This Week’s CGT News: Duchenne Gene Therapy Hits Pivotal Mark

REGENXBIO reports phase III AAV data in Duchenne; plus: adenoviral immunotherapy, preconditioning-free CAR-T, in vivo immune programming, and DNA-guided CRISPR

May 25, 2026
7 min

The Medicine Maker

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

Endpoint	Results
Microdystrophin Expression at Week 12	93% of evaluable participants achieved at least 10% expression
Sustained Editing Duration	At least 3 months post-dose
Serious Adverse Events	None reported

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.