Efficacy, Safety, and Tolerability of Zeleciment Rostudirsen (DYNE-251) Administered Intravenously Every 4 Weeks in Ambulatory Participants With Duchenne Muscular Dystrophy (FORZETTO)

Phase 3RecruitingNCT07608432

Dyne Therapeutics90 enrolled

Overview

The purpose of the study is to assess the efficacy, safety, and tolerability of zeleciment rostudirsen (DYNE-251) administered intravenously (IV) every 4 weeks to ambulatory Duchenne muscular dystrophy (DMD) participants, 4 to 18 years of age, with dystrophin mutations amenable to exon 51 skipping.

The study consists of three periods: a Screening period (up to 6 weeks), a Placebo-Controlled Period (72 weeks) and an open-label Long-Term Extension Period (96 weeks).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Duchenne Muscular Dystrophy (DMD)Muscular Dystrophy, Duchenne Muscular Dystrophy (DMD)DMD Muscular Dystrophies

Eligibility

Sex: MALEMin age: 4 YearsMax age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Ambulatory male with confirmed diagnosis of DMD and with a mutation in the dystrophin gene characterized by exon deletion amenable to exon 51 skipping . * Rise From Floor (RFF) time must be \< 10 seconds for both screening assessments . * Receiving a stable daily or weekend dosage of glucocorticoids for at least 24 weeks prior to randomization with the expectation of maintaining a stable dose during the Placebo-Controlled Period of the study (unless dose adjustment is required by weight change) Exclusion Criteria: * Receipt of ongoing immunosuppressive therapy (other than glucocorticoids) within 12 weeks prior to randomization * Use of any pharmacologic treatment (other than glucocorticoids) that may have an effect on muscle strength or function within 12 weeks prior to randomization * Any change in prophylaxis/treatment for congestive heart failure (CHF) within 12 weeks prior to randomization * Receipt of eteplirsen within 1 week prior to randomization * Receipt of alternative exon-skipping or dystrophin-modifying therapy or zeleciment rostudirsen within 24 weeks prior to randomization * Receipt of givinostat within 12 weeks prior to randomization * Receipt of gene therapy at any time Note: Other inclusion or exclusion criteria may apply

Outcomes

Primary Outcomes

Rise From Floor (RFF) velocity

Time frame: Baseline, Week 73

Secondary Outcomes

RFF (Rise From Floor) velocity

Time frame: Baseline, up to Week 169

Stride Velocity 95th Percentile (SV95C)

Time frame: Baseline, Week 73, up to Week 169

North Star Ambulatory Assessment (NSAA) Total Score

Time frame: Baseline, Week 73, up to Week 169

10-Meter Walk/Run (10MWR) Velocity

Time frame: Baseline, Week 73, up to Week 169

4-Stair Climb (4SC) velocity

Time frame: Baseline, Week 73, up to Week 169

Functional Composite score

Time frame: Baseline, Week 73, up to Week 169

Forced Vital Capacity (FVC)

Time frame: Baseline, Week 73, up to Week 169

Patient Global Impression of Severity (PGI-S)

Time frame: Baseline, Week 73, up to Week 169

Outcome of Patient Global Impression of Change (PGI-C)

Time frame: Week 73, up to Week 169

Blood Creatine Kinase (CK) levels

Time frame: Baseline, Week 73, up to Week 169

Incidence of participants With Treatment-Emergent Adverse Events (TEAEs)

Time frame: Through study completion, up to Week 173

Maximum Observed Plasma Drug Concentration of DYNE-251 (Cmax)