Pharmacists play a large role in mavacamten care, screening for interacting drugs that can raise exposure and may require dose adjustment or withholding.
In an interview with Pharmacy Times, Joseph Rossano, MD, MS, FAAP, FACC, chief of cardiology at Children's Hospital of Philadelphia, discussed the treatment of adolescents with obstructive hypertrophic cardiomyopathy (oHCM), results of the phase 3 SCOUT-HCM trial (NCT06253221) of mavacamten (Camzyos; Bristol Myers Squibb), and the role pharmacists play as patients begin therapy. The discussion took place following the FDA’s
Rossano explained that before cardiac myosin inhibitors, medications available for adolescents with oHCM were aimed at symptom improvement and were not specific to the disease. Beta-blockers were most commonly used, followed by calcium channel blockers and, less often, disopyramide (Norpace; Pfizer), but their effects were modest, and many patients continued to have symptoms. Surgical myectomy was the only truly effective option.
In SCOUT-HCM, Rossano said, mavacamten produced a dramatic and sustained reduction in the primary end point, the Valsalva-provoked left ventricular outflow tract (LVOT) gradient, with most patients' obstruction falling below levels considered obstructive. The placebo group, most of whom were taking beta-blockers, showed essentially no change. Secondary and exploratory end points were consistent, including exercise gradients, echocardiographic measures such as diastolic dysfunction and mitral regurgitation, and biomarkers of cardiac injury and stress.
For pharmacists, Rossano highlighted 2 priorities. Mavacamten is part of a Risk Evaluation and Mitigation Strategy (REMS) program, and one of its potential risks is systolic dysfunction that could put patients at risk for heart failure. In addition, because certain medications can affect its metabolism and increase exposure, patients need to be screened for concomitant drugs that may require a mavacamten dose adjustment or withholding therapy.
Rossano described mavacamten as the first therapy for children with cardiomyopathy tailored to the disease's underlying pathophysiology. Still, he emphasized the need for long-term data and for studies in populations not included in the trial, such as younger children and patients with phenocopies, including Noonan syndrome and other RASopathies, who can have severe obstruction.
