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SearchMedication, called mavacamten, has been previously shown to be effective in patients with obstructive hypertrophic cardiomyopathy
Imaging of non-obstructive hypertrophic cardiomyopathy
Findings from a Cleveland Clinic-led clinical trial showed that the use of the drug, mavacamten in symptomatic, non-obstructive hypertrophic cardiomyopathy patients did not significantly reduce symptoms compared to placebo.
Results from the phase III ODYSSEY-HCM trial were presented today during a late-breaking science session at the European Society of Cardiology meeting and simultaneously published in the New England Journal of Medicine.
The cardiac myosin inhibitor, mavacamten works by reducing excessive contraction of the heart muscle, making it work more efficiently. It also reduces the stiffness of the heart muscle. The medication was approved world-wide for the treatment of symptomatic obstructive hypertrophic cardiomyopathy following results from the Cleveland-Clinic-led VALOR-HCM Trial, which showed that the drug reduced or delayed the need for surgical intervention.
ODYSSEY-HCM set out to evaluate if mavacamten could improve symptoms and exercise capacity in non-obstructive hypertrophic cardiomyopathy patients.
The randomized, double-blind phase III trial enrolled 580 patients and was conducted at 201 sites in 22 countries. At 48 weeks, mavacamten demonstrated no statistically significant improvement over placebo. Both groups showed some symptom improvement, which may have reflected enhanced background care during the study.
There are two main types of hypertrophic cardiomyopathy. In obstructive hypertrophic cardiomyopathy, the thickened part of the heart muscle is in the septal wall, which divides the heart into the right side and left side. This blocks or reduces blood flow from the left ventricle to the aorta.
In the non-obstructive type, the heart muscle is thickened in other areas, such as the bottom of the heart, right ventricle or entire left ventricle, but this thickening doesn’t block blood flow out of the heart. About two in three people with hypertrophic cardiomyopathy in the United States have the obstructive type.
“While this drug was not associated with significant improvements in quality of life or peak oxygen consumption, these results help make it clear that obstructive hypertrophic cardiomyopathy and non-obstructive cardiomyopathy are two unique diseases,” said Milind Desai, M.D., MBA, Vice-Chair of Education and CME in Cleveland Clinic’s Heart Vascular & Thoracic Institute, and principal investigator of the trial.
“With non-obstructive hypertrophic cardiomyopathy, since different parts of the wall are thickened - patients tend to have more severe symptoms, compared to obstructive cardiomyopathy patients, Dr. Desai added. “Therefore it is not surprising that treatments may not work uniformly. These findings should push researchers to explore new targeted strategies for this patient group."
The cause of hypertrophic cardiomyopathy can be unknown or attributed to genetics, high blood pressure or aging, making it difficult to identify a high-risk population. Symptoms include chest pain, palpitations, shortness of breath, fatigue and syncope (fainting). Most people with hypertrophic cardiomyopathy have a low risk for sudden cardiac death; however, the condition is the most common cause of sudden cardiac death in people under age 30.
“Further analyses are being conducted to understand more about the effects of mavacamten in non-obstructive hypertrophic cardiomyopathy and whether any patient subgroups may benefit,” said Dr. Desai.
The trial was funded by MyoKardia, Inc, a wholly owned subsidiary of Bristol Myers Squibb (Brisbane, CA) and coordinated by Cleveland Clinic Coordinating Center for Clinical Research (C5Research).
Dr. Desai is a consultant for Bristol Myers Squibb and Medtronic. He serves on the scientific advisory board of Caristo Diagnostics.
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