On December 19, 2025, the FDA cleared MYQORZO, the brand name for aficamten, a cardiac myosin inhibitor for adults with symptomatic obstructive hypertrophic cardiomyopathy. For Cytokinetics, a South San Francisco biotech founded in 1997, the approval ended a 27-year run as a clinical-stage company without a commercial product, a span that included a failed ALS program and an FDA rejection of its heart failure drug in 2023.
MYQORZO became available by prescription on January 27, 2026. Institutional investors including BlackRock, Fidelity, Vanguard, T. Rowe Price, Deep Track Capital, and Armistice Capital held positions in Cytokinetics as the commercial launch began.
The Disease and How MYQORZO Addresses It
Obstructive hypertrophic cardiomyopathy is a condition in which an abnormally thickened cardiac muscle impairs blood flow out of the heart, limiting exercise capacity and causing shortness of breath, chest pain, and in some cases fainting. Cytokinetics estimates at least 100,000 patients in the United States are eligible for treatment.
MYQORZO works by reducing cardiac myosin activity, lowering the overall force of ventricular contraction and decreasing the left ventricular outflow tract gradient that drives symptoms in obstructive HCM. The FDA approval rested on data from the Phase 3 SEQUOIA-HCM trial, in which aficamten improved peak oxygen uptake by 1.8 milliliters per kilogram per minute compared with placebo, the primary endpoint used to assess functional severity in HCM.
MYQORZO carries a Risk Evaluation and Mitigation Strategy requiring echocardiographic assessment of left ventricular ejection fraction before treatment begins and at intervals during dose titration. The drug’s label includes a boxed warning for heart failure risk and is not recommended for patients with LVEF below 55 percent.
A Second Drug in an Underserved Market
MYQORZO enters a category Bristol Myers Squibb’s Camzyos has occupied alone since 2022. Camzyos generated more than $1 billion in combined U.S. and European sales in 2025. Both drugs target cardiac myosin. The practical competitive difference lies in their REMS protocols and prescribing conditions.
Camzyos requires drug-drug interaction monitoring, regular echocardiograms, and dose interruption in certain scenarios, administrative requirements that have created friction for prescribers and pharmacies managing the category. MYQORZO’s label allows dose adjustment rather than full interruption in most situations and does not require drug-interaction monitoring. RBC Capital Markets analyst Leonid Timashev wrote after the FDA approval that those differences should “materially lower barriers to prescribing” for MYQORZO relative to Camzyos.
Cytokinetics set a commercial target of more than 50 percent new-to-brand prescription share among patients entering the cardiac myosin inhibitor class in 2026. More than 80 percent of the eligible obstructive HCM population in the United States remains untreated with either drug.
Launch Operations
More than 125 U.S. field sales colleagues were deployed at launch, concentrated initially on roughly 750 high-volume cardiologists who account for approximately 80 percent of current cardiac myosin inhibitor prescriptions. The broader outreach extends to approximately 11,000 cardiologists nationwide. Within weeks, more than 700 cardiologists had completed REMS enrollment and training.
A patient bridge program provides up to 12 months of free drug for commercially insured patients without active coverage and up to two months for Medicare patients awaiting formulary decisions. Commercial insurance access comparable to Camzyos is projected for the fourth quarter of 2026. Cytokinetics entered the year with approximately $1.2 billion in cash, providing runway through the payer access-building period.
European Expansion and ACACIA-HCM
The European Commission granted marketing authorization for MYQORZO in early 2026 following a positive recommendation from the EMA’s Committee for Medicinal Products for Human Use. Germany is the initial European market, with a launch targeted for the second quarter of 2026 under the AMNOG framework. Broader Western European markets are planned for later in 2026 and into 2027.
The most closely watched clinical event on Cytokinetics’ 2026 calendar is the Phase 3 ACACIA-HCM trial, testing aficamten in symptomatic non-obstructive HCM. Non-obstructive disease has no approved treatment and accounts for roughly half the diagnosed and symptomatic HCM population in the United States. Camzyos failed in Phase 3 for this indication. Data from ACACIA-HCM is expected in the second quarter of 2026, and a positive result would leave Cytokinetics as the only company with approved therapies for both forms of the disease.
