REGENXBIO Sees +4.9-Point NSAA Gain, Stable LVEF in Phase I/II Trial
REGENXBIO’s RGX-202 pivotal dose participants (n=7) showed a mean +4.9-point NSAA improvement at one year versus expected trajectory and stable cardiac MRI measures (LVEF 61.7% to 61.6%). No serious adverse events or liver safety issues were observed, with pivotal topline data due Q2 2026.
1. Interim Functional and Cardiac Data
Seven pivotal dose participants (2x10^14 GC/kg) aged 6–12 showed an average +4.9-point gain on the North Star Ambulatory Assessment at one year versus projected decline, with older participants (8+) improving +5.2 points. Cardiac MRI endpoints including left ventricular ejection fraction (61.7% to 61.6%), global circumferential strain, and fibrosis remained stable at 12 months.
2. Biomarker and Safety Profile
Biomarker assessments demonstrated consistent microdystrophin expression exceeding 10%, with one patient showing 51.2% expression at Week 12. No serious adverse events or adverse events of special interest were reported; liver markers (GGT, bilirubin) remained within normal limits and muscle enzyme levels declined over one year.
3. Next Steps and Regulatory Timeline
Topline pivotal data for the Phase I/II AFFINITY DUCHENNE trial are scheduled for early Q2 2026, followed by a pre-BLA meeting with regulators mid-2026. The confirmatory trial continues enrollment of approximately 30 participants aged 1 and above, targeting majority enrollment by BLA submission.