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

The U.S. Food and Drug Administration raised concerns over the effectiveness of Capricor Therapeutics' stem cell therapy for Duchenne muscular dystrophy ahead of a regulatory review. In a statement released Monday, the agency noted that the Phase 3 clinical trial results for the treatment, named deramiocel, failed to meet its predefined goals. This contradicts earlier assertions made by the biotechnology firm, which claimed success in a pivotal study conducted in late 2025. Capricor announced in December 2025 that deramiocel demonstrated positive outcomes in a large, randomized trial involving patients with Duchenne muscular dystrophy. According to the company, the treatment achieved both primary and secondary endpoints, marking a significant breakthrough in treating a condition that currently lacks effective therapeutic options. The trial focused on adolescents and young adults who had already lost mobility due to the progressive muscle-wasting disorder. Duchenne muscular dystrophy is a severe, inherited disease that leads to loss of muscle strength and eventual respiratory and cardiac failure. Despite advancements in gene therapy and other treatments, there remains a critical need for interventions that can slow disease progression and improve quality of life. Capricor's claim that deramiocel preserved upper-arm function and delayed heart failure in participants was presented as a major step forward in the field. The FDA’s recent assessment suggests that the evidence supporting these claims may not be robust enough to warrant approval. While the agency acknowledged the difficulty of developing therapies for Duchenne, it emphasized that the trial data did not align with the standards required for regulatory clearance. The discrepancy between Capricor’s findings and the FDA’s evaluation highlights the rigorous nature of the approval process for novel treatments. The trial included a diverse group of patients, predominantly male adolescents and young adults, many of whom had advanced stages of the disease. These individuals typically face limited treatment options, making the potential success of deramiocel particularly noteworthy. However, the FDA’s skepticism underscores the importance of methodological rigor in clinical trials, especially for conditions with high mortality rates and limited therapeutic alternatives. Capricor Therapeutics, based in California, has been actively pursuing regulatory pathways for deramiocel. The company has previously filed for accelerated approval and engaged in discussions with the FDA regarding the drug’s potential benefits. The upcoming regulatory hearing will provide further insight into how the agency intends to address the discrepancies in the trial data. Investors and medical professionals alike will be watching closely as the outcome could influence future treatment strategies for Duchenne muscular dystrophy.