Gene therapy reduced the need for need for supplemental anti-VEGF injections by 97% and maintained key measures of eye health.
Gene therapy developer RegenxBio has announced encouraging data from a Phase 2 sub-study designed to assess the efficacy of its lead therapy in patients with bilateral wet age-related macular degeneration (AMD). Wet AMD is a severe form of macular degeneration characterized by the abnormal growth of blood vessels in the retina, leading to vision loss. Affecting up to 2 million people in the United States, Europe, and Japan, wet AMD is a significant cause of blindness.
RegenxBio’s gene therapy, inventively named ABBV-RGX-314, is being developed in collaboration with pharma giant AbbVie as a potential one-time treatment for wet AMD and other retinal conditions, including diabetic retinopathy. ABBV-RGX-314 employs the NAV AAV8 vector, which encodes an antibody fragment designed to inhibit vascular endothelial growth factor (VEGF), a protein responsible for the formation of new, leaky blood vessels in the retina. The treatment aims to reduce fluid accumulation in the retina by blocking VEGF, potentially providing long-term benefits.
Current wet AMD treatments, such as anti-VEGF therapies, require frequent and lifelong intraocular injections to prevent vision deterioration. These regimens pose significant challenges for patients, as adherence can decline over time, potentially reducing their effectiveness.
“The majority of our patients with wet AMD eventually have bilateral disease and face a substantial treatment burden with frequent lifelong injections in both eyes,” said Dr Arshad Khanani, director of clinical research at Sierra Eye Associates in Reno, NV. “This leads to suboptimal real-world vision outcomes with current standard of care.”
In the Phase 2 sub-study, ABBV-RGX-314 demonstrated promising results nine months after administration, leading to a 97% reduction in the need for supplemental anti-VEGF injections, with 100% of patients requiring either no injections or just one additional injection during the study period. Notably, 78% of patients were completely injection-free. In addition to this reduction in treatment burden, patients maintained stable best-corrected visual acuity and central retinal thickness, two key measures of eye health. Furthermore, aqueous protein levels, a marker of disease activity, were consistent between the treated eyes.
“The fellow eye dosing data with ABBV-RGX-314 is a milestone for the field of gene therapy for common retinal diseases, as this is the first time we have performed bilateral treatment for wet AMD patients,” added Khanani, who presented the data at the recent American Academy of Ophthalmology meeting. “These results, combined with the durable treatment effect up to four years shown in long-term follow up, highlight the potential of ABBV-RGX-314 as a one-time effective treatment option for patients with wet AMD.”
