Safety, Tolerability, Pharmacodynamic, Efficacy, and Pharmacokinetic Study of DYNE-251 in Participants With Duchenne Muscular Dystrophy Amenable to Exon 51 Skipping

Running, not enrolling · Phase 1/Phase 2 · Has a placebo group

Conditions studied: Duchenne Muscular Dystrophy (DMD)

In brief

The primary purpose of this study is to evaluate the safety, tolerability, and dystrophin protein levels in muscle tissue following multiple intravenous (IV) doses of DYNE-251 in participants with Duchenne muscular dystrophy (DMD) amenable to exon 51 skipping. The study consists of 3 periods: a multiple-ascending dose (MAD) / placebo-controlled period (24 weeks), an open-label period (24 weeks) and a long-term extension (LTE) period (192 weeks).

Key facts

Study ID

NCT05524883

Run by

Dyne Therapeutics

People needed

86

Starts

2022-08-12

Expected to finish

2029-11-01

Last updated by the study team

2025-08-13

Who can join

Age: 4 and older, up to 16. Sex: male. Healthy volunteers: not accepted.

You may qualify if…

• Age 4 to 16 years inclusive, at the time of informed consent/assent.
• Male with a confirmed diagnosis of DMD and with a mutation in the dystrophin gene characterized by exon deletion amenable to exon 51 skipping.
• Upper extremity muscle group that is amenable to muscle biopsy.
• Brooke Upper Extremity Scale score of 1 or 2.
• Ambulatory or non-ambulatory. A non-ambulatory participant must have been non-ambulatory for <2 years before enrollment.
• Receiving a stable dosage of glucocorticoids for at least 12 weeks prior to the start of study drug administration, with the expectation of maintaining a stable dose during the Placebo-Controlled and Open-Label Periods of the study (unless dose adjustment is required by weight change).
• Left ventricular ejection fraction of ≥50% by echocardiogram or ≥55% by cardiac magnetic resonance imaging (MRI).

You may not qualify if…

• Uncontrolled clinical symptoms and signs of congestive heart failure (CHF).
• Any change in prophylaxis/treatment for CHF within 3 months prior to the start of study treatment.
• History of major surgical procedure within 12 weeks prior to the start of study drug administration or an expectation of a major surgical procedure during the study.
• Requirement of daytime ventilator assistance.
• Percent predicted FVC <40 % (applies only for participants who are age ≥7 years).
• Receipt of eteplirsen, or alternative exon-skipping/dystrophin-modifying therapy, within 12 weeks of randomization.
• Receipt of non-exon skipping investigational drug within 4 months before the start of study drug administration.
• Receipt of gene therapy at any time.
• Other inclusion and exclusion criteria may apply.

Where it is running

• University of California San Diego — La Jolla, California, United States
• UCLA University California of Los Angeles — Los Angeles, California, United States
• Children's Hospital Colorado — Aurora, Colorado, United States
• Rare Disease Research, LLC — Atlanta, Georgia, United States
• UMass Memorial Medical Center — Worcester, Massachusetts, United States
• Nationwide Children's Hospital — Columbus, Ohio, United States
• Shriners Hospitals for Children Portland — Portland, Oregon, United States
• Children's Hospital of Philadelphia — Philadelphia, Pennsylvania, United States
• UPMC Children's Hospital of Pittsburgh — Pittsburgh, Pennsylvania, United States
• University of Utah - PPDS — Salt Lake City, Utah, United States
• Virginia Commonwealth University — Richmond, Virginia, United States
• Children's Hospital at Westmead — Westmead, New South Wales, Australia
• Murdoch Children's Research Institute — Parkville, Victoria, Australia
• UZ Gent — Ghent, Belgium
• UZ Leuven — Leuven, Belgium
• CHR Citadelle — Liège, Belgium
• London Health Sciences Centre — London, Ontario, Canada
• Children's Hospital of Eastern Ontario — Ottawa, Ontario, Canada
• CHI [Children's Health Ireland] at Temple Street Children's University Hospital — Dublin, Ireland
• Fondazione Policlinico Universitario A Gemelli — Rome, Lazio, Italy
• Fondazione Serena Onlus - Centro Clinico NeMO — Milan, Lombardy, Italy
• Ospedale San Raffaele S.r.l. - PPDS — Milan, Lombardy, Italy
• Samsung Medical Center — Seoul, Teugbyeolsi, South Korea
• Hospital Universitario Vall d'Hebron - PPDS — Barcelona, Spain
• Hospital Sant Joan de Déu Universidad de Barcelona — Barcelona, Spain

Full record on ClinicalTrials.gov

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