Cytokinetics Reports Positive Phase 3 Results for Aficamten in Heart Disease

Cytokinetics has reported encouraging top-line outcomes from its phase 3 MAPLE-HCM trial, which evaluated aficamten, an investigational oral cardiac myosin inhibitor, in treating hypertrophic cardiomyopathy (HCM). This study assessed aficamten against the commonly used beta blocker, metoprolol, involving over 170 participants with symptomatic obstructive Hypertrophic Cardiomyopathy.

HCM is a prevalent genetic heart disease affecting roughly one in 500 individuals in both the UK and the US. The condition often goes undiagnosed because some patients do not exhibit symptoms. For those who do, symptoms like chest pain and shortness of breath usually surface during physical exertion. Among those diagnosed with HCM, approximately two-thirds suffer from the obstructive form. This subtype is characterized by the thickening of heart muscle that limits or blocks blood flow from the heart. The non-obstructive version, where the heart muscle thickens but does not obstruct blood flow, is less frequently observed.

Aficamten aims to mitigate the excessive contractility linked with HCM by inhibiting myosin, a motor protein essential for muscle contraction. The MAPLE-HCM trial successfully met its primary endpoint, demonstrating that aficamten significantly enhances peak oxygen uptake compared to metoprolol from the start of the study to the 24-week mark. This was evaluated using cardiopulmonary exercise testing. Additionally, aficamten exhibited a favorable safety and tolerability profile relative to metoprolol during the study.

Dr. Fady Malik, Cytokinetics’ executive vice president of research and development, emphasized the significance of these findings, stating they are the first to indicate that aficamten could be effectively used as a standalone treatment to provide meaningful clinical improvements for those living with obstructive HCM. He highlighted that the MAPLE-HCM results offer vital insights into the benefits of aficamten compared to the current treatment standards.

Beyond the MAPLE-HCM trial, aficamten is also under investigation for its efficacy in treating non-obstructive HCM. The drug is currently undergoing regulatory scrutiny by the US Food and Drug Administration (FDA), with a decision anticipated by December 26. Furthermore, the European Medicines Agency is also evaluating aficamten.

This progress in the development of aficamten marks a potential advancement in the management of HCM, providing hope for a more effective treatment option that can improve the quality of life for those affected by this genetic heart disease. The promising outcomes from the MAPLE-HCM trial not only underscore the potential of aficamten as an alternative to traditional beta blockers like metoprolol but also reinforce the importance of continued research and innovation in cardiac treatment therapies. As the regulatory review processes unfold, the medical community remains attentive to the potential approval of aficamten and its subsequent impact on HCM treatment paradigms.