Cytokinetics presents data related to aficamten at HFSA Meeting 2025

Cytokinetics (CYTK) announced that additional data related to aficamten were presented in a Late Breaking Clinical Research session at the Heart Failure Society of America Annual Scientific Meeting 2025 in Minneapolis, MN. The first presentation was a pre-specified analysis of the effect of aficamten compared to metoprolol on exercise performance in obstructive HCM in MAPLE-HCM, and the second was an analysis from FOREST-HCM on the efficacy and tolerability of long-term treatment of aficamten in patients with non-obstructive hypertrophic cardiomyopathy, simultaneously published in the Journal of Cardiac Failure. Gregory Lewis, M.D., Jeffrey and Mary Ellen Jay Chair and Section Head, Heart Failure Medical Director, Cardiopulmonary Exercise Testing Laboratory, Professor of Medicine, Harvard Medical School presented pre-specified supplemental analyses of the impact of treatment with aficamten relative to metoprolol on CPET measures of exercise performance from onset through post-exercise recovery in MAPLE-HCM. The primary result of MAPLE-HCM demonstrated the superiority of aficamten to metoprolol on peak oxygen uptake. In these new analyses, aficamten compared to metoprolol was also shown to nominally significantly improve measures of submaximal exercise performance, including anaerobic threshold, aerobic efficiency, ventilatory efficiency, and other key measures of maximal exercise performance, including peak workload, peak heart rate, exercise duration and heart rate reserve. Additionally, the speed of VO2 recovery, a sensitive measure of cardiometabolic resilience, increased with aficamten and slowed with metoprolol. A responder analysis showed that any improvement in pVO2 was observed more commonly with aficamten compared to metoprolol, while any worsening was more frequent in the metoprolol group. Ahmad Masri, M.D., MS, Director of the Hypertrophic Cardiomyopathy Center at Oregon Health & Science University, presented new data related to the safety and long-term use of aficamten in patients with nHCM in FOREST-HCM. These analyses included 34 patients with nHCM who enrolled in FOREST-HCM, the open-label extension study, after completion of Cohort 4 of the Phase 2 clinical trial REDWOOD-HCM. Patients were followed for at least 96 weeks of treatment. At the end of titration, 82.4% of patients were on the highest available doses of 15 mg and 20 mg. Through 96 weeks of treatment, there were no early treatment discontinuations and aficamten demonstrated sustained reductions in symptom burden. At Week 96, 27 of the 34 patients improved by at least one NYHA Functional Class, including 20 who became asymptomatic. Patients also experienced a mean increase in the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score of 11.2 points. Aficamten also improved cardiac biomarkers, with both NT-proBNP and high-sensitivity cardiac troponin I rapidly declining by Week 12 and remaining low through Week 96. There was a modest reduction in left ventricular ejection fraction from hyperdynamic at baseline to within normal range at Week 12. Over the treatment period, four patients had LVEF less than50% which were reversible after down titration or a short treatment interruption. Only one instance of LVEF less than50% was corroborated by the core lab. The efficacy and safety of aficamten in non-obstructive HCM is being investigated in an ongoing Phase 3 clinical trial.