Deramiocel Significantly Slows Upper Limb Function Decline in Advanced Duchenne Muscular Dystrophy: Phase 3 HOPE-3 Trial Published in The Lancet

Investigators have reported positive results from the pivotal Phase 3 HOPE-3 trial demonstrating that deramiocel, an investigational allogeneic cardiosphere-derived cell therapy, significantly slowed upper-limb functional decline in patients with advanced Duchenne muscular dystrophy (DMD) while maintaining a manageable safety profile.

The peer-reviewed findings, published in The Lancet, provide independent external validation of the trial design, statistical methodology, and efficacy results that support Capricor Therapeutics’ Biologics License Application (BLA), which remains under active review by the US Food and Drug Administration (FDA) with a Prescription Drug User Fee Act (PDUFA) target action date of August 22, 2026.

Duchenne muscular dystrophy is a severe X-linked genetic disorder caused by the absence of functional dystrophin, resulting in progressive degeneration of skeletal, respiratory, and cardiac muscle. Although corticosteroids and mutation-specific therapies have improved outcomes in selected patients, treatment options remain limited for individuals with late-ambulatory and non-ambulatory disease. Cardiomyopathy is the leading cause of death, highlighting the need for therapies that preserve both skeletal and cardiac muscle function.

HOPE-3 Trial Demonstrates Significant Functional Benefit

Study Design and Treatment Overview

Deramiocel is an intravenously administered, heart-derived allogeneic cardiosphere-derived cell (CDC) therapy designed to exert immunomodulatory and anti-fibrotic effects through secretion of extracellular vesicles (exosomes) that alter macrophage activity toward a tissue-healing phenotype. Unlike mutation-specific therapies, deramiocel aims to preserve skeletal and cardiac muscle function regardless of the underlying dystrophin mutation.

The multicentre, randomised, double-blind, placebo-controlled Phase 3 HOPE-3 trial (NCT05126758) enrolled 106 males aged 10 years or older with genetically confirmed DMD who either late-ambulatory or non-ambulatory with preserved upper-limb function across 20 centres in the United States were. Participants were randomised 1:1 to receive deramiocel (n=54) or placebo (n=52) by outpatient intravenous infusion every three months for 12 months. The primary endpoint evaluated percentage change from baseline in Performance of the Upper Limb 2.0 (PUL2.0), while the key secondary endpoint assessed left ventricular ejection fraction (LVEF) by cardiac magnetic resonance imaging (MRI). 

Primary and Secondary Efficacy Results

At 12 months, deramiocel met the primary efficacy endpoint, significantly slowing the decline in upper-limb function compared with placebo. The adjusted between-group least-squares mean difference in percentage change from baseline in PUL2.0 was 4.55% (95% CI: 0.47-8.63; p=0.029), corresponding to an estimated 54% slowing of disease progression and a clinically meaningful 1.2-point advantage on the PUL2.0 scale. Preservation of upper-limb function may help patients maintain independence in essential activities such as self-feeding, transferring, and turning, thereby supporting quality of life as the disease progresses.

Although the key secondary endpoint of LVEF did not reach statistical significance (p=0.0935), subsequent analyses consistently favoured deramiocel. Nominally significant improvements were observed in mid-level PUL2.0, representing an estimated 65% slowing of disease progression, as well as in late gadolinium enhancement (LGE) and the Total Global Statistical Test. Because the prespecified hierarchical testing sequence was not completed after the LVEF endpoint narrowly missed significance, these subsequent findings should be interpreted as supportive rather than confirmatory. Investigators also reported favourable LVEF trends in participants with baseline cardiomyopathy, suggesting potential cardioprotective effects that warrant confirmation through longer-term follow-up.

Safety Profile Supports Repeated Administration

Deramiocel demonstrated a manageable safety profile over 12 months of treatment. Most treatment-emergent adverse events were mild or moderate in severity. Hypersensitivity reactions occurred more frequently with deramiocel than placebo but were generally manageable with premedication and medical supervision, while serious adverse events were uncommon and occurred more frequently in the placebo group. No new safety signals, immune sensitisation syndrome, acute respiratory decompensation, or treatment-related mortality were identified. The feasibility of quarterly outpatient intravenous administration further supports the potential for long-term treatment in patients with advanced DMD.

Clinical Perspective

The HOPE-3 findings represent an important advance in the treatment landscape for advanced DMD. Unlike exon-skipping therapies that target specific dystrophin mutations, deramiocel demonstrated clinical benefit irrespective of genotype, potentially expanding treatment eligibility across a broader DMD population. Slowing upper-limb functional decline is clinically meaningful because it may help preserve independence in essential daily activities, while the consistent cardiac findings across multiple imaging and functional measures support the therapy’s potential to modify disease progression. Although the primary cardiac endpoint narrowly missed statistical significance, the overall pattern of benefit provides encouraging evidence for continued long-term evaluation.

What This Results Means

Publication of the HOPE-3 trial in The Lancet provides independent peer-reviewed validation of the study design, statistical analysis plan, and clinical findings, strengthening the evidence supporting deramiocel. These results form a key component of Capricor Therapeutics’ BLA currently under FDA review, with a PDUFA target action date of August 22, 2026.

If approved, deramiocel could become the first approved cell therapy for Duchenne muscular dystrophy and the first mutation-independent cell therapy for patients with advanced disease. Beyond its potential impact on DMD, the HOPE-3 trial represents an important milestone for regenerative medicine by demonstrating Phase 3 efficacy of a manufactured cell therapy in a genetic disease, potentially paving the way for future cell-based therapies targeting inherited disorders.

Reference

The Lancet Publishes HOPE-3 Data for Capricor Therapeutics’ Deramiocel in Duchenne Muscular Dystrophy :: Capricor Therapeutics, Inc. (CAPR)

Deramiocel heart-derived cellular therapy in advanced Duchenne muscular dystrophy (HOPE-3): a phase 3, randomised, double-blind, placebo-controlled trial