Pivotal Phase III Primary Endpoint Met
AFFINITY DUCHENNE pivotal Phase III met its primary endpoint with high statistical significance: 93% (28 of 30 biopsied patients) exceeded the predefined microdystrophin >10% threshold. Interim safety available for 31 dosed pivotal patients.
Robust Microdystrophin Expression
Very high biomarker expression: 71.1% average microdystrophin across all patients, 80% of patients >40% expression, and 41.6% average expression in patients aged ≥8. Company noted among the highest vector copy numbers and product purity (cited >80% full capsids).
Strong Biomarker–Clinical Correlation
A highly statistically significant correlation between microdystrophin expression and functional improvement was reported: correlation coefficients >0.9 for both NSAA change from baseline and NSAA vs cTAP predicted value, supporting microdystrophin as a surrogate endpoint likely to predict clinical benefit.
Interim 12‑Month Functional Improvements vs External Controls
Interim 12‑month functional data (9 ambulatory patients aged ≥4) showed improvement across NSAA and timed function tests versus external controls (propensity-score weighted analyses). Caregiver-reported PODCI measures also improved. Clinical investigators corroborated meaningful functional gains and real-world patient videos were shared (1–2 year improvements).
Generally Favorable Safety Profile with Proactive Immunosuppression
RGX-202 was described as well tolerated: of 31 dosed patients there were 2 treatment-related SAEs (both resolved without sequelae: one subacute myocarditis and one asymptomatic liver injury). No drug-related thrombocytopenia, myositis or neurotoxicity were reported. Mean GGT and total bilirubin remained stable and well below upper limits of normal across 12 months.
Pipeline Progress, Enrollment and Near‑Term Commercial Planning
More than 50 patients dosed across pivotal and confirmatory studies with line of sight to dose ~60 patients by midyear. Company is planning for potential accelerated approval and commercial filing targeting 2027. Additional program highlights: retinal Phase IIb first‑patient dosing expected Q2 (triggers $100M AbbVie milestone), partial clinical hold on RGX-121 lifted, appeal of RGX-121 CRL filed, and company targeting three approvals over the next couple of years including two potential blockbusters.