By Christy Santhosh and Sahil Pandey
July 27 (Reuters) – U.S. Food and Drug Administration staff reviewers raised concerns about the effectiveness data for Capricor Therapeutics’ cell therapy for a heart condition related to Duchenne muscular dystrophy, dragging the company’s shares 70% lower in early trading.
The briefing documents, released on Monday, raise concerns for the treatment at the FDA’s external advisers’ meeting on Wednesday, where the effectiveness and risk-benefit profile of the experimental therapy, deramiocel, will be discussed.
The agency’s staff said that Capricor changed how it measured the main results after the therapy’s late-stage trial ended, calculating arm-function performance as a percentage change instead of the original plan of analyzing scores in a 42-point test.
Measurement of heart function was also changed to ranking patients’ results, from monitoring changes in the percentage of blood pumped by the heart with each beat, which in medical terms is called left ventricular ejection fraction, the reviewers said in their briefing document.
“FDA does not consider the conversion of raw change to percent change and then back to raw change to have been scientifically justified, as it adds complexity and reduces accuracy,” the agency’s staff said in their briefing document.
The reviewers also questioned whether the trial population had DMD-related cardiomyopathy, noting that patients had normal heart-pumping function on average at the outset.
Evidence was limited that enough of the intravenously delivered therapy reached the heart to provide a benefit, they added.
Duchenne muscular dystrophy, or DMD, is a rare inherited disease that causes progressive muscle weakness and primarily affects boys.
There are currently no FDA-approved therapies specifically for DMD-associated cardiomyopathy, a form of heart disease that commonly develops as the disease progresses.
Existing Duchenne treatments, including Sarepta Therapeutics’ gene therapy Elevidys and exon-skipping drugs, target the underlying cause of the disease rather than the heart complications that develop as patients age.
(Reporting by Sahil Pandey and Christy Santhosh in Bengaluru; Editing by Devika Syamnath and Leroy Leo)
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