ventricular outflow tract obstruction and New York Heart Association symptom class. Moreover, in our center's experience, neither arrhythmia burden, nor contractility have worsened in the vast majority of patients: we note a clinically insignificant mean decrease in left ventricular ejection fraction (LVEF), with only two patients requiring temporary mavacamten discontinuance for LVEF < 50%. Adverse events were rare, unrelated to mavacamten itself, and seen solely in patients with disease too advanced to have been represented in clinical trials. Moreover, our multidisciplinary pathway enabled us to provide a large number of patients with a novel closely-monitored therapeutic within just a few months of commercial availability. These data lead us to conclude that mavacamten, as a first-in-class cardiac myosin inhibitor, is safe and efficacious in real-world settings.

Keywords: MYK-461; cardiac myosin inhibitor; hypertrophic cardiomyopathy; hypertrophic cardiomyopathy with obstruction (oHCM); hypertrophic obstructive cardiomyopathy (HOCM); left ventricular outflow tract obstruction; mavacamten.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. VP has consulting and advisory relationships with BioMarin, Lexeo Therapeutics and Viz.ai and receives funding from BioMarin, the John Taylor Babbitt Foundation, the Sarnoff Cardiovascular Research Foundation, and NHLBI R01HL168059 and K08HL143185. MW reports research grant and in kind support from Bristol Myers Squibb, consulting for Leal Therapeutics, outside the submitted work. EA reports advisory board fees from Apple and Foresite Labs. EA has ownership interest in SVEXA, Nuevocor, DeepCell, and Personalis, outside the submitted work. EA is a board member of AstraZeneca. DK is supported by the Wu-Tsai Human Performance Alliance as a Clinician-Scientist Fellow, the Stanford Center for Digital Health as a Digital Health Scholar, and NIH 1L30HL170306. CW reports consultancy fees from AiRNA Bio and Avidity Biosciences. CW is supported by NIH grants K08HL167699, L30HL159413, F32HL160067 and American Heart Association grant 23CDA1042900.