Trial win in hand, Regenxbio to pursue accelerated approval for Duchenne gene therapy

Regenxbio announced positive topline and interim functional phase 3 data for RGX-202, its potential best-in-class gene therapy for Duchenne muscular dystrophy, teeing up an FDA submission.

The pivotal phase 3 portion of the phase 1/2/3 AFFINITY DUCHENNE trial, launched in November 2024, met its primary endpoint with high statistical significance, with 93% of participants reaching at least 10% microdystrophin expression at week 12 (n=30). Additionally, RGX-202 demonstrated statistically significant correlation between microdystrophin expression and interim functional improvement.

"RGX-202 is the first gene therapy in development for Duchenne to demonstrate strong, statistically significant correlation between microdystrophin expression and functional improvement, a landmark distinction in the field," said Steve Pakola, MD, Regenxbio chief medical officer.

In addition, according to the company, the therapy was well tolerated and demonstrated a favorable safety profile as of last data cut. A proactive, short-course immune suppression regimen in combination with a differentiated construct and product purity levels of more than 80% full capsids may contribute to a favorable safety profile for RGX-202.

RGX-202 is designed to support the delivery and targeted expression of genes throughout skeletal and heart muscle using the proprietary NAV AAV8 vector and a well-characterized muscle-specific promoter (Spc5-12).

Regenxbio says it plans to pursue accelerated approval for RGX-202 and is preparing for a potential commercial launch in 2027. The company is also finalizing the trial design for an ex-U.S. study to support global regulatory submissions.