Researchers at the Hawaiian Eye and Retina meeting in Maui has reported positive 6-month results for RGX-314, for the treatment of wet AMD, using a suprachoroidal delivery system proposed for an office treatment to stabilize or improve vision long-term for wet AMD patients, subject to approval. The experimental treatment, is to be proposed as potential “one-time treatment for wet AMD, diabetic retinopathy, and other chronic retinal conditions”. RGX-314 consists of an AAV8 vector, which encodes an antibody fragment designed to inhibit vascular endothelial growth factor (VEGF).
RGX-314 is being developed using an AAV8 vector encoding an antibody fragment designed to inhibit vascular endothelial growth factor (VEGF). Two separate routes of administration of RGX-314 use a standardized subretinal delivery procedure as well as delivery to the suprachoroidal space. A microinjector medical device from Clearside Biomedical, Inc. is aimed to deliver the proposed gene therapy treatment to the suprachoroidal space. The dose-escalation trial, evaluating the efficacy, safety and tolerability of suprachoroidal delivery of RGX-314, is conducted in patients with a wet-AMD diagnosis. The primary endpoint of the trial is mean change in vision in patients dosed with ABBV-RGX-314, as measured by BCVA at week 40 from baseline, compared to patients receiving monthly injections of ranibizumab. Other endpoints include mean change in CRT and the number of anti-VEGF intravitreal injections received following administration of RGX-314. As reported of November 6, 2023, RGX-314 suprachoroidal delivery was well tolerated across 106 patients from three dose levels. No drug-related SAEs were reported. All treatment emergent adverse events (TEAEs) through 6 months in the study eye were mild or moderate and included conjunctival hemorrhage, increased intraocular pressure, episcleritis, and conjunctival hyperemia. Mild intraocular inflammation was reported at similar incidence rate in the first and second dose levels, with mild to moderate intraocular inflammation seen at the third dose level. Patients have been dosed across three dose levels: 2.5×1011 (Cohort 1), 5×1011(Cohorts 2 and 3), and 1×1012 (Cohorts 4-6) genomic copies per eye (GC/eye). According to the interim results, patients treated with RGX-314 continue to demonstrate stable BCVA and CRT at six months. In addition, a meaningful reduction in anti-VEGF treatment burden was observed following administration of RGX-314.
In highlighting the interim data, with sponsors Regenxbio and AbbVie, the retina meeting reported that “RGX-314 continues to be well tolerated in over 100 patients from three dose levels with no drug-related serious adverse events”. The Chief Medical Officer of Regenxbio (RGNX), Dr. Steve Pakola, M.D., stated that RGX-314 “continues to be well tolerated in patients with wet AMD. We are pleased that dose level 3 in this trial has shown the highest reduction in treatment burden with zero cases of inflammation observed in patients who received prophylactic short-course topical steroids. We are encouraged by this data as part of the global RGX-314 program.”