Investigational heart drug for nonobstructive HCM one step closer to FDA approval
Ninerafaxstat, an investigational oral therapy developed by Imbria Pharmaceuticals, may be on its way to becoming the first U.S. Food and Drug Administration (FDA)-approved drug for the treatment of symptomatic nonobstructive hypertrophic cardiomyopathy (nHCM).
Imbria Pharmaceuticals announced that ninerafaxstat has officially received the FDA’s orphan drug designation. This means the company now has access to certain benefits—including tax credits and fee exemptions—designed to help with the drug’s development. In addition, the drug could potentially secure seven years of market exclusivity if it does go on to receive FDA approval for the treatment of symptomatic nHCM.
“Receiving Orphan Drug Designation for ninerafaxstat is an important milestone as we advance its development for patients living with symptomatic nHCM, a population with significant unmet medical need,” Alvin Shih, MD, CEO of Imbria Pharmaceuticals, said in a statement. “Despite recent progress in HCM, there are still no approved therapies for nHCM, and patients continue to experience debilitating symptoms, including shortness of breath, fatigue and exercise intolerance. By improving cardiac energetics, ninerafaxstat represents a differentiated approach to addressing nHCM, with the potential to be used as a standalone therapy or in combination with other treatments.”
Key research now underway
The safety and effectiveness of ninerafaxstat is currently being evaluated in the ongoing FORTITUDE-HCM clinical trial, a randomized study comparing the drug to a placebo. The study's primary endpoint is a change from baseline in the Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score.
In 2025, Imbria Pharmaceuticals announced it had partnered with the Hypertrophic Cardiomyopathy Association (HCMA) to ramp up patient recruitment for FORTITUDE-HCM.
“Every step forward in clinical research brings us closer to improving the lives of those living with nHCM,” Lisa Salberg, founder and CEO of HCMA, said at the time. “By supporting patient recruitment for FORTITUDE-HCM and spotlighting this collaboration at our annual meeting, we aim to increase awareness of this potential treatment and connect patients and families with meaningful opportunities to advance research and improve care.”
Imbria Pharmaceuticals hopes to share early data from FORTITUDE-HCM in the first half of 2027.
Michael has more than 19 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.