On Dec. 19, 2025, Cytokinetics announced that the U.S. Food and Drug Administration (FDA) has approved MYQORZO™ (aficamten), 5 mg, 10 mg, 15 mg, 20 mg tablets for the treatment of adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) to improve functional capacity and symptoms. MYQORZO is an allosteric and reversible inhibitor of cardiac myosin motor activity. In patients with oHCM, myosin inhibition with MYQORZO reduces cardiac contractility and left ventricular outflow tract (LVOT) obstruction.

The full U.S. Prescribing Information for MYQORZO includes a Boxed WARNING for the risk of heart failure. MYQORZO reduces left ventricular ejection fraction (LVEF) and can cause heart failure due to systolic dysfunction. Echocardiogram assessments are required prior to and during treatment with MYQORZO to monitor for systolic dysfunction. Initiation of MYQORZO in patients LVEF <55% is not recommended. Decrease the dose of MYQORZO if LVEF <50% and ≥40%. Interrupt the dose of MYQORZO if LVEF <40% or if the patient experiences heart failure symptoms or worsening clinical status due to systolic dysfunction.

Because of the risk of heart failure due to systolic dysfunction, MYQORZO is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the MYQORZO REMS Program.

MYQORZO is expected to be available in the U.S. in the second half of January 2026. Cytokinetics will support patients with MYQORZO & You™, a personalized program for patients prescribed MYQORZO in the U.S. to help navigate the treatment journey, provide disease and product education, and offer support with insurance benefits investigations or financial assistance for those eligible.

The approval is based on the positive results from the pivotal Phase 3 clinical trial, SEQUOIA-HCM, published in the New England Journal of Medicine, which demonstrated robust efficacy, safety, and clinically meaningful benefits across symptoms, exercise capacity, hemodynamics, and biomarker endpoints. The results from SEQUOIA-HCM showed that treatment with MYQORZO for 24 weeks significantly improved exercise capacity compared to placebo, increasing peak oxygen uptake (pVO₂) measured by cardiopulmonary exercise testing (CPET) by 1.8 mL/kg/min compared to baseline in patients treated with MYQORZO versus 0.0 mL/kg/min in patients treated with placebo (least square mean (LSM) difference [95% CI] of 1.74 mL/kg/min [1.04 – 2.44]; p=0.000002). The treatment effect of MYQORZO was consistent across all prespecified subgroups, including age, sex, patient baseline characteristics, and in patients receiving or not receiving background beta-blocker therapy.

MYQORZO was well-tolerated, with no instances of worsening heart failure or treatment interruptions due to low LVEF. Treatment emergent serious adverse events occurred in 5.6% of patients on MYQORZO and 9.3% of patients on placebo. Core laboratory echocardiographic LVEF was observed to be <50% in 5 patients (3.5%) on MYQORZO compared to 1 patient (0.7%) on placebo. Hypertension (8% vs 2%) was the only adverse reaction occurring in >5% of patients and more commonly on MYQORZO than on placebo. MYQORZO-associated increases in blood pressure are consistent with relief of LVOT obstruction and improved cardiac output.