A Randomized, Double-Blind, Placebo-Controlled, Multiple Ascending Dose Study Assessing Safety, Tolerability, Pharmacodynamics, Efficacy, and Pharmacokinetics of DYNE-251 Administered to Participants With Duchenne Muscular Dystrophy Amenable to Exon 51 Skipping

Trial ID: NCT05524883

Interventional - Phase 1/2 - Active, not recruiting

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 (288 weeks).

Conditions

• Duchenne Muscular Dystrophy (DMD)

Interventions

• DYNE-251
• Placebo

Eligibility

Inclusion criteria

• 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).

Exclusion criteria

• 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.

Sponsor

Dyne Therapeutics

Source: ClinicalTrials.gov

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