AFFINITY DUCHENNE: RGX-202 Gene Therapy in Participants With Duchenne Muscular Dystrophy (DMD)

NCT05693142 | Active Not Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: RGX-202-1101
• Study Type: interventional
• Target: 65
• Locations: 2 countries
• Sites: 23

Brief Summary

RGX-202 is a gene therapy designed to deliver a transgene for a novel microdystrophin that includes functional elements of naturally-occurring dystrophin including the C-Terminal (CT) domain. This is a multicenter, open-label dose evaluation clinical study to assess the safety, tolerability, and clinical efficacy of a one-time intravenous (IV) dose of RGX-202 in participants with Duchenne.

Conditions

Duchenne Muscular Dystrophy

Keywords

Gene therapy; DMD; Duchenne Muscular Dystrophy; Duchenne

Outcome Measures

Primary Outcomes (2)

• Part 1 Safety measured by incidence of Adverse Events and Serious Adverse Events

  Evaluate incidences of AEs and SAEs

  52 weeks

• Part 2 and 3 Pharmacodynamic

  Proportion of participants whose RGX-202 microdystrophin protein expression determined in their muscle biopsy is ≥ 10% relative to dystrophin level in non-DMD participants

  12 weeks

Secondary Outcomes (14)

• Time to Stand (TTSTAND)

  52 Weeks (Part 1); 52 and 104 Weeks (Part 2 &3)

• Time to Walk/Run 10 meters (TTWR)

  52 Weeks (Part 1) and 104 Weeks (Part 2 &3)

• Time to Climb 4 Stairs (TTCLIMB)

  52 Weeks (Part 1); 52 and 104 Weeks (Part 2 &3)

• North Star Ambulatory Assessment (NSAA)

  52 Weeks (Part 1) and; 52 and 104 Weeks (Part 2 &3)

• Peabody Developmental Motor Scale, Third Edition (PDMS-3); Body Control Subtest

  52 Weeks (Part 1); 52 and 104 Weeks (Part 2 &3)

Study Arms (2)

Part 1: Cohort 1 and 1b (enrollment complete): RGX-202 Dose 1

EXPERIMENTAL

A single IV infusion of RGX-202 at a dose of 1×10\^14 GC/kg body weight

Genetic: RGX-202

Part 1: Cohort 2, 2c;, and Part 2; and Part 3 (enrollment complete for all): RGX-202 Dose 2

EXPERIMENTAL

A single IV infusion of RGX-202 at a dose of 2x10\^14 GC/kg body weight (or a fixed dose of 1.00×10\^16 GC \[150 mL\] for participants weighing \> 50 kg)

Genetic: RGX-202

Interventions

RGX-202 GENETIC

RGX-202 is a recombinant AAV8 containing a transgene encoding a novel microdystrophin

Part 1: Cohort 1 and 1b (enrollment complete): RGX-202 Dose 1; Part 1: Cohort 2, 2c;, and Part 2; and Part 3 (enrollment complete for all): RGX-202 Dose 2

Eligibility Criteria

• Age: 1 Year+
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• The participant's legal guardian(s) is (are) willing and able to provide written, signed informed consent prior to any study-related procedures; and, where applicable, the minor participant has provided written or verbal assent according to local requirements.
• Is a male at least 4 years of age and less than 12 years of age at consent or 1 to \<4 years of age at the time of dosing and ≥ 10 kg at the time of screening.
• Must meet any of the following criteria:
• DMD gene mutation in exons 18 and above, and a clinical picture consistent with typical DMD with the exception of a participant (Cohort 1b) with DMD gene mutation in exons 12-17.
• Participant is able to walk 100 meters independently without assistive devices. Cohort 2c participant must be able to walk 10 meters independently without assistive devices. Cohort 1b participant must be able to walk with or without assistive devices.
• Participant is able to complete the TTSTAND per protocol-specific criteria.
• Participant has been on a stable dose of systemic glucocorticoids according to the standard of care for at least 12 weeks. Cohort 2c participants must be consistently on or off a stable dose of systemic glucocorticoids according to the standard of care for at least 12 weeks.
• Clinical laboratory test results, including hepatic and renal function, are within the normal range during screening, or if abnormal, are not clinically significant, in the opinion of the investigator.
• Documentation is provided at screening visit for participant's adherence to the local country's vaccination schedule. The parent(s) or legal guardian(s) must be willing to have their child receive a meningococcal vaccine, if not already vaccinated.
• Participant and parent(s)/legal guardian(s) are willing and able to comply with scheduled visits, study intervention administration plan, and study procedures.
• The participant's legal guardian(s) is (are) willing and able to provide written, signed informed consent prior to any study-related procedures; and, where applicable, the minor participant has provided written or verbal assent according to local requirements.
• DMD gene mutation with any mutation except for those with deletions or point mutations in exons 8, 9 and/or 10.
• Participant is able to complete the TTSTAND per protocol-specific criteria.
• Clinical laboratory test results, including hepatic and renal function, are within the normal range during screening, or if abnormal, are not clinically significant, in the opinion of the investigator.
• Documentation is provided at screening visit for participant's adherence to the local country's vaccination schedule. The parent(s) or legal guardian(s) must be willing to have their child receive a meningococcal vaccine, if not already vaccinated.

You may not qualify if:

• Participant has any condition that would contraindicate treatment with immunosuppression.
• Participant has received ataluren (a protein restoration therapy) or an exon-skipping therapy for the treatment of DMD within 6 months of study entry or is unable to refrain from taking ataluren or exon-skipping therapy for a duration of 5 years from the time of RGX-202 administration.
• Participant has received any investigational or commercial gene therapy product over his lifetime.
• Participant is currently taking any other investigational intervention (other than corticosteroids) or has taken any other investigational intervention (other than corticosteroids) within 3 months prior to the scheduled Day 1 intervention. If your corticosteroid is vamorolone, the participant will be asked to temporarily convert his daily dosing to prednisolone/prednisone during a short period of time around RGX-202 administration. He will be allowed to revert back to his baseline vamorolone regimen at the original per kilogram dose at which he entered the study and should remain on this for 24 months unless the investigator determines that this is not clinically indicated or possible.
• Participant has impaired cardiac function defined as a left ventricular ejection fraction of \< 55% on screening cardiac assessments (echocardiogram or MRI).
• Participant is not a good candidate for the study, in the opinion of the investigator.
• Participant has any condition that would contraindicate treatment with immunosuppression.
• Participant has received givinostat within 3 months of study entry or has received ataluren (a protein restoration therapy) or an exon-skipping therapy for the treatment of DMD within 6 months of study entry or is unable to refrain from taking ataluren or exon-skipping therapy for a duration of 5 years from the time of RGX-202 administration.
• Participant has received any investigational or commercial gene therapy product over his lifetime.
• Participant is currently taking any other investigational intervention (other than corticosteroids) or has taken any other investigational intervention (other than corticosteroids) within 3 months prior to the scheduled Day 1 intervention. If the corticosteroid is vamorolone, the participant will be asked to temporarily convert his daily dosing to prednisolone/prednisone during a short period of time around RGX-202 administration. He will be allowed to revert back to his baseline vamorolone regimen at the original per kilogram dose at which he entered the study and should remain on this for 24 months unless the investigator determines that this is not clinically indicated or possible.
• Participant has detectable titer of \>1:50 for AAV8 total binding antibodies in serum at screening.
• Participant has impaired cardiac function defined as a left ventricular ejection fraction of \< 55% on screening cardiac assessments echocardiogram or MRI).
• Participant is not a good candidate for the study, in the opinion of the investigator.

Sponsors & Collaborators

• REGENXBIO Inc.: lead

Study Sites (23)

Arkansas Children's Hospital

Little Rock, Arkansas, 72202, United States

Location

Children's Hospital of Orange County

Orange, California, 92868, United States

Location

Stanford School of Medicine /Division of Neuromuscular Medicine

Palo Alto, California, 94304, United States

Location

Children's Hospital Colorado

Aurora, Colorado, 80045, United States

Location

University of Florida

Gainesville, Florida, 32610, United States

Location

Rare Disease Research

Atlanta, Georgia, 30329, United States

Location

Ann & Robert H. Lurie Children's Hospital of Chicago

Chicago, Illinois, 60611, United States

Location

University of Iowa

Iowa City, Iowa, 52242, United States

Location

University of Kansas Medical Center

Kansas City, Kansas, 60160, United States

Location

University of Massachusetts Chan Medical School

Worcester, Massachusetts, 01608, United States

Location

Helen DeVos Children's Hospital

Grand Rapids, Michigan, 49503, United States

Location

Columbia University Medical Center

New York, New York, 10032, United States

Location

Cincinnati Children's

Cincinnati, Ohio, 45229, United States

Location

Nationwide Children's Hospital

Columbus, Ohio, 43205, United States

Location

Oregon Health & Science University

Portland, Oregon, 97239, United States

Location

Monroe Carell Children's Hospital at Vanderbilt

Nashville, Tennessee, 37232, United States

Location

The University of Texas Southwestern Medical Center

Dallas, Texas, 75390, United States

Location

Children's Hospital of the King's Daughters

Norfolk, Virginia, 23510, United States

Location

Children's Hospital of Richmond at Virginia Commonwealth University

Richmond, Virginia, 23298, United States

Location

BC Children's Hospital

Vancouver, British Columbia, V65 3N1, Canada

Location

Children's Hospital London Health Science Centre

London, Ontario, Canada

Location

Children's Hospital of Eastern Ontario

Ottawa, Ontario, K1H 8L1, Canada

Location

The Hospital for Sick Children

Toronto, Ontario, M5G 1X8, Canada

Location

Related Links

• Related Info

MeSH Terms

Conditions

Muscular Dystrophy, Duchenne

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 Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR
• Expanded Access: Yes

Model Details: Dose Evaluation

Study Record Dates

• First Submitted: January 4, 2023
• First Posted: January 20, 2023
• Study Start: January 4, 2023
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): June 1, 2028
• Last Updated: July 21, 2026

Record last verified: 2026-07

Locations

US (19); CA (4)