Capricor Therapeutics has bounced back from a bruising FDA advisory committee meeting by securing a green light to file an amendment to its approval application, raising hopes that the biotech can rescue its Duchenne muscular dystrophy (DMD) cell therapy. The biotech’s stock soared following the news.
The advisory committee voted nine to three against the efficacy of the cell therapy, deramiocel, for the treatment of cardiomyopathy associated with DMD. However, Hope-3, the trial that enabled Capricor to refile for FDA approval after last year’s rejection, only measured deramiocel’s effect on cardiomyopathy as a secondary endpoint. The trial’s primary endpoint looked at upper-limb function.
Capricor plans to file an amendment to its approval application to “support a refined indication focused on the primary endpoint,” CEO Linda Marbán, Ph.D., said on the company’s earnings call after the market closed Thursday.
The FDA has indicated it is willing to review the amendment, which will include 24-month results from the open-label extension to Hope-3 and additional analyses on the existing data, Marbán said. Capricor is finalizing the timing of the submission and expects the FDA to extend the PDUFA action date after receiving the amendment. The FDA is currently scheduled to rule on the existing filing by Aug. 22.
If Capricor secures a later PDUFA date for a new indication, attention will turn to whether it can make a stronger case for the effect of deramiocel on upper limb function than on cardiomyopathy. The advisory committee’s discussion of deramiocel’s effect on upper limb function “was directionally supportive of the clinical evidence,” Marbán said.
The recording of the meeting showed some experts had doubts about the upper limb data.
“There might be something here,” Steven Pavlakis, M.D., a professor of neurology at SUNY Downstate Health Sciences University, said, but “the data that we have is very fragile ... and it’s very hard to say that there is a real effect in terms of muscle strength.”
Christopher Coffey, Ph.D., a biostatistician at the University of Iowa College of Public Health, said in the meeting that he was “not convinced there’s a benefit in upper limb, but I feel stronger that there might be something there for upper limb than I do for the [left ventricular ejection fraction].”
The efficacy signal, coupled to “compelling testimony” from patients’ families, led the National Institutes of Health’s Cynthia Tifft, M.D., Ph.D., to speculate that “if it was a bigger study, if it went for longer, if we chose different endpoints, that there probably is something there.” Tifft, Coffey and Pavlakis voted no to the cardiomyopathy question.
Capricor now faces a wait to learn whether longer-term data, centered on a different endpoint, can get the FDA to approve deramiocel.
Investors sent Capricor’s share price up 71% to $7.19 when the markets opened Friday from a Thursday closing price of $4.21. Even so, the stock still trades well below the price it commanded before the advisory committee vote, when Capricor’s shares sold for about $20.