Cytokinetics Inc.’s (CYTK) New Drug Application for Aficamten for the treatment of patients with obstructive hypertrophic cardiomyopathy is under FDA review, with a decision anticipated on December 26, 2025.Hypertrophic cardiomyopathy (HCM) is a disease in which the heart muscle (myocardium) becomes abnormally thick, which causes the left ventricle to become smaller and stiffer, ultimately impairing the heart’s ability to pump blood effectively. This results in reduced exercise capacity and symptoms including chest pain, dizziness, shortness of breath, or fainting during physical activity. In the U.S., approximately 280,000 people have been diagnosed with HCM, with an estimated 400,000-800,000 additional patients who remain undiagnosed. Two-thirds of patients with HCM have obstructive HCM (oHCM), where the thickening of the cardiac muscle leads to left ventricular outflow tract (LVOT) obstruction, while one-third have non-obstructive HCM (nHCM), where blood flow isn’t impacted, but the heart muscle is still thickened.Aficamten is an investigational, oral, small molecule that inhibits cardiac myosin, a protein best known as the molecular motor that powers heart contraction.In clinical trials, Aficamten had a positive impact on exercise capacity, clinical outcomes, symptom burden and cardiac biomarkers in patients with HCM, with a consistent effect across all prespecified subgroups and a favourable safety and tolerability profile.Under an agreement signed in 2024, Royalty Pharma plc (RPRX) is providing capital to support the commercialization of Aficamten.The potential peak sales for Aficamten are estimated to be in the range of $4 billion, according to analysts.CYTK closed Wednesday’s (November 26, 2025) trading at $68.15, up 0.89%.