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A Study to Compare Safety and Efficacy of High Doses of Eteplirsen in Participants With Duchenne Muscular Dystrophy (DMD) (MIS51ON)

A Randomized, Double-Blind, Dose Finding and Comparison Study of the Safety and Efficacy of High Doses of Eteplirsen, Preceded by an Open-label Dose Escalation, in Patients With Duchenne Muscular Dystrophy With Deletion Mutations Amenable to Exon 51 Skipping

Status
Active, not recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03992430
Acronym
MIS51ON
Enrollment
160
Registered
2019-06-20
Start date
2020-07-13
Completion date
2026-10-31
Last updated
2026-02-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Muscular Dystrophy, Duchenne

Keywords

Duchenne muscular dystrophy, Exon Skipping, Exon 51, North Star Ambulatory Assessment, Ambulatory, DMD, Pediatric, Duchenne, EXONDYS, MIS51ON

Brief summary

Part 1 (dose escalation) will evaluate the safety and tolerability of 2 doses (100 milligrams/kilogram \[mg/kg\] and 200 mg/kg) of eteplirsen in approximately 10 participants with DMD; Part 2 (dose finding and dose comparison) will evaluate the efficacy and safety of the high doses (100 mg/kg and 200 mg/kg) of eteplirsen compared with that of the 30 mg/kg dose of eteplirsen, in approximately 144 participants with genetically confirmed deletion mutations amenable to treatment by skipping exon 51.

Interventions

Solution for intravenous (IV) infusion.

Sponsors

Sarepta Therapeutics, Inc.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

Part 1 is open-label, dose escalation; Part 2 is double-blind, dose finding, and dose comparison

Eligibility

Sex/Gender
MALE
Age
4 Years to 13 Years
Healthy volunteers
No

Inclusion criteria

* Be a male with an established clinical diagnosis of DMD and an out-of-frame deletion mutation of the DMD gene amenable to exon 51 skipping. * Ambulatory participant, able to perform TTRISE in 10 seconds or less at the time of screening visit. * Able to walk independently without assistive devices. * Have intact right and left biceps muscles or an alternative upper arm muscle group. * Have been on a stable dose or dose equivalent of oral corticosteroids for at least 12 weeks prior to randomization and the dose is expected to remain constant (except for modifications to accommodate changes in weight and stress-related needs as per the recently published guidelines throughout the study. * For ages 7 years and older, has stable pulmonary function (forced vital capacity ≥50 percent (%) of predicted and no requirement for nocturnal ventilation). For ages 4 to 6 years, does not require support from ventilator or non-invasive ventilation at time of screening.

Exclusion criteria

* Use of any pharmacologic treatment (other than corticosteroids) within 12 weeks prior to randomization. * Current or previous treatment with any other experimental pharmacologic treatment for DMD or any prior exposure to antisense oligonucleotide, gene therapy or gene editing; except the following: Ezutromid in the last 12 weeks prior to first dose; Drisapersen in the last 36 weeks prior to first dose; Suvodirsen in the last 12 weeks prior to first dose; Vamorolone in the last 12 weeks prior to first dose; Eteplirsen (previous or current use); and Tamoxifen in the last 4 weeks prior to first dose. * Major surgery within 3 months prior to randomization. * Presence of any other significant neuromuscular or genetic disease other than DMD. * Presence of any known impairment of renal function and/or other clinically significant illness. * Has evidence of cardiomyopathy, as defined by left ventricular ejection fraction less than \<50% on the screening echocardiogram or Fridericia's correction formula (QTcF) ≥450 millisecond based on the screening electrocardiograms (ECGs). Other inclusion/

Design outcomes

Primary

MeasureTime frame
Part 1: Incidence of Adverse Events (AEs)Up to Week 148
Part 2: Change From Baseline at Week 144 in the NSAA Total Score (for Final Analysis)Baseline, Week 144
Part 2: Change from Baseline at Week 72 or Week 96 in NSAA Total Score (for Conditional Efficacy Interim Analysis)Baseline, Week 72 or Week 96

Secondary

MeasureTime frame
Part 2: Pharmacokinetic (PK) Plasma Concentration of Eteplirsen0 (predose) to 2 hours postdose up to Week 144
Part 2: Change From Baseline in Time to Rise From the Floor, Time to Complete 10-Meter Walk/Run, and the Timed Stair Ascend TestBaseline, Week 144
Part 2: Change From Baseline in the Total Distance Walked During 6-Minute Walk Test (6MWT)Baseline, Week 144
Part 2: Time to Loss of Ambulation (LOA)Baseline up to Week 144
Part 2: Change from Baseline at Week 144 in Forced Vital Capacity Percent Predicted (FVC%p)Baseline, Week 144
Part 2: Change From Baseline in Skeletal Muscle Dystrophin ExpressionBaseline, Postdose (at Week 24, Week 48, or Week 144)
Part 2: Incidence of Adverse Events (AEs)Baseline up to Week 148

Countries

Colombia, Czechia, Denmark, France, Germany, Greece, Hungary, India, Ireland, Italy, Jordan, Mexico, Netherlands, New Zealand, Norway, Poland, Romania, Serbia, Slovenia, South Korea, Spain, Switzerland, Taiwan, Turkey (Türkiye), United Kingdom, United States

Contacts

STUDY_DIRECTORMedical Director

Sarepta Therapeutics, Inc.

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 28, 2026