New data related to Myqorzo (aficamten) announced at ESC Heart Failure 2026 – Cytokinetics
Cytokinetics, Incorporated announced the presentation of new data reinforcing the clinical profile of Myqorzo (aficamten) at the European Society of Cardiology (ESC) Heart Failure 2026 Congress. The presentations include new analyses from SEQUOIA-HCM, the pivotal Phase III clinical trial of aficamten in patients with oHCM; MAPLE-HCM, the Phase III clinical trial of aficamten compared to metoprolol in patients with symptomatic obstructive HCM (oHCM); and FOREST-HCM, the open-label extension trial of aficamten.
Collectively, the new evidence expands understanding of the effectiveness of cardiac myosin inhibition with aficamten compared directly to metoprolol, a beta blocker, as well as specific safety and durability characteristics of Myqorzo across patient demographics, clinical, and economic subgroups.
“The breadth of research being presented at ESC Heart Failure 2026 reflects our commitment to deepening the scientific understanding of oHCM and heart failure,” said Stephen Heitner, M.D., Senior Vice President, Clinical Research and Development, Cytokinetics. “These new insights underscore the strength and consistency of the clinical profile of Myqorzo, adding to the growing body of real-world evidence informing physician treatment decisions.”
New Analyses Show Myqorzo Outperforms Metoprolol Across Sex and Doses
A dose-dependent analysis from MAPLE-HCM compared aficamten to the beta-blocker metoprolol in patients with symptomatic oHCM. Key findings showed significant improvements in exercise capacity, outflow gradients, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) across all treatment doses. Conversely, metoprolol failed to show improvement in these outcomes regardless of the dose administered (Figure 1).
A secondary analysis of sex differences in MAPLE-HCM showed consistent benefits of Myqorzo in women. Despite women entering the trial (42%) with more severe baseline characteristics, Myqorzo delivered nearly identical improvements in peak oxygen consumption (pVO2) for both sexes (+2.2 mL/kg/min). Both groups also saw significant gains in Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) and reductions in cardiac biomarkers and NT-proBNP.
Long-term Data Reinforce Safety and Efficacy Profile of Myqorzo
A prospective analysis of 122 patients who had interpretable ambulatory electrocardiogram (ECG) data at screening in the FOREST-HCM showed that long-term treatment with Myqorzo—up to 96 weeks—did not increase the incidence of arrhythmias in patients, including those who underwent withdrawal of beta-blocker therapy.
Among 122 patients, the incidence of non-sustained ventricular tachycardia (NSVT) on ambulatory ECG remained stable through 96 weeks compared with baseline, with no increase in atrial fibrillation (AF) episodes and no newly identified subclinical AF. There was also no increase in arrhythmia frequency among a subgroup of 16 patients who discontinued beta-blocker therapy during aficamten treatment. These results represent the first prospective analysis of ambulatory ECG monitoring in patients treated with a cardiac myosin inhibitor and are consistent with the low incidence of clinically detected arrhythmias previously reported for patients with oHCM treated with aficamten.
Additionally, an open-label extension study of aficamten in Chinese patients with symptomatic oHCM showed that aficamten was well tolerated using the same dosing strategy of individualized titration as was used globally. Through 48 weeks of treatment with aficamten, patients experienced no serious or severe treatment-emergent adverse events, no occurrences of LVEF <50% and no treatment discontinuations. Significant and durable improvements from baseline were observed in resting and Valsalva left ventricular outflow tract (LVOT) gradients (−40.3 mmHg and −45.6 mmHg, respectively; both p<0.001), New York Heart Association (NYHA) Functional Class ≥1 (15% p = 0.024), KCCQ-CSS (+8.3 points; p<0.001) and NT-proBNP (−59.2%; p<0.001).
New Evidence Indicates Positive Effects of Myqorzo on Left Atrium Remodeling and Atrial Mechanics
Expanded insights from SEQUOIA-HCM provide the first-ever analysis of the effect of aficamten on left atrial (LA) mechanics in oHCM. This analysis was performed to determine whether Myqorzo improved LA function in addition to previously demonstrated improvement in exercise capacity by relieving left ventricular outflow tract (LVOT). The new data showed that across the key clinical subgroups, Myqorzo, compared with placebo, significantly improved LA mechanics, which correlated with improvement in functional capacity in oHCM.
Among 269 patients, LA function was abnormal at baseline, with 94% of participants having reduced LA reservoir and conduit strain. Compared with placebo, aficamten significantly improved LA reservoir strain (treatment effect +2.9%; p=0.004) and absolute LA conduit strain (+2.2%; p=0.001) and reduced LA volume index (−3.5 mL/m2; p<0.001). These findings extend prior evidence that aficamten favorably remodels left atrial structure and suggest a beneficial effect on atrial mechanics.
Real-World Evidence Highlights Unmet Need and the Significant Burden of HCM
Multiple presentations provide new multinational real-world evidence and health economics and outcomes data underscoring the burden of HCM across disease subtypes and need for effective therapies that address the underlying disease mechanisms of HCM in adult and pediatric patients across the spectrum of symptomatic disease.
Work & Activity Impairment: A survey of 273 patients in Italy, Spain and the United States revealed that patients with oHCM reported, on average, 26.6% activity impairment due to the disease. Full-time and part-time employed patients with HCM reported that 15.35% of their time at work was impaired due to HCM in the past 7 days and, on average, they missed 1.63% of work time. Activity impairment was significantly higher among those with oHCM compared with non-obstructive HCM (nHCM) (30.2% vs 19.2%; p=0.0003).
A separate analysis of 701 U.S. patients with HCM from the Adelphi Real World Disease Specific Programme, showed that patients classified as NYHA II–IV Functional Class reported higher symptom burden, greater cardiovascular comorbidity, greater healthcare resource utilization (including emergency room (ER) visits, day visits and caregiver hours) and lower quality of life (EQ-5D-5L and EQ-VAS) compared with patients in NYHA Class I. Notably, patients in NYHA Class I continued to experience clinical symptoms and require medical care, underscoring the need for therapies that address the underlying mechanisms of HCM across the spectrum of symptomatic disease.
Limitations of Current Therapy: An analysis of 723 patients with nHCM showed that despite 70% being on guideline-directed medical therapy such as beta-blockers, they continued to experience substantial clinical and economic burdens.
Clinical Burden of Pediatric Hypertrophic Cardiomyopathy: A retrospective cohort study characterized the real-world epidemiology of pediatric HCM in the United States using administrative claims data from 6,093 children and adolescents diagnosed between 2016 and 2024. Approximately one in four children with HCM had obstructive disease (23.6%), and roughly one in four were symptomatic at presentation, underscoring the needs of the pediatric oHCM population that may be targeted by emerging disease-modifying therapies, including aficamten, which is currently under investigation in CEDAR-HCM, a Phase III trial in pediatric patients with oHCM.
A separate study analyzed the phenotypic distribution and clinical burden of pediatric HCM based on a longitudinal U.S. claims database, showing that pediatric patients with HCM experience substantial clinical burden. Obstructive HCM was associated with a higher cumulative risk of cardiovascular events compared with nHCM. These findings demonstrate clinically relevant heterogeneity in pediatric HCM and may inform risk mitigation strategies.
