Gene therapy reduces treatment burden, improves vision in wet AMD
SAN FRANCISCO — RGX-314 gene therapy demonstrated meaningful reductions in anti-VEGF injections and increases in visual acuity and central retinal thickness among patients with wet age-related macular degeneration, according to an update presented at Retina Subspecialty Day at the American Academy of Ophthalmology annual meeting.
“RGX-314 utilizes a proprietary gene delivery platform that is hypothesized to deliver longer and higher protein expression with a lower immune response,” Jeffrey S. Heier, MD, co-president and director of retina research at Ophthalmic Consultants of Boston, said during his presentation. “The AAV8 vector isn’t coded to deliver a gene that is for anti-VEGF monoclonal antibody fragment.”
Heier and colleagues conducted a phase 1/2a clinical trial to determine the safety and tolerability of RGX-314 for the treatment of wet AMD. Forty-two patients with wet AMD who were previously treated with anti-VEGF therapy were enrolled in the trial.
Participants received one of five doses of RGX-314, ranging from 3x10 GC/eye to 2.5x10¹¹ GC/eye. The therapy was administered via subretinal delivery. Change in anti-VEGF intravitreal injections, visual acuity, central retinal thickness and protein expression levels were assessed every month for 24 months.
Data from cohorts four and five have not been previously presented, Heier noted. These new data showed that both cohorts four and five had significant decreases in anti-VEGF injection burden and increases in best correct visual acuity and central retinal thickness at month 6.
RGX-314 appeared well tolerated among all cohorts. There were no serious safety concerns, including clinically determined immune responses and ocular inflammation.
“[The] interim update from the RGX-314 phase 1/2a dose escalation study further demonstrates the significant reduction in anti-VEGF treatment burden and encouraging improvement or maintenance of effects on vision and retinal thickness in the three higher dose cohorts,” Heier said in a press release.
“These effects are especially important as subjects in this study had been previously treated with chronic and burdensome anti-VEGF injections over several years, highlighting the severity of their disease,” he added. “[These] results further support the potential of RGX-314 gene therapy to have meaningful and durable effects in patients following a one-time intervention.” – by Alaina Tedesco
Reference: Heier JS. Results of cohorts 1-5 for the RGX-314 phase I/IIa study of gene therapy for neovascular wet AMD. Presented at: American Academy of Ophthalmology annual meeting; Oct. 11-15, 2019; San Francisco.
Disclosure: Heier reports serving as a scientific advisor to Regenxbio.