Single Gene Therapy Injection Holds Diabetic Eye Disease at Bay for Three Years
REGENXBIO's one-time gene therapy turned 60% of trial patients' eyes into self-sustaining VEGF blockers, with no vision-threatening events over three years.
Summary
REGENXBIO reported three-year data from its Phase II ALTITUDE trial of surabgene lomparvovec, a gene therapy for non-proliferative diabetic retinopathy. A single in-office injection uses a viral vector to instruct retinal cells to continuously produce an anti-VEGF antibody fragment, replacing the need for repeated injections. Among the ten patients at the highest dose level with three-year follow-up, 60% improved by two or more steps on the standard disease severity scale, and none required additional retinopathy treatment or experienced vision-threatening events. The therapy targets a leading cause of vision loss in working-age adults, and the dose is now advancing into a larger Phase IIb/III trial called NAAVIGATE.
Detailed Summary
Diabetic retinopathy is the leading cause of vision loss in adults aged 24 to 75 worldwide, and its standard treatments — repeated anti-VEGF injections — demand ongoing clinic visits that many working-age patients struggle to sustain. REGENXBIO is betting that one treatment could replace years of injections, and its latest data offer an early but notable proof of concept.
The company presented three-year follow-up results from its Phase II ALTITUDE trial of surabgene lomparvovec (sura-vec, also known as ABBV-RGX-314, co-developed with AbbVie) at the Retina Society's 59th Annual Scientific Meeting. Sura-vec uses an adeno-associated viral vector delivered in a single in-office procedure to transfect retinal cells, which then continuously produce an antibody fragment that blocks VEGF — the protein driving abnormal, leaky blood-vessel growth in the retina.
Among the ten patients treated at Dose Level 3 who completed three-year visits, six (60%) improved by two or more steps on the Diabetic Retinopathy Severity Scale. None needed additional retinopathy treatment, and none experienced vision-threatening events. Across all 17 participants followed for three years, investigators observed no intraocular inflammation and no new safety signals linked to the therapy. Encouragingly, three of four patients who had shown only a one-step improvement at year one reached the two-step threshold by year three without further intervention.
The practical implication is significant: if durable efficacy is confirmed in larger studies, a single treatment could dramatically reduce the monitoring and injection burden for millions of patients with diabetes-related eye disease, potentially preserving functional vision and quality of life well into older age.
Caveats are real. Ten patients is an extremely small cohort, results are interim and company-reported, and 40% of participants did not reach the primary improvement threshold. One patient received supplemental injections for a protocol-adjacent reason and was then lost to follow-up. Dose Level 3 is now being evaluated in the larger Phase IIb/III NAAVIGATE trial, whose data will be far more definitive.
Key Findings
- 60% of patients (6/10) improved by 2+ steps on the diabetic retinopathy severity scale three years after one injection.
- No patients required additional retinopathy treatment or experienced vision-threatening events over three years.
- Three of four patients with only a one-step gain at year one progressed to a two-step gain by year three without retreatment.
- No intraocular inflammation or new safety signals were observed across all 17 participants followed for three years.
- Dose Level 3 is advancing to the larger Phase IIb/III NAAVIGATE trial in the same patient population.
Methodology
This is a news report summarizing interim, company-reported Phase II trial data (ALTITUDE trial) presented at a scientific meeting rather than peer-reviewed publication. The evidence basis is a small interim analysis (n=10 at the key dose level) conducted by the sponsor; independent verification has not yet occurred. Results should be interpreted with caution until published in a peer-reviewed journal and confirmed in the ongoing Phase IIb/III NAAVIGATE trial.
Study Limitations
The key efficacy analysis covers only ten patients, making percentages statistically fragile and susceptible to individual variation. Data are interim and company-generated, not yet peer-reviewed or independently validated. The fate of the 40% who did not improve by two steps is unreported, and one participant was lost to follow-up after a protocol-adjacent intervention.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.
Enter your email to subscribe: