REGENXBIO Doses First Patient in RGX-314 Trial for Diabetic Retinopathy

REGENXBIO announced the first patient has been dosed in ALTITUDE, a Phase II trial to evaluate the suprachoroidal delivery of RGX-314 using the SCS Microinjector for the treatment of diabetic retinopathy (DR).

"We are pleased to announce the first patient dosed in our ALTITUDE trial, an important milestone as we continue to evaluate the overall clinical profile of RGX-314 for the treatment of chronic retinal conditions. This is our second Phase II trial using the in-office suprachoroidal delivery approach, which may allow physicians to treat patients with diseases like DR earlier in the disease course," said Steve Pakola, M.D., Chief Medical Officer of REGENXBIO. "Long-term treatment with anti-VEGF injections has been shown to significantly reduce disease progression and severity of DR, even in patients who are asymptomatic, as well as prevent vision threatening complications. We believe that one-time treatment with anti-VEGF gene therapy can have a meaningful impact for patients with DR, and we look forward to providing additional updates from this trial next year."

"DR is the most common cause of vision loss among patients with diabetes, with an average age of disease onset between 45-50 years old. Anti-VEGF injections have been approved by the FDA for diabetic retinopathy, but treatment with anti-VEGF agents requires frequent clinic visits and injections. RGX-314 may provide sustainable, long-term anti-VEGF protein production in the eye, which could be a one-time treatment option for working-age adults," said Arshad M. Khanani M.D., M.A., trial investigator and director of clinical research at Sierra Eye Associates.

ALTITUDE is a multi-center, open label, randomized, controlled dose-escalation trial that will evaluate the efficacy, safety and tolerability of suprachoroidal delivery of RGX-314. The trial is expected to enroll approximately 40 patients with DR across two cohorts. Patients will be randomized to receive RGX-314 versus observational control at a 3:1 ratio, and two dose levels of RGX-314 will be evaluated: 2.5x1011 GC/eye and 5.0x1011 GC/eye. Patients will not receive prophylactic immune suppressive corticosteroid therapy before or after administration of RGX-314.

The primary endpoint of the trial is the proportion of patients that improve in DR severity based on the Early Treatment Diabetic Retinopathy Study-Diabetic Retinopathy Severity Scale (ETDRS-DRSS) at 48 weeks. Other endpoints include safety and development of DR-related ocular complications.

The Company expects to report initial data from this trial in 2021.

RGX-314 is being developed as a potential one-time treatment for wet AMD, diabetic retinopathy, and other chronic retinal conditions. RGX-314 consists of the NAV AAV8 vector, which encodes an antibody fragment designed to inhibit vascular endothelial growth factor (VEGF). RGX-314 is believed to inhibit the VEGF pathway by which new, leaky blood vessels grow and contribute to the accumulation of fluid in the retina.

REGENXBIO is advancing two separate routes of administration of RGX-314 to the eye, through a standardized subretinal delivery procedure as well as delivery to the suprachoroidal space. REGENXBIO has licensed certain exclusive rights to the SCS Microinjector® from Clearside Biomedical, Inc. to deliver gene therapy treatments to the suprachoroidal space of the eye.

Diabetic retinopathy (DR) is the leading cause of vision loss in adults between 24 and 75 years of age worldwide. DR affects approximately eight million people in the United States alone. The spectrum of DR severity ranges from non-proliferative diabetic retinopathy (NPDR) to proliferative diabetic retinopathy (PDR) and as DR progresses, a large proportion of patients develop vision threatening complications, including diabetic macular edema (DME) and neovascularization that can lead to blindness. Current treatment options for patients with DR include "watchful waiting", anti-VEGF treatment, retinal laser or surgical treatment. Anti-VEGF treatments have been shown to reduce the severity of DR and prevent vision threatening complications by at least 75% in patients with moderately severe to severe NPDR.