Regenxbio announced new interim Phase I/II AFFINITY DUCHENNE trial data for its investigational gene therapy RGX-202 targeting Duchenne muscular dystrophy (DMD) on June 5, 202524.
The trial's new functional, safety, and biomarker data show consistent benefit among patients one year after treatment, especially for those at dose level 224.
All dose level 2 participants exceeded external natural history controls on all functional measures, including the North Star Ambulatory Assessment2.
Biomarker data demonstrated robust and consistent microdystrophin expression and gene transduction across all treated ages, with one 2-year-old participant showing 118.6% expression compared to controls2.
No serious adverse events or adverse events of special interest were observed, indicating a favorable safety profile for RGX-2022.
Analysts noted that while some RGX-202 functional improvements may appear slightly higher than with Sarepta's Elevidys, the efficacy difference is not considered clinically significant due to patient variability and trial design1.
Regenxbio intends to submit a Biologics License Application for RGX-202 under accelerated approval, aiming for mid-202624.
Despite the positive clinical data, Regenxbio's stock dropped significantly following the announcement15.
Sources:
1. https://www.biospace.com/drug-development/regenxbio-fails-to-best-sareptas-elevidys-with-new-data-for-dmd-gene-therapy
2. https://www.prnewswire.com/news-releases/regenxbio-reports-new-positive-functional-data-from-phase-iii-affinity-duchenne-trial-of-rgx-202-302473842.html
4. https://firstwordpharma.com/story/5969473
5. https://www.bioworld.com/articles/720936-regenxbios-duchenne-gene-therapy-data-positive-as-shares-falter