Duchenne Muscular DystrophyPhase 1HORIZONNCT06597656
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
A Phase 1 study testing delandistrogene moxeparvovec and Plasmapheresis in people with Duchenne Muscular Dystrophy, run by Sarepta Therapeutics, Inc. at 3 sites in United States.
Trial 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… Read more about this study
- Who is it for?
- Ages 4 to 8 years, men only
- Conditions the study is for
- Duchenne Muscular Dystrophy
- What is being tested?
- delandistrogene moxeparvovec and Plasmapheresis
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 3 participants
- Where
- 3 sitesUnited States
- Study dates
- 18 Sep 2024to 5 Aug 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 8 years
- Men only
- No healthy volunteers
- Child
Who may be able to join
- 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).
Who cannot join
- 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. .
- Note: Other inclusion or exclusion criteria could apply.
Trial locations and contacts
3 sites in 1 country.
United States3 sites
Nationwide Children's Hospital
Columbus, Ohio, 43205
University of Florida, College of Medicine
Gainesville, Florida, 32610
Washington University School of Medicine in St. Louis
St Louis, Missouri, 63110
About this study
Official title: An Open-Label, Systemic Gene Delivery Study to Evaluate the Safety, Tolerability and Expression of Delandistrogene Moxeparvovec Following Plasmapheresis in Subjects With Duchenne Muscular Dystrophy and Pre-existing Antibodies to AAVrh74
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
- Being tested
- delandistrogene moxeparvovec, Plasmapheresis
- Keywords
- Gene-Delivery, DMD, Ambulatory, Pediatric, Duchenne, Seropositive, Pre-existing antibodies, AAVrh74 antibody, Plasmapheresis, Titer, Seropositivity
- Medical subject headings
- Muscular Dystrophy, Duchenne
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
delandistrogene moxeparvovecGenetic
Also called SRP-9001, delandistrogene moxeparvovec-rokl, ELEVIDYS
Single IV infusion of delandistrogene moxeparvovec
PlasmapheresisProcedure or surgery
Therapeutic plasma exchange procedure
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: Genetic: delandistrogene moxeparvovec; Procedure: Plasmapheresis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression Adjusted by Muscle Content Biopsied Muscle as Measured by Western Blot
Measured: Baseline, Week 12
Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression in Biopsied Muscle as Measured by Immunofluorescence (IF) Fiber Intensity
Measured: 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)
Measured: Baseline, Week 12
Mean Concentration of Vector Genome Copies Using Polymerase Chain Reaction in Muscle Tissue Biopsy, After Delandistrogene Moxeparvovec Administration
Measured: 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)
Measured: Baseline up to End of Study (Up to Week 59)
Change from Baseline in rAAVrh74 Antibody Titers
Measured: Baseline, Week 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2024
- Study start18 Sep 2024
- Primary completion5 Aug 2025
- Study completion5 Aug 2025
Why it stopped: Study is being terminated due to a business decision.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Duchenne Muscular DystrophyStudies of the same condition, open and under way.
- More trials run by Sarepta Therapeutics, Inc.The sponsor's other registered studies.
- 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 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 3 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sarepta Therapeutics, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Medical Director, Study director, Sarepta Therapeutics, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06597656
- Sponsor's protocol ID
- SRP-9001-105
- Acronym
- HORIZON
- Status last verified
- Aug 2025
- First submitted
- 12 Sep 2024
- Last updated
- 4 Sep 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Open-Label, Systemic Gene Delivery Study to Evaluate the Safety, Tolerability and Expression of Delandistrogene Moxeparvovec Following Plasmapheresis in Subjects With Duchenne Muscular Dystrophy and Pre-existing Antibodies to AAVrh74
- ClinicalTrials.gov ID
- NCT06597656
- Acronym / sponsor ID
- HORIZON / SRP-9001-105
- Conditions
- Duchenne Muscular Dystrophy
- Keywords
- Gene-Delivery, DMD, Ambulatory, Pediatric, Duchenne, Seropositive, Pre-existing antibodies, AAVrh74 antibody
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Study is being terminated due to a business decision.
- Enrolment
- 3 participants (actual)
- Lead sponsor
- Sarepta Therapeutics, Inc.Industry (pharma, biotech, devices)
- Study start
- 18 Sep 2024 (actual)
- Primary completion
- 5 Aug 2025 (actual)
- Study completion
- 5 Aug 2025 (actual)
- First posted
- 19 Sep 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Delandistrogene Moxeparvovec After Plasmapheresis Procedure | Experimental | Genetic: delandistrogene moxeparvovec, Procedure: PlasmapheresisParticipants will receive a single intravenous (IV) infusion of delandistrogene moxeparvovec on Day 1 after plasmapheresis procedure if AAVrh74 antibodies are sufficiently low. |
Who may qualify
- Ages
- 4 to 8 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (6 listed)
- 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.
Key exclusion criteria (5 listed)
- 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. .
- Note: Other inclusion or exclusion criteria could apply.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| delandistrogene moxeparvovecAlso: SRP-9001, delandistrogene moxeparvovec-rokl, ELEVIDYSSingle IV infusion of delandistrogene moxeparvovec | Genetic | Delandistrogene Moxeparvovec After Plasmapheresis Procedure |
| PlasmapheresisTherapeutic plasma exchange procedure | Procedure or surgery | Delandistrogene Moxeparvovec After Plasmapheresis Procedure |
Primary outcome
Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression Adjusted by Muscle Content Biopsied Muscle as Measured by Western Blot
Time frame: Baseline, Week 12
Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression in Biopsied Muscle as Measured by Immunofluorescence (IF) Fiber Intensity
Time frame: 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)
Time frame: Baseline, Week 12
Mean Concentration of Vector Genome Copies Using Polymerase Chain Reaction in Muscle Tissue Biopsy, After Delandistrogene Moxeparvovec Administration
Time frame: Week 12
2 secondary outcomes
Number of Participants with a Treatment Emergent Adverse Event (TEAE), Adverse Event of Special Interest (AESI), and Serious Adverse Event (SAE)
Time frame: Baseline up to End of Study (Up to Week 59)
Change from Baseline in rAAVrh74 Antibody Titers
Time frame: Baseline, Week 1
Results and safety
The study was stopped early (reason given: Study is being terminated due to a business decision.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Sep 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Medical Director study director
Sarepta Therapeutics, Inc.
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing delandistrogene moxeparvovec and Plasmapheresis in people with Duchenne Muscular Dystrophy, run by Sarepta Therapeutics, Inc. at 3 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 4 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: Study is being terminated due to a business decision.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change From Baseline in Quantity of Delandistrogene Moxeparvovec Dystrophin Expression Adjusted by Muscle Content Biopsied Muscle as Measured by Western Blot (time frame: Baseline, Week 12). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Sep 2025.