The U.S. Food and Drug Administration has approved Cytokinetics’ cardiac myosin inhibitor aficamten for use in adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM), marking the company’s first FDA approval since its founding in 1997. The therapy will be marketed under the commercial name Myqorzo.
The approval places Cytokinetics into a market that already includes Bristol Myers Squibb’s Camzyos, a drug whose development involved Cytokinetics through a prior partnership. In 2012, Cytokinetics partnered with MyoKardia, contributing to the development of Camzyos.
Bristol Myers Squibb later acquired MyoKardia for $13.1 billion, and Camzyos received FDA approval in 2022. Both Myqorzo and Camzyos are cardiac myosin inhibitors that bind to the myosin protein and block interactions responsible for hypertrophic cardiomyopathy, reducing excessive cardiac contraction and obstruction in the left ventricular outflow tract.
In a statement announcing the approval, Cytokinetics Chief Executive Officer Robert Blum said, “Our first FDA approval stands as a testament to the strength of our science and the bold, trailblazing research that has defined Cytokinetics’ leadership in muscle biology.”
Because Myqorzo relaxes the heart muscle, it carries a boxed warning related to the risk of heart failure and is subject to a Risk Evaluation and Mitigation Strategy. The FDA had delayed its review earlier this year to allow additional time to evaluate Cytokinetics’ proposed REMS. While Camzyos is also subject to boxed warnings and REMS requirements, analysts have highlighted differences in how the two programs are structured.
Analysts from Mizuho Securities and Evercore ISI have said Myqorzo is differentiated based on its kinetics, dosing flexibility, and overall drug profile. Cytokinetics has stated that the approved REMS allows physicians to titrate dosing as early as two weeks and to conduct echocardiogram assessments two to eight weeks after dose initiation or adjustment.
Dosing can be adjusted following each echocardiogram without delay, and patients receiving 10 mg or 15 mg doses may reach their target dose within four to six weeks, according to company executives.
The FDA approval was supported by data from a phase 3 study showing that Myqorzo improved exercise capacity, measured by increases in peak oxygen uptake compared with placebo. Data from the MAPLE-HCM study, presented at the 2025 European Society of Cardiology Congress, showed that after 24 weeks of treatment, patients receiving aficamten experienced a 1.1 mL/kg/min increase in peak oxygen uptake. Patients treated with the standard-of-care beta blocker metoprolol experienced a 1.2 mL/kg/min decrease over the same period.
Hypertrophic cardiomyopathy is the most common monogenic inherited cardiovascular disorder. More than 300,000 patients have been diagnosed in the United States, while an estimated 400,000 to 800,000 additional patients remain undiagnosed, according to Cytokinetics. About half of the patients have obstructive disease, while the remainder have non-obstructive hypertrophic cardiomyopathy. Cytokinetics is currently conducting a phase 3 study in patients with the non-obstructive form of the disease.
Cytokinetics plans to launch Myqorzo in the second half of January and has not yet disclosed pricing. Bristol Myers Squibb has reported Camzyos sales of $602 million in 2024 and $715 million through the first nine months of this year, with an annual wholesale acquisition cost of approximately $104,000. Cytokinetics said it will provide additional details during a Monday afternoon webcast scheduled to begin at 4:30 p.m. ET.
The FDA’s review and approval of Myqorzo reflects ongoing efforts to broaden treatment options for patients with serious heart conditions. Regulatory decisions like this involve a detailed review of safety and efficacy data, as well as strategies such as REMS to ensure appropriate use and monitoring in clinical practice.
The FDA approval of Myqorzo positions Cytokinetics to contribute meaningfully to the management of oHCM, particularly as clinicians seek therapies tailored to patients’ needs and risk profiles.
Looking ahead, Cytokinetics plans to launch Myqorzo in the United States in the second half of January 2026, with additional details on pricing and access expected to be disclosed soon. Patients, clinicians, and industry observers alike will be watching closely as Myqorzo enters the market and joins other targeted therapies for hypertrophic cardiomyopathy. Continued post-approval research and real-world experience will help further refine its place in clinical practice.
