Patients with hypertrophic cardiomyopathy experienced a 1.7 mL/kg/min increase in peak oxygen uptake during exercise after taking the drug candidate.

Summary: A clinical trial found that an investigational drug significantly improved exercise capacity in patients with hypertrophic cardiomyopathy by increasing their peak oxygen uptake by 1.7 mL/kg/min. The study, published in the New England Journal of Medicine, involved 282 adults. Hypertrophic cardiomyopathy, a common heart condition affecting 1 in 500 people, thickens heart muscles and reduces blood flow. The new drug could offer a promising treatment, improving patients’ ability to perform everyday activities and reducing the risk of heart failure.

Key Takeaways:

  • The investigational drug increased peak oxygen uptake by 1.7 mL/kg/min in patients with hypertrophic cardiomyopathy, enhancing their ability to exercise and perform daily activities.
  •  Hypertrophic cardiomyopathy affects about 1 in 500 people, causing thickened heart muscles, reduced blood flow, shortness of breath, and an increased risk of sudden death in youth and athletes.
  • The clinical trial’s positive results suggest that the new drug could be a valuable treatment for hypertrophic cardiomyopathy, offering an alternative to existing therapies like surgery and other medications.

People with hypertrophic cardiomyopathy, a common heart condition, were able to use significantly more oxygen while exercising after taking an investigational drug in an international clinical trial, according to a study in the New England Journal of Medicine

The finding was also presented at the European Society of Cardiology’s Heart Failure 2024 meeting in Lisbon, Portugal.

Oregon Health & Science University (OHSU) is part of the randomized, double-blind phase 3 trial that is evaluating the experimental drug aficamten, which was developed by Cytokinetics to treat the obstructive form of hypertrophic cardiomyopathy. Of the 282 adults participating in the trial, 19 enrolled through OHSU, the most of any trial center.

Benefits of Increased Oxygen Availability

“By having more oxygen available during exercise, patients with obstructive hypertrophic cardiomyopathy can more easily walk, perform household chores, and do other everyday tasks,” says cardiologist Ahmad Masri, MD, MS, who co-wrote the paper and directs the OHSU Knight Cardiovascular Institute’s Hypertrophic Cardiomyopathy Center, in a release. “Our latest clinical trial results suggest aficamten is a promising treatment for HCM (hypertrophic cardiomyopathy).”

Hypertrophic cardiomyopathy affects about 1 in 500 people and is one of the most common causes of sudden death for youth and otherwise healthy athletes. Often caused by inherited gene mutations, it thickens heart muscles and makes it difficult for the heart to work as it should. It causes shortness of breath and reduces people’s ability to exercise. The obstructive form of hypertrophic cardiomyopathy reduces blood flow out of the heart.

Clinical Trial Methodology and Results

About half of the trial’s participants were given the experimental drug, and the other half took a placebo and served as the study’s control group. Scientists measured the participants’ oxygen levels while they used treadmills or bicycles. Those who took aficamten had a significant increase in their maximum oxygen use—1.7 milliliters per kilogram per minute more than those in the control group. 

Having an increased peak oxygen uptake can improve a patient’s ability to be physically active, whereas reduced oxygen uptake can increase the risk of experiencing heart failure, needing a heart transplant, and dying.

Non-Drug Treatment Options and Ongoing Research

Non-drug treatment options for obstructive hypertrophic cardiomyopathy include surgery to remove excess heart muscle. In 2022, the Food and Drug Administration also approved mavacamten as the first drug designed to target the underlying cause of obstructive hypertrophic cardiomyopathy. However, mavacamten may increase the risk of heart failure and it interacts with several commonly used medications. As a result, patients who use mavacamten must also undergo intense monitoring.

During the past decade, OHSU has been involved in many research studies exploring new hypertrophic cardiomyopathy treatment options. It has been a center for several mavacamten studies and is participating in gene therapy research. The university is also currently involved in four other aficamten trials that are evaluating it as a potential treatment for various forms of hypertrophic cardiomyopathy and in different types of patients, including children.

“This is an exciting time for treating HCM (hypertrophic cardiomyopathy),” Masri says in a release. “While we continue to offer traditional surgical and procedural therapies for HCM, we are now also able to offer patients other treatment options: therapies that were recently approved by the FDA and investigational therapies that are available by participating in clinical trials.”

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