REGENXBIO reports three-year ALTITUDE data showing sustained DRSS improvement with investigational sura-vec gene therapy in non-proliferative diabetic retinopathy.
Written By: Charvi Kalal, PharmD
Reviewed By: Pharmacally Editorial Team
REGENXBIO reported three-year follow-up from the Phase II ALTITUDE trial (NCT04567550) of investigational surabgene lomparvovec (sura-vec, ABBV-RGX-314) in non-proliferative diabetic retinopathy (NPDR), with 60% of evaluable Dose Level 3 participants achieving more than a two-step improvement in Diabetic Retinopathy Severity Scale (DRSS) without additional treatment for diabetic retinopathy.
Three-Year Efficacy Signals in NPDR
The long-term analysis included Dose Level 3 participants who received a single suprachoroidal administration of sura-vec at 1.0 × 10¹² genome copies (GC) per eye, followed by a short course of prophylactic topical steroids. Among the 10 Dose Level 3 participants with three-year efficacy assessments, six achieved a greater than two-step improvement in DRSS without supplemental treatment for diabetic retinopathy.
None of these participants experienced a vision-threatening event during follow-up.
The data, collected through August 17, 2026, also showed sustained improvement among participants who responded earlier in treatment. Three of four participants who achieved a one-step DRSS improvement at one year without supplemental anti-VEGF injections subsequently reached a greater than two-step improvement by year three without additional treatment for diabetic retinopathy.
Safety Profile Remained Consistent
The safety analysis covered a broader cohort of 17 participants evaluated through three years. No new sura-vec-related safety signals emerged during long-term follow-up, and no intraocular inflammation was observed with the short-course topical steroid regimen.
The findings are relevant to the safety profile of suprachoroidal delivery, which administers the gene therapy into the space between the sclera and choroid rather than directly into the vitreous cavity.
VEGF Inhibition Through Gene Therapy
Sura-vec uses the NAV AAV8 vector to deliver a transgene encoding an antibody fragment that inhibits vascular endothelial growth factor (VEGF). VEGF contributes to abnormal blood vessel growth and vascular leakage that drive retinal damage and vision-threatening complications.
By enabling sustained intraocular production of a VEGF-inhibiting protein after a single administration, the approach is being evaluated as a potential alternative to repeated anti-VEGF injections.
NPDR can progress to proliferative diabetic retinopathy (PDR), diabetic macular edema and retinal neovascularization. Current management of NPDR can include observation or anti-VEGF therapy, while PDR may require anti-VEGF treatment, retinal laser therapy or surgery in advanced disease.
Phase IIb/III Development Continues
REGENXBIO is evaluating the Dose Level 3 regimen in the Phase IIb/III NAAVIGATE trial in patients with NPDR. The three-year ALTITUDE findings provide longer-term clinical data for assessing whether a single administration can produce sustained changes in retinal disease severity without repeated treatment.
REGENXBIO Chief Medical Officer Steve Pakola, M.D., said the three-year results showed continued DRSS improvement alongside reduced disease progression. ALTITUDE investigator Nikolas London, M.D., FACS, FASRS, emphasized the potential clinical value of intervening before NPDR develops into vision-threatening disease.
The ALTITUDE findings remain investigational and require confirmation in the ongoing Phase IIb/III NAAVIGATE trial before the efficacy and safety of the Dose Level 3 regimen can be established.
Reference
REGENXBIO Presents Positive Three-Year Durability Data for Surabgene Lomparvovec in Diabetic Retinopathy at Retina Society Annual Scientific Meeting, REGENXBIO, 24 September 2026
RGX-314 Gene Therapy Administered in the Suprachoroidal Space for Participants With Diabetic Retinopathy (DR) With and Without Center Involved-Diabetic Macular Edema (CI-DME) (ALTITUDE®), ClinicalTrials.gov ID NCT04567550
About the Writer
Charvi Kalal (LinkedIn) is a Pharm.D intern and aspiring medical writer with hands-on experience in medical writing, clinical research, pharmacovigilance, and clinical pharmacy. She has experience in medical content writing through CliMed, along with exposure to ADR monitoring, prescription analysis, patient counselling, literature review, and research documentation. Her research focuses on ADR monitoring and reporting in breast cancer patients receiving targeted therapy. With certifications in GCP, biomedical research, scientific writing, and clinical research, she is passionate about transforming scientific evidence into accurate, engaging, and accessible healthcare content.