Duchenne Muscular Dystrophy (DMD)Phase 3FORZETTONCT07608432
Efficacy, Safety, and Tolerability of Zeleciment Rostudirsen (DYNE-251) Administered Intravenously Every 4 Weeks in Ambulatory Participants With Duchenne Muscular Dystrophy (FORZETTO)
A Phase 3 study testing Zeleciment Rostudirsen (DYNE-251) in people with Duchenne Muscular Dystrophy (DMD) and Muscular Dystrophy, Duchenne, run by Dyne Therapeutics at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 4 to 18 years, men only
- Conditions the study is for
- Duchenne Muscular Dystrophy (DMD), Muscular Dystrophy, Duchenne, Muscular Dystrophy (DMD)
- What is being tested?
- Zeleciment Rostudirsen (DYNE-251)
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 90 participants
- Where
- 1 siteUnited States
- Study dates
- Jun 2026to Oct 2032
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 18 years
- Men only
- No healthy volunteers
- Child, Adult
Who may be able to join
- 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)
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Rare Disease Research, LLC
Hillsborough, North Carolina, 27278
Hannah Nation, 984-314-2252, hannah.nation@rarediseaseresearch.com
About this study
Official title: A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Investigate the Efficacy, Safety, and Tolerability of DYNE-251 Administered Intravenously in Ambulatory Male Participants 4 to 18 Years of Age With Duchenne Muscular Dystrophy Amenable to Exon-51 Skipping
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.
Read the detailed description
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).
- Conditions
- Duchenne Muscular Dystrophy (DMD), Muscular Dystrophy, Duchenne, Muscular Dystrophy (DMD), DMD, Muscular Dystrophies, Muscular Dystrophy in Children
- Being tested
- Zeleciment Rostudirsen (DYNE-251), Placebo
- Keywords
- Ambulatory, DMD, Duchenne Muscular Dystrophy, Duchenne, Dyne, Dyne Therapeutics, DYNE-251, Dystrophy, Exon Skipping, Exon 51, FORZETTO, Pediatric, PMO, Muscle Function, Muscular Dystropy, Duchenne, Rise From Floor, RFF, RFF Velocity, Rostudirsen, Time to rise
- Medical subject headings
- Muscular Dystrophy, Duchenne, Muscular Dystrophies, Myotonic Dystrophy, Genetic Diseases, Inborn, Genetic Diseases, X-Linked, Congenital, Hereditary, and Neonatal Diseases and Abnormalities, Neuromuscular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Zeleciment Rostudirsen (DYNE-251)Drug
Administered by IV infusion
PlaceboDrug
Administered by IV infusion
| Study group | Role | What they receive |
|---|---|---|
| Placebo-Controlled Period: Zeleciment Rostudirsen (DYNE-251) | Experimental | Participants will be randomized to receive zeleciment rostudirsen, once every 4 weeks (Q4W) for up to 72 weeks. Receives: Drug: Zeleciment Rostudirsen (DYNE-251) |
| Placebo-Controlled Period: Placebo | Placebo comparator | Participants will be randomized to receive placebo, Q4W for up to 72 weeks. Receives: Drug: Placebo |
| Open-Label Long-Term Extension Period: Zeleciment Rostudirsen (DYNE-251) | Experimental | All participants who complete the Placebo-Controlled Period of the study will receive zeleciment rostudirsen administered Q4W for up to 96 weeks. Receives: Drug: Zeleciment Rostudirsen (DYNE-251) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rise From Floor (RFF) velocity
Measured: Baseline, Week 73
Secondary outcomes (21)
RFF (Rise From Floor) velocity
Measured: Baseline, up to Week 169
Stride Velocity 95th Percentile (SV95C)
Measured: Baseline, Week 73, up to Week 169
North Star Ambulatory Assessment (NSAA) Total Score
Measured: Baseline, Week 73, up to Week 169
10-Meter Walk/Run (10MWR) Velocity
Measured: Baseline, Week 73, up to Week 169
4-Stair Climb (4SC) velocity
Measured: Baseline, Week 73, up to Week 169
Functional Composite score
Measured: Baseline, Week 73, up to Week 169
Forced Vital Capacity (FVC)
Measured: Baseline, Week 73, up to Week 169
Patient Global Impression of Severity (PGI-S)
Measured: Baseline, Week 73, up to Week 169
Outcome of Patient Global Impression of Change (PGI-C)
Measured: Week 73, up to Week 169
Blood Creatine Kinase (CK) levels
Measured: Baseline, Week 73, up to Week 169
Incidence of participants With Treatment-Emergent Adverse Events (TEAEs)
Measured: Through study completion, up to Week 173
Maximum Observed Plasma Drug Concentration of DYNE-251 (Cmax)
Measured: Through study completion, up to Week 169
Time to Maximum Observed Plasma Drug Concentration of DYNE-251 (tmax)
Measured: Through study completion, up to Week 169
Area Under the Plasma Drug Concentration-Time Curve From Time 0 to the Last Quantifiable Concentration of DYNE-251 in Plasma (AUC-tlast)
Measured: Through study completion, up to Week 169
Area Under the Plasma Drug Concentration Versus Time Curve From Time 0 (Dosing) Extrapolated to Time Infinity of DYNE-251 (AUC∞)
Measured: Through study completion, up to Week 169
Apparent Terminal Phase Elimination Rate Constant of DYNE-251 in Plasma (λz)
Measured: Through study completion, up to Week 169
Apparent Terminal Elimination Half-Life of DYNE-251 in Plasma (t½)
Measured: Through study completion, up to Week 169
Total Body Clearance (CL) of DYNE-251
Measured: Through study completion, up to Week 169
Volume of Distribution at the Terminal Phase of DYNE-251 in Plasma (Vz)
Measured: Through study completion, up to Week 169
Volume of Distribution at Steady State of DYNE-251 in Plasma (Vss)
Measured: Through study completion, up to Week 169
Incidence of Participants With Antidrug Antibodies (ADAs)
Measured: Through study completion, up to Week 169
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 May 2026
- Study startJun 2026 (estimated)
- Primary completionDec 2030 (estimated)
- Study completionOct 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Duchenne Muscular Dystrophy (DMD)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 90 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Dyne Therapeutics
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07608432
- Sponsor's protocol ID
- DYNE251-DMD-301
- Other IDs
- 2025-524096-23-00, 2025
- Acronym
- FORZETTO
- Status last verified
- May 2026
- First submitted
- 20 May 2026
- Last updated
- 27 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No