Cytokinetics has won FDA approval of its cardiac myosin inhibitor, positioning the biotech to challenge Bristol Myers Squibb for the heart disease market.

The approval covers aficamten in adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM), an inherited disease that causes thickening of the heart muscles. People with oHCM have symptoms including shortness of breath. Cytokinetics, which calls the newly approved product Myqorzo, won approval after linking the molecule to significantly improved exercise capacity in patients with the disease.

With analysts expecting Cytokinetics to win approval, the details of the Risk Evaluation and Mitigation Strategy (REMS) were a key focus going into the decision. The FDA delayed the review by three months in May to give itself time to review the biotech’s REMS proposal.