Rockville, Md. – September 24, 2026 -- REGENXBIO Inc. (Nasdaq: RGNX) reported that 60% of Dose Level 3 participants with three-year follow-up data in its Phase II ALTITUDE study achieved a greater-than-2-step improvement on the Diabetic Retinopathy Severity Scale (DRSS) after a single in-office treatment with investigational gene therapy sura-vec, with no vision-threatening events recorded among responders.