A Gene Transfer Therapy Study to Evaluate the Safety and Efficacy of Delandistrogene Moxeparvovec (SRP-9001) Following Imlifidase Infusion in Participants With Duchenne Muscular Dystrophy (DMD) Determined to Have Pre-existing Antibodies to Recombinant Adeno-Associated Virus Serotype (rAAVrh74)

NCT06241950 | Terminated Phase 1 DMC FDA Drug

• 2 other identifiers: SRP-9001-1042022-003407-15
• Study Type: interventional
• Target: 5
• Locations: 1 country
• Sites: 1

Brief Summary

This is a gene transfer therapy study evaluating the safety of delandistrogene moxeparvovec and delandistrogene moxeparvovec dystrophin expression in association with imlifidase, in participants with DMD with pre-existing antibodies to rAAVrh74 over a period of 104 weeks.

Conditions

Duchenne Muscular Dystrophy

Keywords

Gene-Delivery; DMD; Ambulatory; Pediatric; Duchenne; Pre-existing antibodies; rAAVrh74 Antibody; Seropositive; Seropositivity; Titer

Outcome Measures

Primary Outcomes (4)

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

  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 (5)

• Maximum Observed Plasma Concentration (Cmax) of Imlifidase

  Up to Day 7

• Total IgG in Serum After Imlifidase Administration

  Up to Week 12

• rAAVrh74 Antibody Titers After Imlifidase Administration

  Up to Hour 120

• Concentration of Vector Genome Copies Using Polymerase Chain Reaction in Serum, After Delandistrogene Moxeparvovec Administration

  Up to Day 7

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

  Up to Week 104

Study Arms (1)

Delandistrogene Moxeparvovec after Imlifidase Infusion

EXPERIMENTAL

Participants may receive 1 or 2 doses of imlifidase, depending on rAAVrh74 antibody titer results. Then, based on their rAAVrh74 antibody titer, eligible participants may receive 1 dose of delandistrogene moxeparvovec infusion.

Genetic: delandistrogene moxeparvovec; Biological: imlifidase

Interventions

delandistrogene moxeparvovec GENETIC

Single IV infusion of delandistrogene moxeparvovec

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

Delandistrogene Moxeparvovec after Imlifidase Infusion

imlifidase BIOLOGICAL

IV infusion of Imlifidase

Also known as: Idefirix

Delandistrogene Moxeparvovec after Imlifidase Infusion

Eligibility Criteria

• Age: 4 Years - 9 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 confirmatory genetic testing.
• Ability to cooperate with motor assessment testing.
• Has elevated rAAVrh74 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.
• 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:

• Previous treatment with imlifidase.
• 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 receiving the study drugs 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
• Hansa Biopharma AB: collaborator

Study Sites (1)

Hospital Sant Joan de Déu

Barcelona, 08950, Spain

Location

MeSH Terms

Conditions

Muscular Dystrophy, Duchenne

Interventions

Mac-1-like protein, Streptococcus

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

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: January 26, 2024
• First Posted: February 5, 2024
• Study Start: January 29, 2024
• Primary Completion: October 10, 2025
• Study Completion: October 10, 2025
• Last Updated: November 20, 2025

Record last verified: 2025-11

Locations

ES (1)