June 24, 2026 —
REGENXBIO plans to file a Biologics License Application in the third quarter of 2026 for RGX-202, its investigational AAV8 gene therapy for Duchenne muscular dystrophy, under the FDA’s accelerated approval pathway.
RGX-202 is designed to deliver a microdystrophin gene using an AAV8 vector, with the goal of partially restoring dystrophin function in muscle. Duchenne muscular dystrophy is a severe, progressive genetic muscle disease that leads to loss of ambulation, respiratory complications, cardiomyopathy, and early mortality.
The planned filing follows data from the Phase 3 portion of REGENXBIO’s AFFINITY DUCHENNE trial. In May, the company reported that the study met its primary endpoint, with 93% of 30 treated boys achieving at least 10% microdystrophin expression at week 12. REGENXBIO said microdystrophin expression was associated with statistically significant functional improvement, which the company believes supports an accelerated approval application.
Safety remains an important focus for the program. Two patients experienced serious adverse events, including one case of liver injury and one case of myocarditis. REGENXBIO said both events were managed and resolved within weeks. The company has described RGX-202 as having a differentiated safety profile, while acknowledging ongoing discussions with regulators around the appropriate path forward.
The planned RGX-202 filing comes amid a broader shift in FDA engagement with rare disease gene therapy programs. REGENXBIO recently announced renewed alignment with the FDA on NAVSUNLI™, its investigational one-time gene therapy for Hunter syndrome, after the agency confirmed that existing data could support accelerated approval review without requiring additional studies or a new untreated control arm.
REGENXBIO is now seeking to apply similar regulatory momentum to its Duchenne program. The company has noted that the RGX-202 pivotal dataset aligns with established accelerated approval considerations, including the magnitude of functional improvement, the relationship between biomarker expression and functional outcomes, and the overall safety profile.
If the BLA is accepted and reviewed successfully, REGENXBIO believes RGX-202 could receive a potential approval decision in the second half of 2027. The company is also preparing for potential commercialization through its in-house manufacturing facility in Maryland, where pre-commercial production began in 2025.
RGX-202 is part of an increasingly competitive Duchenne gene therapy landscape, where developers are working to improve the balance between dystrophin expression, clinical benefit, durability, and safety. While microdystrophin-based AAV therapies remain under scrutiny, REGENXBIO’s accelerated approval strategy underscores the continuing urgency to develop disease-modifying treatments for boys living with Duchenne muscular dystrophy.
