The FDA has raised concerns about the efficacy of Capricor Therapeutics' stem cell treatment for Duchenne muscular dystrophy (DMD), known as deramiocel, contradicting the company's previous claims that it met its Phase 3 trial objectives. Capricor had reported that the drug successfully preserved upper-arm function and prevented heart failure in patients, primarily teenagers and young men who had lost the ability to walk. However, the FDA's statement indicates that the treatment did not fulfill the trial endpoints, casting doubt on its benefits for a condition that lacks effective treatment options.

Ahead of hearing, FDA questions the efficacy of Capricor’s Duchenne drug

Capricor had previously said its drug, called deramiocel, hit its targets in a Phase 3 study

Sarah Silbiger/Getty Images

By Jason Mast

July 27, 2026

General Assignment Reporter

Jason Mast

jason.mast@statnews.com

Jason is a general assignment reporter, with particular focus on genetic medicine and rare disease. Confidential tips can be sent on Signal at JasonMast.77.

The Food and Drug Administration said Monday that Capricor Therapeutics’ stem cell treatment for Duchenne muscular dystrophy did not meet the objectives of a Phase 3 trial — contrary to the company’s claims last year.

Capricor said in December that the drug, known as deramiocel, met both the primary and secondary endpoints in a large, randomized study. It was a striking result in a fatal, childhood disease that has proven stubbornly difficult to treat, despite immense advances in genetic medicine.

The data were also notable for coming primarily in teenagers and young men who have already lost the ability to walk, a population with few options. The drug appeared to both preserve their upper-arm function and stave off the heart failure most patients eventually experience, Capricor had said.

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Jason Mast

General Assignment Reporter

Jason is a general assignment reporter, with particular focus on genetic medicine and rare disease. Confidential tips can be sent on Signal at JasonMast.77.

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Ahead of hearing, FDA questions the efficacy of Capricor's Duchenne drug

Ahead of hearing, FDA questions the efficacy of Capricor’s Duchenne drug

Capricor had previously said its drug, called deramiocel, hit its targets in a Phase 3 study

This article is exclusive to STAT+ subscribers

Unlock this article — plus daily coverage and analysis of the biotech sector — by subscribing to STAT+.

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