September 2026

CARDIOVASCULAR

EXPERIMENTAL DRUG SHOWS POTENTIAL FOR HARD-TO-TREAT HEART DISEASE

Featuring: Lubna Choudhury, MD
An experimental drug has been shown to improve symptoms, exercise capacity and heart failure status in patients with an inherited heart disease, according to a pair of newly published studies. 

The studies, published in The New England Journal of Medicine and Circulation, evaluated aficamten, a next-generation cardiac myosin inhibitor, in patients with symptomatic nonobstructive hypertrophic cardiomyopathy, or nHCM. Myosin is a protein of the contractile unit of the heart muscle. 

Nonobstructive HCM (nHCM) makes up about 30 percent of people with hypertrophic cardiomyopathy, a genetic condition in which the heart muscle becomes abnormally thick and stiff. Patients often experience shortness of breath, exercise intolerance and reduced quality of life.  
​
In The New England Journal of Medicine study, investigators gave either aficamten or a placebo to 517 trial participants and found that the drug significantly improved patient-reported health status and exercise capacity compared to placebo. 

​The findings address a longstanding treatment gap, said Lubna Choudhury, MD, professor of Medicine in the Division of Cardiology and a co-author of both of the studies.  

“Until now, no specific treatments have been effective for nonobstructive HCM which has been treated empirically so far,” Choudhury said. “With these new studies, I can now recommend to patients a specific designer drug therapy which can work for them, make them feel better, and also improve their overall heart failure status.” 

One of the most notable findings involved peak oxygen consumption, or peak VO2, a measure of cardiovascular fitness and heart failure severity, Choudhury said. 

“This was a game changer, because that really shows we can impact these patients, not only in the way they feel, but objectively in the cardiac function that we’re measuring with the peak VO2,” she said.  

The companion Circulation study explored why patients improved. Investigators analyzed serial echocardiograms and found that aficamten altered heart structure and function. Compared with placebo, the drug improved several markers of diastolic function, the heart’s ability to relax and fill with blood between beats, while also reducing signs of excessive contraction that characterize HCM.  

​“This drug definitely reduces heart wall stress. It reduces the supernormal functioning of the muscle that we see in hypertrophic cardiomyopathy,” Choudhury said. “We saw indications from the Circulation paper that diastolic dysfunction parameters improve. That may explain why the patients feel better.”  

Investigators also reported improvements in tissue Doppler measurements of relaxation, changes in left ventricular blood volumes and reductions in markers of cardiac stress, suggesting the drug may be modifying the disease process rather than simply relieving symptoms.  

Choudhury said the two studies complement each other and provide a better understanding of the drug’s impacts. 

“One shows you the overall effect on the patients, how patients feel and their objective improvement, and the other shows you why they have improved,” she said.  
​
The findings build on earlier evidence that aficamten is effective in obstructive HCM, a more common form of the disease. The current trials were designed to determine whether those benefits could extend to patients without outflow tract obstruction, who historically have had no targeted treatment options.  

​Investigators are now following participants in an ongoing extension study examining the long-term effects of aficamten in both obstructive and nonobstructive HCM patients.  

“We want to get more long-term data on how these things look after several years in these patients,” Choudhury said. 

Cytokinetics, maker of aficamten, supported both studies. 

This article was originally published in the Feinberg School of Medicine News Center on September 15, 2026.
Lubna Choudhury, MD, professor of Medicine in the Division of Cardiology, was co-author of the studies.
​

Refer a Patient

Northwestern Medicine welcomes the opportunity to collaborate with you in caring for your patients. ​

You May Also Like