07:17 AM EDT, 07/11/2025 (MT Newswires) -- Capricor Therapeutics ( CAPR ) said Friday that the US Food and Drug Administration has required additional clinical data on deramiocel, a cell therapy candidate for cardiomyopathy in Duchenne muscular dystrophy patients.

The company said it received FDA's complete response letter, saying the agency had completed its review of Capricor's biologics license application for deramiocel but found this to be lacking "substantial evidence of effectiveness."

The letter also mentioned unresolved issues in the chemistry, manufacturing, and controls section of the application, the company said, adding that it had already addressed many of these in prior submissions. However, it added that the agency did not review those materials due to the timing of the complete response letter.

Capricor said the FDA has offered a type A meeting to discuss the path forward, and the company intends to engage with the agency to determine the next steps.

Capricor's shares were falling more than 49% in recent premarket activity Friday.