Clinical Report: Duchenne Gene Therapy Hits Pivotal Mark

Overview

REGENXBIO's RGX-202 has shown results in the pivotal phase III AFFINITY DUCHENNE trial, with 93% of participants achieving at least 10% microdystrophin expression at week 12. The therapy demonstrated editing effects for at least three months post-administration without serious adverse events.

Background

Duchenne muscular dystrophy (DMD) is a severe genetic disorder characterized by progressive muscle degeneration. The development of gene therapies, such as RGX-202, represents an advancement in treatment options.

Data Highlights

Key Findings

• 93% of evaluable participants achieved at least 10% microdystrophin expression at week 12.
• Editing effects were sustained for a minimum of three months after the last dose.
• No serious adverse events or clinically meaningful liver test elevations were reported.
• The trial met its primary endpoint successfully.
• RGX-202 is an investigational one-time AAV microdystrophin gene therapy.

Clinical Implications

Ongoing monitoring of safety and efficacy will be essential as the therapy progresses through regulatory pathways.

Conclusion

The findings from the RGX-202 trial represent a milestone in the development of gene therapies for Duchenne muscular dystrophy.

Related Resources & Content

1. REGENXBIO, Regenxbio Inc, 2026 -- Positive Topline Results from Pivotal Phase III AFFINITY DUCHENNE Study of RGX-202
2. FDA, FDA, 2024 -- Expands Approval of Gene Therapy for Patients with Duchenne Muscular Dystrophy
3. AAN Guidelines Subcommittee, PubMed, 2025 -- Delandistrogene Moxeparvovec Gene Therapy in Individuals With Duchenne Muscular Dystrophy: Evidence in Focus
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8. FDA Expands Approval of Gene Therapy for Patients with Duchenne Muscular Dystrophy | FDA
9. Delandistrogene Moxeparvovec Gene Therapy in Individuals With Duchenne Muscular Dystrophy: Evidence in Focus: Report of the AAN Guidelines Subcommittee - PubMed
10. Roche announces new results from EMBARK demonstrating significant sustained benefits of Elevidys in ambulatory individuals with Duchenne muscular dystrophy (DMD)
11. REGENXBIO Announces Positive Topline Results from Pivotal Phase III AFFINITY DUCHENNE® Study of RGX-202 | Regenxbio Inc
12. REGENXBIO Announces Publication of Preclinical Results Demonstrating Functional Benefits of Novel Microdystrophin Construct in RGX-202 Investigational Gene Therapy for Duchenne Muscular Dystrophy | Regenxbio Inc