REGENXBIO Advances Gene Therapy to Pivotal Phase IIb/III Trial for Diabetic Retinopathy
Key Insights
REGENXBIO will initiate a pivotal Phase IIb/III clinical trial for surabgene lomparvovec (search) in diabetic retinopathy (search) using suprachoroidal delivery, following positive two-year safety and efficacy data from the Phase II ALTITUDE trial.
The gene therapy demonstrated durable safety with no drug-related serious adverse events and no intraocular inflammation through two years at the highest dose level with prophylactic steroids.
AbbVie (search) will pay REGENXBIO $100 million upon first subject dosed in the Phase IIb/III trial and an additional $100 million upon first subject dosed in a second Phase III trial under an amended collaboration agreement.
REGENXBIO Inc. announced it will initiate a pivotal Phase IIb/III clinical trial for investigational surabgene lomparvovec (search) (sura-vec (search), ABBV-RGX-314) in diabetic retinopathy (search) using suprachoroidal delivery. The advancement follows positive two-year data from the Phase II ALTITUDE trial and represents a significant milestone in developing a potential one-time gene therapy treatment for this leading cause of blindness.
"Advancing our DR program to late-stage development brings sura-vec (search) closer to being a potentially transformative new treatment for the millions of people living with DR," said Steve Pakola, M.D., Chief Medical Officer at REGENXBIO.
Phase II Trial Results Support Pivotal Program
The Phase II ALTITUDE trial demonstrated that sura-vec (search) was well tolerated in subjects with non-proliferative diabetic retinopathy (search) (NPDR) at dose levels 1, 2, and 3. As of June 9, 2025, there were no drug-related serious adverse events reported across all dose levels.
Notably, no intraocular inflammation was observed through two years at dose level 3 (1.0x10¹² GC/eye) in 15 subjects when administered with short-course topical prophylactic steroids. This safety profile supports the advancement to pivotal trials.
The upcoming pivotal two-part placebo-controlled Phase IIb/III trial will use dose level 3 data as the foundation, with the primary endpoint being greater than 2-step DRSS (Diabetic Retinopathy (search) Severity Scale) improvement at 1 year. Site selection for the global trial is currently in progress.
Expanded AbbVie Collaboration
AbbVie (search) and REGENXBIO executed an amendment to their collaboration and license agreement originally established on September 10, 2021. Under the updated milestone structure, AbbVie will pay REGENXBIO $100 million upon first subject dosed in the Phase IIb/III trial and an additional $100 million upon first subject dosed in a second Phase III clinical trial. REGENXBIO will cover all costs for the Phase IIb portion of the Phase IIb/III trial.
The amendment also reflects AbbVie (search)'s broader investment in the sura-vec (search) program. AbbVie will independently advance and fund a new Phase III ACHIEVE trial in wet age-related macular degeneration (search) (AMD). This randomized controlled trial will assess the potential reduction in injection burden and preservation of long-term vision of sura-vec compared to standard of care.
"We are excited to advance this clinical development program with the goal of helping to address these unmet needs and bring an additional option to patients living with DR," said Primal Kaur, M.D., Senior Vice President, Global Development of Immunology, Neuroscience, Eye Care and Specialty at AbbVie (search).
Addressing Significant Unmet Medical Need
Diabetic retinopathy (search) represents a substantial medical burden, affecting nearly 10 million people in the United States alone. The condition is the leading cause of vision loss in adults between 24 and 75 years of age worldwide. As DR progresses, a large proportion of patients develop vision-threatening complications, including diabetic macular edema (search) and neovascularization that can lead to blindness.
Current treatment options for patients with NPDR typically include "watchful waiting" or anti-VEGF (search) treatment. For patients with proliferative diabetic retinopathy (search) (PDR), current treatment options include anti-VEGF treatment or retinal laser, with surgical treatment potentially required for advanced PDR.
Gene Therapy Mechanism
Surabgene lomparvovec (search) consists of the NAV AAV8 vector, which encodes an antibody fragment designed to inhibit vascular endothelial growth factor (search) (VEGF (search)). The therapy is believed to inhibit the VEGF pathway by which new, leaky blood vessels grow and contribute to the accumulation of fluid in the retina.
The gene therapy is being investigated as a potential one-time treatment for wet AMD, diabetic retinopathy (search), and other chronic retinal conditions, representing a significant departure from current treatment paradigms that require frequent injections.