MDA 2026: FDA decision on deramiocel for DMD expected by August
Latest trial shows therapy continues to slow progression of heart, arm damage
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The latest Phase 3 trial results continue showing that deramiocel, an investigational cell therapy for heart disease related to Duchenne muscular dystrophy (DMD), significantly slows the progression of arm and heart damage in boys and men with DMD.
Based on the positive Phase 3 results, Capricor Therapeutics has resubmitted an application for U.S. approval of deramiocel. The U.S. Food and Drug Administration is expected to make a decision by Aug. 22.
In 2025, the FDA declined to approve deramiocel, asking the company for additional data supporting deramiocel’s efficacy. The company reapplied, including results from the Phase 3 HOPE-3 study (NCT05126758) in the new submission.
Linda Marbán, PhD, is the CEO of Capricor Therapeutics (Photo by Kellie Benn)
“We gave them not only what they wanted, but we gave them more,” Linda Marbán, PhD, the CEO of Capricor, told Muscular Dystrophy News Today in an interview at the Muscular Dystrophy Association‘s 2026 Clinical & Scientific Conference, held last week in Orlando, Florida.
If approved, deramiocel would be the first therapy available for DMD-related cardiomiopathy, a form of heart disease that is a leading cause of death in Duchenne. The acknowledgment of cardiomiopathy as a major component of disease in Duchenne “really is a milestone for the field,” Marbán said. “This would be the first time that a prescription could be written to address the heart disease implications [of DMD].”
Top-line HOPE-3 results showed that deramiocel safely improved heart and arm muscle function over one year relative to a placebo.
At the MDA Conference, Craig McDonald, MD, a professor in the Departments of Pediatrics and Physical Medicine & Rehabilitation at UC Davis Health, presented further HOPE-3 data supporting the slower progression of upper limb and heart health damage with deramiocel. The oral talk was titled “Confirmation of musculoskeletal and cardiac benefit in DMD from deramiocel, an allogeneic cell therapy, in the Phase 3 HOPE-3 study.”
Deramiocel is a cell-based therapy for cardiac involvement in DMD
DMD is a genetic disorder that causes progressive muscle weakness and wasting. Mutations in the DMD gene result in virtually no dystrophin, a protein that helps protect muscle cells from damage.
In addition to skeletal muscles — the muscles that drive movement — Duchenne can also affect the muscles of the heart, which pump blood throughout the body.
“Cardiomyopathy associated with DMD is not your standard heart disease that you’re going to see after a heart attack or some other viral process,” Marbán noted. “It’s a very unique pathophysiology [disease process].”
Deramiocel is a cell-based therapy for cardiac involvement in DMD. It is created from specialized cells in human donor hearts, which are isolated, grown, and delivered to patients via infusion. Once in the body, the cells release tiny particles called exosomes that are taken up by immune cells called macrophages.
Macrophages “can either be angry in the sense that they’re trying to clear a pathogen, or dangerous invader, or … they can be healing, where they actually help the body repair itself,” Marbán said. Deramiocel aims to drive the macrophages into healing mode, she added.
Phase 3 trial met main goal
Capricor originally applied for FDA approval of deramiocel based primarily on findings from the Phase 2 HOPE-2 trial (NCT03406780) and the HOPE-2 open-label extension (NCT04428476). These studies showed that deramiocel improved heart and arm function in boys and young men with relatively advanced DMD over at least three years.
HOPE-3, the subsequent trial, included 106 participants with DMD, all male and at least 10 years old, who were on stable corticosteroid treatment. They were either late ambulatory, which means they were predicted to be unable to walk in two years, or were already unable to walk. They randomly received infusions of either deramiocel or a placebo every three months for one year.
The Phase 3 trial found that deramiocel was well tolerated, and most side effects were mild or moderate. While participants often didn’t experience side effects after their first infusion, many had mild flu-like symptoms after subsequent doses.
“This is exactly what you want to see, because that means that the immune system is going into … repair mode,” Marbán said. Over-the-counter medications like Tylenol or ibuprofen helped the patients get back to normal, she added.
Regarding efficacy, HOPE-3 showed that deramiocel improved a measure of arm and hand function called the Performance of Upper Limb (PUL 2.0) score, which was the trial’s main goal. Top-line results showed that the cell-based therapy eased PUL 2.0 score decline by 54% compared with placebo.
The PUL 2.0 metric, Marbán explained, is broken down into three major levels. Data presented at the MDA Conference further showed a 65% slowing of disease progression favoring deramiocel at mid-level, which corresponds to the elbow region.
According to Marbán, mid-level PUL 2.0 “is the best in terms of being able to measure clinical progression” and “is the ability to do things like drink your coffee, feed yourself, go to the bathroom, brush your hair, hug your family members, play with your smartphone, do all kinds of activities that are super important to maintain independence.”
Starting deramiocel early could help patients get most from therapy
Changes in left ventricular ejection fraction (LVEF), which measures how well the main pumping chamber of the heart is working, were a key secondary measure. Results showed a 91% slowing of heart function decline with deramiocel, which means near complete stabilization of LVEF as measured by cardiac MRI, McDonald said.
The difference was even more pronounced for participants who started the trial with abnormal LVEF or with evidence of fibrosis (scarring) in the heart, indicating cardiomyopathy. In this subgroup, LVEF actually improved slightly relative to study start.
“The cautionary tale here is that once they get below 35% of [LVEF] … they’ve lost so much heart muscle, there’s not much to pull back. And so we don’t see them do as well, in general, as a group,” Marbán said. However, “there are individuals that do well, and we would not discourage people who have poor cardiac function to try it,” she added.
This suggests that starting deramiocel early could help participants get the most from the therapy. Careful cardiac monitoring for DMD patients could help identify early signs of cardiomyopathy, such as scarring in the heart.
“What the cardiologists are excited about is if they see scar in the hearts of these guys on MRI when they’re young, we can get them on deramiocel right away, and that should be able to attenuate the damage,” Marbán said.
It’s a slower progressing disease, but the heart disease can be quite severe. It typically is what takes the life of these men with Becker, so we really feel like it’s our responsibility to get [deramiocel] to them as well.
The study also used the Duchenne Video Assessment, which allows caregivers to capture changes in motor abilities at home. The idea for this metric first came from mothers of Duchenne patients, Marbán said.
“For decades, we talked about white coat hypertension in adults, right? Nobody likes going to the doctor. So who wants to sit in a cold, you know, laboratory and raise your arm or whatever,” she added.
For HOPE-3, trained caregivers filmed arm and hand motion in the eat 10 bites task. The decline in this ability tracked closely with the decline in mid-level PUL score — and deramiocel slowed the loss of function for both.
“We saw statistically significant improvement in the Duchenne video assessment, so correlating beautifully with the data from the performance of the upper limb,” Marbán added. “This idea that you can also see improvement at home … is really quite critical to understanding that we are attenuating disease progression.”
Beyond Duchenne, Capricor hopes to begin testing the medication for cardiomyopathy in related diseases, such as Becker muscular dystrophy.
“It’s a slower-progressing disease, but the heart disease can be quite severe. It typically is what takes the life of these men with Becker, so we really feel like it’s our responsibility to get [deramiocel] to them as well,” Marbán said.
Note: The Muscular Dystrophy News Today team is providing live coverage of the 2026 MDA Clinical & Scientific Conference, held March 8-11 in Orlando, Florida. Go here to see the latest stories from the conference.
