Effect of Aficamten on Cardiac Structure and Function in Obstructive Hypertrophic Cardiomyopathy: SEQUOIA-HCM CMR Substudy.

BACKGROUND

Obstructive hypertrophic cardiomyopathy (oHCM) is characterized by left ventricular (LV) hypertrophy, LV outflow tract obstruction, and left atrial dilation, which can be associated with progressive heart failure, atrial fibrillation, and stroke. Aficamten is a next-in-class cardiac myosin inhibitor that reduces outflow tract obstruction by modulating cardiac contractility, with the potential to reverse pathological remodeling and, in turn, reduce cardiovascular events.

OBJECTIVES

This study sought to investigate the effect of aficamten on cardiac remodeling compared with placebo using cardiovascular magnetic resonance (CMR) and its association with key clinical endpoints in the SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM) CMR substudy.

METHODS

SEQUOIA-HCM was a phase 3 double-blind, placebo-controlled trial for adults with symptomatic oHCM who were randomized 1:1 to 24 weeks of aficamten (dose range: 5-20 mg) or placebo. Eligible participants were offered enrollment in the CMR substudy with studies performed at baseline and week 24. Image analysis was performed in a blinded fashion by a core laboratory.

RESULTS

Of the 282 randomized patients, 57 (20%) participated in the substudy, and of those, 50 (88%) completed both baseline and week 24 CMR. Baseline characteristics of the CMR cohort were similar to the overall study population. Of these 50 patients, 21 received aficamten and 29 received placebo. Relative to placebo, patients receiving aficamten demonstrated significant reductions (Δ least-squares mean) in LV mass index (-15 g/m

CONCLUSIONS

The CMR substudy of SEQUOIA-HCM demonstrated that treatment with aficamten relative to placebo for 24 weeks resulted in favorable cardiac remodeling. These changes, particularly with regard to LV mass, wall thickness, and left atrial size, could potentially lead to reduced cardiovascular events including heart failure and atrial fibrillation with longer follow-up. (Phase 3 Trial to Evaluate the Efficacy and Safety of Aficamten Compared to Placebo in Adults With Symptomatic oHCM [SEQUOIA-HCM]; NCT05186818).

Informations de copyright

Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.

Déclaration de conflit d'intérêts

Funding Support and Author Disclosures The SEQUOIA-HCM study was funded by Cytokinetics. Dr Masri has received research grants from Pfizer, Ionis, Attralus, and Cytokinetics; and has received fees from Cytokinetics, Bristol Myers Squibb, Eidos/BridgeBio, Pfizer, Ionis, Lexicon, Attralus, Alnylam, Haya, Alexion, Akros, Prothena, BioMarin, AstraZeneca, and Tenaya. Dr Coats has received speaker fees from Alnylam and Roche; and has received advisory fees from Cytokinetics. Dr Hegde has received fees paid to institution for core lab services from Bristol Myers Squibb and Cytokinetics. Dr Lee has received research grants through his employer, the University of Glasgow, from AstraZeneca, Boehringer Ingelheim, and Roche Diagnostics; and is a member of a Trial Steering Committee for Cytokinetics and the Clinical Endpoints Committee for Bayer. Dr Maron has received consulting/advisor fees from Imbria, Edgewise, and Biomarin; and has recevied steering committee fees for SEQUIOA-HCM from Cytokinetics. Dr Michels has received research grant support through her employer, the Erasmus Medical Center, from Bristol Myers Squibb; and has received fees from Cytokinetics, Bristol Myers Squibb, and Alnylam. Dr Olivotto has received research grants from Bristol Myers Squibb, Cytokinetics, Amicus, Genzyme, Shire Takeda, Menarini International, Chiesi, and Boston Scientific; and has received fees from Bristol Myers Squibb, Cytokinetics, Amicus, Genzyme, Shire Takeda, Menarini International, Chiesi, Boston Scientific, Tenaya, Rocket Pharma, and Lexeo. Dr Oreziak has received investigator fees from Cytokinetics and MyoKardia/Bristol Myers Squibb. Dr Jacoby, Dr Heitner, Dr Kupfer, Dr Malik, Ms Meng, and Ms Wohltman are employees of and own stock in Cytokinetics. Dr Solomon has received consulting/advisor fees from Abbott, Action, Akros, Alnylam, Amgen, Arena, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Cardior, Cardurion, Corvia, Cytokinetics, Daiichi-Sankyo, GlaxoSmithKline, Lilly, Merck, MyoKardia, Novartis, Roche, Theracos, Quantum Genomics, Cardurion, Janssen, Cardiac Dimensions, Tenaya, Sanofi Pasteur, Dinaqor, Tremeau, CellProThera, Moderna, American Regent, Sarepta, Lexicon, Anacardio, Akros, and Puretech Health; and has received research grants from Actelion, Alnylam, Amgen, AstraZeneca, Bellerophon, Bayer, Bristol Myers Squibb, Celladon, Cytokinetics, Eidos, Gilead, GlaxoSmithKline, Ionis, Lilly, Mesoblast, MyoKardia, National Institutes of Health/National Heart, Lung, and Blood Institute, Neurotronik, Novartis, Novo Nordisk, Respicardia, Sanofi Pasteur, Theracos, and US2.AI. Dr Kramer has received research grants from Bristol Myers Squibb and Eli Lilly; and has served as a consultant for Eli Lilly. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.