An investigational cell therapy slowed the loss of arm and elbow function in boys and young men with advanced Duchenne muscular dystrophy (DMD), according to Phase 3 results published as U.S. regulators weigh whether to approve it.
The therapy, deramiocel, developed by Capricor Therapeutics, uses allogeneic (donor-derived) cardiosphere-derived cells — a cell population originally isolated from heart tissue. In the HOPE-3 trial, 106 boys and young men aged 10 to 22 were randomized to deramiocel (54) or placebo (52) and given intravenous infusions every three months for one year across 20 U.S. sites.
What the trial showed
On measures of upper-limb function, decline was 54% slower for arm movement and 65% slower for elbow movement with deramiocel than with placebo. Because Duchenne progressively robs patients of muscle strength, slowing that decline in the arms — which patients rely on as walking becomes difficult — is clinically meaningful.
The heart data are less clear
DMD also damages the heart, and deramiocel was first studied for cardiac effects. Here the results were mixed: there was no clear overall difference in heart function between groups. In a subgroup of 64 participants with existing heart disease, deramiocel was associated with better preservation of function, and 22 participants showed less spread of heart scarring — findings the researchers say require further confirmation.
Safety
No deaths were reported. Allergic-type reactions were more common with deramiocel (42%) than placebo (15%), but most side effects were mild to moderate and resolved within one to two days; common events included headache, cough, fever, nausea and rapid heartbeat.
Why it matters now
The results were published on July 29, the same day an FDA advisory committee met to review the therapy. A decision from the agency is expected by August 22, 2026. For families facing a relentless disease with few options, an approval would add a new tool — though the modest, region-specific benefits underline how incremental progress in DMD remains.