Capricor Therapeutics, a biotechnology company developing cell and exosome-based therapeutics for rare diseases, announced that it has received a Complete Response Letter (CRL) from the U.S. Food and Drug Administration (FDA) regarding its Biologics License Application (BLA) for Deramiocel, the company’s lead cell therapy candidate for cardiomyopathy associated with Duchenne muscular dystrophy (DMD).

In the CRL, the FDA stated that it has completed its review of the application but cannot approve the BLA in its current form. The agency cited the need for additional clinical data, noting that the submission does not meet the requirement for substantial evidence of effectiveness. The CRL also mentioned outstanding items in the Chemistry, Manufacturing, and Controls (CMC) section. Capricor believes most of these issues were addressed in previous communications, but the FDA did not review these materials due to the timing of the CRL issuance.

The FDA confirmed it will restart the review process upon resubmission and has offered Capricor the option to request a Type A meeting to discuss the next steps. Capricor plans to engage further with the FDA to determine the path forward.

Capricor’s BLA for Deramiocel received Priority Review in March 2025. The submission was supported by data from the HOPE-2 trial, its open-label extension (OLE), and natural history comparisons from FDA-funded datasets.

“We are surprised by this decision from the FDA. We have followed their guidance throughout the process,” said Linda Marbán, Ph.D., CEO of Capricor. “Before the CRL, the review had progressed without major issues, including a successful pre-licensure inspection and completion of the mid-cycle review.”

Capricor plans to submit additional data from the ongoing Phase 3 HOPE-3 clinical trial, a randomized, double-blind, placebo-controlled study of 104 patients. Topline results are expected in the third quarter of 2025. The company believes these results, if positive, along with existing long-term data showing cardiac stabilization, preservation of skeletal muscle function, and a consistent safety profile, could help address the FDA’s questions.

“While this was an unexpected decision, we remain committed to the DMD community and will work to advance Deramiocel through the approval process,” added Dr. Marbán.