Last week, the U.S. Food and Drug Administration approved the use of mavacamten, an oral medication to treat a rare heart condition called obstructive hypertrophic cardiomyopathy (oHCM).
Mavacamten, sold under the brand name Camzyos by New York-based pharmaceutical giant Bristol Myers Squibb, is the first cardiac myosin inhibitor approved by the FDA. The new drug will be sold as capsules, ranging in dosage from 2.5 mg to 15 mg.
oHCM, the disease mavacamten is approved to treat, is related to hypertrophic cardiomyopathy, a common genetic heart condition where the heart’s walls are thicker than usual. According to the Mayo Clinic, this condition often exhibits no symptoms and goes undiagnosed. However, oHCM is a result of the heart’s thickened walls obstructing blood flow throughout the body, which can result in symptoms like heart palpitations, difficulty with physical activity, and shortness of breath. The most serious cases of oHCM can be life-threatening.
oHCM is a result of the heart’s thickened walls obstructing blood flow throughout the body, which can result in symptoms like heart palpitations, difficulty with physical activity, and shortness of breath.
Mavacamten is a cardiac myosin inhibitor, a type of drug that reduces the force with which the heart contracts. Myosin inhibitors, according to 2021 research published in Cardiology Research, work by decreasing the amount of myosin (a protein key to muscle contractions) that reaches the heart muscles, thereby slowing an enzyme cycle and decreasing the pressure with which the muscle contracts.
Mavacamten is approved to treat class II-III oHCM in the four-level New York Heart Association Functional Classification scale. Generally, this means the drug is intended to treat patients whose physical activity is limited or triggers symptoms but who do not experience any trouble at rest.
…the drug is intended to treat patients whose physical activity is limited or triggers symptoms but who do not experience any trouble at rest.
Analysis of diagnosed HCM cases shows the prevalence of oHCM in the U.S. to be approximately 1.65 per 10,000, or about 1 in 6,000, according to research published in Frontiers in Cardiovascular Medicine. The risk of oHCM increases with age.
In pre-approval phase 3 trials, mavacamten was found to significantly improve symptoms and quality of life in patients receiving the medication using the Kansas City Cardiomyopathy Questionnaire. The results of these trials were published last year in The Lancet.
“Mavacamten markedly improved the health status of patients with symptomatic obstructive hypertrophic cardiomyopathy compared with placebo, with a low number needed to treat for marked improvement,” reads the summary of the findings. “Given that the primary goals of treatment are to improve symptoms, physical and social function, and quality of life, mavacamten represents a new potential strategy for achieving these goals.”
Given that the primary goals of treatment are to improve symptoms, physical and social function, and quality of life, mavacamten represents a new potential strategy for achieving these goals
In a statement from Bristol Myers Squibb, Milind Desai, MD, director of the Hypertrophic Cardiomyopathy Center, said the treatment attacks the root of oHCM instead of simply treating symptoms.
“This is a first-in-class medicine specifically for patients living with symptomatic obstructive HCM,” Desai said in the statement. “With this FDA approval, U.S. cardiologists now have a new pharmacological option for eligible patients that targets the underlying pathophysiology of the disease.”
The new medication could end up being expensive: The wholesale acquisition cost for a single pill is almost $250 and the annual price tag for treatment is listed as $89,500, according to figures Bristol Myers Squibb provided to Reuters.