• Posted May 17, 2024

Experimental Drug Helps Folks Battling Enlarged Heart Move More

An experimental drug can help patients better live with a genetic condition that causes the heart to enlarge and thicken, a new clinical trial shows.

People with the condition, hypertrophic cardiomyopathy (HCM), were able to take in and use significantly more oxygen while exercising after taking the drug aficamten, researchers reported May 15 in the New England Journal of Medicine.

"By having more oxygen available during exercise, patients with obstructive hypertrophic cardiomyopathy can more easily walk, perform household chores and do other everyday tasks,"said researcher Dr. Ahmad Masri, director of the Oregon Health & Science University's Hypertrophic Cardiomyopathy Center.

HCM affects about one in 500 people, and is one of the most common causes of sudden death for young people and otherwise healthy athletes, researchers said in background notes.

The genetic condition thickens the heart, making it difficult for the heart to pump effectively. As a result, people suffer from shortness of breath.

Aficamten is a pill that works by blocking the action of myosin, a family of proteins that are key to muscle contractions.

By having "fewer hands on the rope,"the drug appears capable of reversing and reducing thickening and stiffening of the heart, the drug's maker, Cytokinetics, says on its website. Cytokinetics funded the clinical trial.

The clinical trial of aficamten involved 282 adults with HCM, half of whom were given the drug and the other half a placebo.

Those who took aficamten had a significant increase in their maximum oxygen use while on a treadmill or exercise bike.

Increased peak oxygen uptake can improve a patient's ability to be physically active, while declining oxygen uptake can increase the risk of heart failure, death or requiring a heart transplant, researchers said.

These results follow the 2022 FDA approval of mavacamten as the first drug designed to treat the underlying cause of HCM, researchers said. 

Mavacamten has some drawbacks -- it can increase the risk of heart failure and interacts with several commonly used medications, researchers said. As a result, patients taking mavacamten must be closely monitored by their doctors.

Non-drug treatment options for HCM include surgery to remove excess heart muscle, researchers said.

"This is an exciting time for treating HCM,"Masri said in a university news 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."

Researchers also presented the findings at the European Society of Cardiology's Heart Failure meeting in Lisbon, Portugal.

More information

The American Heart Association has more about hypertrophic cardiomyopathy.

SOURCE: Oregon Health & Science University, news release, May 13, 2024