Cytokinetics' Aficamten Shows Superior Cardiac Benefits Over Standard Treatment in Hypertrophic Cardiomyopathy
Key Insights
Aficamten demonstrated superior improvements in cardiac structure and function compared to metoprolol, the current standard-of-care treatment for obstructive hypertrophic cardiomyopathy (search), in the MAPLE-HCM trial.
New analysis revealed that aficamten significantly improved diastolic function and reduced mitral valve complications that contribute to left ventricular outflow tract obstruction (search).
The annual incidence rate of atrial fibrillation (search) with aficamten was 1.5%, consistent with expected rates in hypertrophic cardiomyopathy (search) patients, supporting the drug's safety profile.
Cytokinetics (search) presented compelling new data at the European Society of Cardiology Congress 2025 demonstrating that aficamten, an investigational cardiac myosin (search) inhibitor, provides superior cardiac benefits compared to metoprolol in patients with obstructive hypertrophic cardiomyopathy (search) (HCM). The findings, simultaneously published in the Journal of the American College of Cardiology, strengthen the evidence base for aficamten as the FDA reviews the drug's New Drug Application with a target action date of December 26, 2025.
MAPLE-HCM Trial Reveals Superior Cardiac Function Improvements
The pre-specified echocardiographic analysis from the MAPLE-HCM trial (Metoprolol vs Aficamten in Patients with LVOT Obstruction on Exercise Capacity in HCM) showed that aficamten was superior to metoprolol at improving measures of diastolic function and reducing the likelihood of mitral valve systolic anterior motion (SAM) and mitral valve leaflet-septal contact, which are primary contributors to left ventricular outflow tract (LVOT) obstruction.
Dr. Sheila Hegde, Assistant Professor at UT Southwestern Medical Center (search) and Affiliate Faculty at Brigham and Women's Hospital, presented the analysis assessing the effect of aficamten relative to metoprolol on cardiac structure and function. The results build upon the primary efficacy analyses that previously demonstrated aficamten's superiority over the current standard-of-care treatment.
"The echocardiographic results from MAPLE-HCM elaborate on the superiority of aficamten compared to the current standard-of-care metoprolol as was previously reported in the primary efficacy analyses," said Fady I. Malik, M.D., Ph.D., Cytokinetics (search)' Executive Vice President of Research & Development.
Atrial Fibrillation Safety Profile Confirmed
A separate analysis examining the incidence and impact of atrial fibrillation (search) across three clinical trials of aficamten in obstructive HCM revealed an annual incidence rate of 1.5%, which is consistent with expected rates in prediction models for patients with HCM. This finding, simultaneously published in Heart Rhythm, was presented as a Late Breaking Clinical Science presentation by Dr. Ahmad Masri, Director of the Hypertrophic Cardiomyopathy (search) Center at Oregon Health & Science University.
The data encompassed results from the REDWOOD-HCM, SEQUOIA-HCM, and FOREST-HCM trials, providing a comprehensive view of aficamten's safety profile across different patient populations and treatment durations.
Regulatory Timeline and Clinical Development
Aficamten is currently under regulatory review by the FDA, with the agency reviewing the New Drug Application under the Prescription Drug User Fee Act (PDUFA) with a target action date of December 26, 2025. The drug candidate has shown positive results from SEQUOIA-HCM, the pivotal Phase 3 clinical trial in patients with obstructive hypertrophic cardiomyopathy (search).
Dr. Malik emphasized that "the additional data presented at the ESC Congress 2025 continue to strengthen the evidence base supporting the overall safety profile of aficamten, including as has been observed with a real-world dosing strategy."
Comprehensive Clinical Trial Program
The presentations at ESC 2025 included five separate data presentations covering various aspects of aficamten's clinical profile. Dr. Sara Saberi from the University of Michigan Health (search) Frankel Cardiovascular Center presented long-term efficacy and safety data from the FOREST-HCM trial, while Dr. Pablo Garcia-Pavia from Hospital Universitario Puerta de Hierro (search) presented the primary results from MAPLE-HCM in a Hot Line session.
Cytokinetics (search) is developing aficamten as part of a broader pipeline of cardiovascular treatments, building on over 25 years of scientific innovations in muscle biology. The company is also evaluating aficamten in additional clinical trials enrolling patients with both obstructive and non-obstructive HCM, expanding the potential therapeutic applications of this cardiac myosin (search) inhibitor.