A Gene Transfer Therapy to Evaluate the Safety and Efficacy of Delandistrogene Moxeparvovec (SRP-9001) Following Therapeutic Plasma Exchange (Plasmapheresis) in Participants With Duchenne Muscular Dystrophy (DMD) and Pre-existing Antibodies to AAVrh74

NCT06597656 | Terminated Phase 1 DMC FDA Drug

• 1 other identifier: SRP-9001-105
• Study Type: interventional
• Target: 3
• Locations: 1 country
• Sites: 3

Brief Summary

This is a gene transfer therapy study evaluating the safety of and delandistrogene moxeparvovec dystrophin protein expression from delandistrogene moxeparvovec following therapeutic plasma exchange (plasmapheresis) in ambulatory male participants with DMD and pre-existing antibodies to AAVrh74 over a period of 59 weeks.

Conditions

Duchenne Muscular Dystrophy

Keywords

Gene-Delivery; DMD; Ambulatory; Pediatric; Duchenne; Seropositive; Pre-existing antibodies; AAVrh74 antibody; Plasmapheresis; Titer; Seropositivity

Outcome Measures

Primary Outcomes (4)

• Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression Adjusted by Muscle Content Biopsied Muscle as Measured by Western Blot

  Baseline, Week 12

• Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression in Biopsied Muscle as Measured by Immunofluorescence (IF) Fiber Intensity

  Baseline, Week 12

• Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression in Biopsied Muscle as Measured by IF Percent Dystrophin-positive Fibers (PDPF)

  Baseline, Week 12

• Mean Concentration of Vector Genome Copies Using Polymerase Chain Reaction in Muscle Tissue Biopsy, After Delandistrogene Moxeparvovec Administration

  Week 12

Secondary Outcomes (2)

• Number of Participants with a Treatment Emergent Adverse Event (TEAE), Adverse Event of Special Interest (AESI), and Serious Adverse Event (SAE)

  Baseline up to End of Study (Up to Week 59)

• Change from Baseline in rAAVrh74 Antibody Titers

  Baseline, Week 1

Study Arms (1)

Delandistrogene Moxeparvovec After Plasmapheresis Procedure

EXPERIMENTAL

Participants will receive a single intravenous (IV) infusion of delandistrogene moxeparvovec on Day 1 after plasmapheresis procedure if AAVrh74 antibodies are sufficiently low.

Genetic: delandistrogene moxeparvovec; Procedure: Plasmapheresis

Interventions

delandistrogene moxeparvovec GENETIC

Single IV infusion of delandistrogene moxeparvovec

Also known as: SRP-9001, delandistrogene moxeparvovec-rokl, ELEVIDYS

Delandistrogene Moxeparvovec After Plasmapheresis Procedure

Plasmapheresis PROCEDURE

Therapeutic plasma exchange procedure

Delandistrogene Moxeparvovec After Plasmapheresis Procedure

Eligibility Criteria

• Age: 4 Years - 8 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Ambulatory per protocol specified criteria.
• Has a definitive diagnosis of DMD prior to Screening based on documentation of clinical findings and prior confirmatory genetic testing.
• Ability to cooperate with motor assessment testing.
• Has elevated AAVrh74 antibody titers per protocol-specified requirements.
• A pathogenic frameshift mutation, nonsense mutation or premature stop codon or pathogenic variant in the DMD gene that is expected to lead to absence of dystrophin protein with exception of a mutation in exon 8 and/or 9.
• Stable daily dose of oral corticosteroids for at least 12 weeks prior to Screening, and the dose is expected to remain constant throughout the study (except for modifications to accommodate changes in weight).

You may not qualify if:

• Has reduced left ventricular ejection fraction on the screening ECHO or clinical signs and/or symptoms of cardiomyopathy.
• Presence of any other clinically significant illness, including cardiac, pulmonary, hepatic, renal, hematologic, immunologic, or behavioral disease, or infection or malignancy or concomitant illness or requirement for chronic drug treatment that in the opinion of the Investigator creates unnecessary risks for gene transfer or a medical condition or extenuating circumstance that, in the opinion of the Investigator, might compromise the participant's ability to comply with the protocol required testing or procedures or compromise the participant's wellbeing, safety, or clinical interpretability.
• Exposure to gene therapy, investigational medication, or other protocol-specified treatment within the protocol specified time limits.
• Abnormality in protocol-specified diagnostic evaluations or laboratory tests. .

Sponsors & Collaborators

• Sarepta Therapeutics, Inc.: lead

Study Sites (3)

University of Florida, College of Medicine

Gainesville, Florida, 32610, United States

Location

Washington University School of Medicine in St. Louis

St Louis, Missouri, 63110, United States

Location

Nationwide Children's Hospital

Columbus, Ohio, 43205, United States

Location

MeSH Terms

Conditions

Muscular Dystrophy, Duchenne

Interventions

Plasmapheresis

Condition Hierarchy (Ancestors)

Muscular Dystrophies; Muscular Disorders, Atrophic; Muscular Diseases; Musculoskeletal Diseases; Neuromuscular Diseases; Nervous System Diseases; Genetic Diseases, X-Linked; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Intervention Hierarchy (Ancestors)

Blood Component Removal; Therapeutics; Sorption Detoxification; Extracorporeal Circulation; Surgical Procedures, Operative

Study Officials

• Medical Director

  Sarepta Therapeutics, Inc.

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 12, 2024
• First Posted: September 19, 2024
• Study Start: September 18, 2024
• Primary Completion: August 5, 2025
• Study Completion: August 5, 2025
• Last Updated: September 4, 2025

Record last verified: 2025-08

Locations

US (3)