Regenxbio announced the clearance of the Investigational New Drug (IND) application by the U.S. Food and Drug Administration (FDA) to evaluate the suprachoroidal delivery of RGX-314 in patients with diabetic retinopathy (DR). The IND is active, and Regenxbio plans to begin dosing patients in a Phase II trial, ALTITUDE, in the second half of 2020.

"Diabetic retinopathy is the leading cause of blindness in patients 24 to 75 years of age and affects approximately 8 million people in the United States alone. Without treatment, a large proportion of patients with DR develop proliferative disease and vision threatening complications, including center-involved diabetic macular edema. We believe one-time treatment with RGX-314 can provide sustainable, long-term anti-VEGF delivery to the eye, potentially reducing the severity of DR and preventing vision threatening complications," said Steve Pakola, M.D., Chief Medical Officer of REGENXBIO. "We are pleased to advance this program, and look forward to initiating our second clinical trial utilizing suprachoroidal delivery, building upon clinical and preclinical data from the RGX-314 program."

ALTITUDE is a multi-center, open label, randomized, controlled dose-escalation study that will evaluate the efficacy, safety and tolerability of suprachoroidal delivery of RGX-314. The trial is expected to enroll 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 study 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 interim data from this trial in 2021.

RGX-314 is being developed as a potential one-time treatment for wet AMD, diabetic retinopathy, and other additional chronic retinal conditions treated with anti-VEGF. RGX-314 consists of the NAV AAV8 vector encoding an antibody fragment which is designed to inhibit VEGF, modifying the pathway for formation of new leaky blood vessels which lead to retinal fluid accumulation and vision loss.

Diabetic retinopathy (DR) is the leading cause of vision loss in adults between 24 and 75 years of age worldwide. DR affects approximately 8 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.