The FDA has resumed review of Capricor Therapeutics’ previously rejected Duchenne muscular dystrophy cell therapy following the biotech’s submission of more clinical data, as well as the newly announced upcoming departure of Vinay Prasad, M.D.
The agency has “lifted” the complete response letter (CRL) that was issued for deramiocel in July 2025, Capricor said in a March 10 release, and an approval decision is now expected by Aug. 22.
Capricor’s response to the rejection was a class 2 resubmission (PDF), a more substantial type of response that goes beyond minor clarifications of data or tweaks to the medicine’s planned label, according to the release.
The biotech’s response included topline data from a phase 3 trial that showed treatment with deramiocel improved upper limb function and left ventricle ejection fraction, a Capricor spokesperson told Fierce. These data were followed up by a clinical study report (CSR) in February at the agency’s request.
“We are encouraged by the FDA’s acknowledgment of our response to the complete response letter and its continued review of our BLA for deramiocel,” Capricor CEO Linda Marbán, Ph.D., said in the release. “We believe the positive HOPE-3 results and broader clinical evidence reinforce deramiocel’s potential to become a first-in-class therapy for Duchenne muscular dystrophy, with the opportunity to address both skeletal and cardiac manifestations of the disease.”
CRLs typically mark the end of a new drug application’s lifecycle, per FDA guidelines, with a company’s response potentially sparking an appeal or new review process. Capricor’s description of deramiocel’s CRL as being “lifted” and the review resuming is highly unusual.
“Upon receipt and review of the HOPE-3 materials, including the CSR, the FDA determined there were no review issues that would prevent the application from moving forward,” the Capricor spokesperson said. “As a result, the agency has lifted the prior CRL and reinitiated review of our Biologics License Application.”
Deramiocel’s new review constitutes a “resubmission,” Andrew Nixon, spokesperson for the Department of Health and Human Services, told Fierce. A successful resubmission starts a new review cycle, according to FDA guidance.
Asked what the company means by calling the CRL “lifted,” Nixon deferred to Capricor.
When asked for more information, Capricor clarified with Fierce that “there was no special agreement or unusual process involved” in the resubmission.
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Capricor’s stock enjoyed a bump on the news of the FDA’s reconsideration, rising from $30.63 per share at yesterday’s close to $35.60 at 10:30 a.m. ET on March 10.
FDA’s rejection of deramiocel last summer came as a surprise to Capricor, which said it had previously agreed with the agency that its phase 2 trial would be sufficient to support approval. Instead, the regulator asked to see more clinical data, Capricor said at the time.
After the FDA kicked off a new policy of publicly releasing drug rejection letters, the agency’s issues with deramiocel became clearer. The agency wrote that the cell therapy had “failed to demonstrate efficacy for its prespecified primary efficacy endpoint” in the phase 2 trial.
Capricor disputed this assessment, writing in a release that the primary outcome was in fact met if the data were “analyzed with appropriate statistical techniques.”
The FDA’s initial rejection of deramiocel and the agency’s reported about-face fit a pattern that came to define the Center for Biologics Evaluation and Research under the now-exiting Prasad. As director, Prasad oversaw multiple rejections for rare disease therapies that came as surprises to their biotech sponsors, including a public dustup with gene therapy maker uniQure that may have contributed to Prasad’s upcoming departure.
Amid this tension, Wisconsin’s Republican Senator Ron Johnson has declared his intent to investigate the FDA’s rare disease rejections, calling the agency’s request for uniQure to conduct a new clinical trial “bureaucratic idiocy.”
Editor’s note: This story was updated at 12:30 p.m. and 1:15 p.m. ET with comment from Capricor and HHS.
