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

NCT ID: NCT05693142

Last Updated: 2025-11-10

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE2/PHASE3

Total Enrollment

65 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-01-04

Study Completion Date

2028-08-31

Brief Summary

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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.

For additional information on how to participate (or be considered for the study), please follow this link: https://mytomorro.ws/affinity-ct-gov

Detailed Description

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Duchenne muscular dystrophy (Duchenne) is a rare genetic disorder, caused by mutations in the gene responsible for making dystrophin, a protein of central importance for muscle cell structure and function. The absence of functional dystrophin protein in individuals with Duchenne results in cell damage during muscle contraction leading to cell death, inflammation, and fibrosis in muscle tissues, and ultimately progressive muscle weakness. RGX-202 is designed to use the AAV8 vector to deliver a transgene to muscle cells that encodes a novel microdystrophin that includes the functional elements of naturally occurring dystrophin including the C-Terminal (CT) domain.

This is a multicenter, phase I/II/III, open-label study to evaluate the safety, tolerability, pharmacodynamics (microdystrophin protein levels), pharmacokinetic, and clinical efficacy of RGX-202 when administered IV as one-time dose to ambulant male participants with Duchenne. A comprehensive, short-term, prophylactic immunosuppression regimen will be administered during treatment to mitigate a potential immune response. This study is being conducted in three sequential parts: a phase I/II study (Part 1), a phase 3 pivotal study (Part 2) and a confirmatory study (Part 3). Part 1 will study a one-time dose of RGX-202 (1x10\^14 or 2x10\^14 GC/kg) in up to 15 participants with Duchenne. In part 1, the primary objective is to evaluate the safety and tolerability of RGX-202 through 52 weeks. Part 2 (Pivotal Expansion) will study a single dose of RGX-202 (2x10\^14 GC/kg) in approximately 30 participants. After the last Part 2 participant is dosed, enrollment into the confirmatory study (Part 3) will be initiated. The target enrollment for the confirmatory study (Part 3) is approximately 30 participants. Participants will be assessed at various time points for 104 weeks after receiving RGX-202. All participants will be given the opportunity to enroll in a separate long-term follow-study in accordance with the US federal government guidelines for the safety follow-up of patients receiving gene therapy.

Conditions

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Duchenne Muscular Dystrophy

Keywords

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Gene therapy DMD Duchenne Muscular Dystrophy Duchenne

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Dose Evaluation
Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Part 1: Cohort 1 and 1b: RGX-202 Dose 1

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

Group Type EXPERIMENTAL

RGX-202

Intervention Type GENETIC

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

Part 1: Cohort 2, 2c;, and Part 2; and Part 3: RGX-202 Dose 2

A single IV infusion of RGX-202 at a dose of 2x10\^14 GC/kg body weight

Group Type EXPERIMENTAL

RGX-202

Intervention Type GENETIC

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

Interventions

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RGX-202

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

Intervention Type GENETIC

Eligibility Criteria

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Inclusion Criteria

* 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.
* Participant and parent(s)/legal guardian(s) are willing and able to comply with scheduled visits, study intervention administration plan, and study procedures.
* Is a male at least 1 year of age and ≥ 10 kg at the time of screening.
* Participants 1 to \<4 years of age must meet the following criteria:

* is able to walk 10 meters independently without assistive devices.
* must be consistently on or off a stable dose of systemic glucocorticoids according to the standard of care for at least 12 weeks.
* Participants 4 years and older must meet the following criteria:

* are able to walk 100 meters independently without assistive devices.
* have been on a stable dose of systemic glucocorticoids according to the standard of care for at least 12 weeks.
* have a NSAA total score ≥16.

Exclusion Criteria

* 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 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 detectable AAV8 total binding antibodies in serum.
* 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.
Minimum Eligible Age

1 Year

Eligible Sex

MALE

Accepts Healthy Volunteers

No

Sponsors

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REGENXBIO Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Arkansas Children's Hospital

Little Rock, Arkansas, United States

Site Status RECRUITING

Stanford School of Medicine /Division of Neuromuscular Medicine

Palo Alto, California, United States

Site Status RECRUITING

Children's Hospital Colorado

Aurora, Colorado, United States

Site Status RECRUITING

Rare Disease Research

Atlanta, Georgia, United States

Site Status RECRUITING

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

Chicago, Illinois, United States

Site Status RECRUITING

University of Iowa

Iowa City, Iowa, United States

Site Status RECRUITING

University of Massachusetts Chan Medical School

Worcester, Massachusetts, United States

Site Status RECRUITING

Cincinnati Children's

Cincinnati, Ohio, United States

Site Status NOT_YET_RECRUITING

Oregon Health & Science University

Portland, Oregon, United States

Site Status RECRUITING

The University of Texas Southwestern Medical Center

Dallas, Texas, United States

Site Status RECRUITING

Children's Hospital of the King's Daughters

Norfolk, Virginia, United States

Site Status RECRUITING

Children's Hospital of Richmond at Virginia Commonwealth University

Richmond, Virginia, United States

Site Status RECRUITING

Alberta Children's Hospital

Calgary, Alberta, Canada

Site Status NOT_YET_RECRUITING

BC Children's Hospital

Vancouver, British Columbia, Canada

Site Status RECRUITING

Children's Hospital London Health Science Centre

London, Ontario, Canada

Site Status RECRUITING

Children's Hospital of Eastern Ontario

Ottawa, Ontario, Canada

Site Status RECRUITING

Countries

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United States Canada

Central Contacts

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Patient Advocacy

Role: CONTACT

Phone: (833) 711-0349

Email: [email protected]

Facility Contacts

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Amber Evans

Role: primary

Role: primary

Michele Yang

Role: primary

Hannah Kleiner

Role: backup

Lily Goggans

Role: primary

Maureen Ikpeoha

Role: backup

Nicole Geanous

Role: primary

Laura Knosp

Role: primary

Tyler Mola

Role: primary

Angela Edmondson

Role: primary

Beata Dyar

Role: primary

Elaine Most

Role: primary

Erika Paradiso

Role: primary

Falgun Patel

Role: primary

Israt Yasmeen, MBT

Role: primary

Nela Martic

Role: primary

Rhiannon Hicks

Role: primary

Laura Thompson

Role: primary

Related Links

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https://mytomorrows.com/trials/affinity-duchenne/en-us/?utm_source=ct-gov&utm_medium=referral

For additional information on how to participate (or be considered for the study) please follow this link.

Other Identifiers

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RGX-202-1101

Identifier Type: -

Identifier Source: org_study_id