Benzinga | Oct 11, 2021 09:59AM EDT

REGENXBIO Saturday Morning Highlighted Presentation Of Initial Data From Phase 2 ALTITUDE Trial Of RGX-314 For Treatment Of Diabetic Retinopathy Using Suprachoroidal Delivery At American Society Of Retina Specialists Meeting

* Suprachoroidal delivery of RGX-314 well tolerated in 15 patients in Cohort 1 with no drug-related serious adverse events No intraocular inflammation observed

* Positive interim data update from Cohort 1 at three months after one-time treatment of RGX-314 33% of patients demonstrated a ?2 step improvement from baseline on the ETDRS-DRSS compared to 0% of patients in observational control

* Cohorts 2 and 3 continue to enroll patients at a dose level of 5x1011 GC/eye

REGENXBIO Inc. (NASDAQ:RGNX) today announced initial data from the ongoing Phase II ALTITUDE(tm) trial of RGX-314 for the treatment of diabetic retinopathy (DR) without center-involved diabetic macular edema (CI-DME) using in-office suprachoroidal delivery. The data is being presented at the American Society of Retina Specialists (ASRS) Annual Meeting by Dennis Marcus, M.D., F.A.S.R.S., President, Southeast Retina Center. RGX-314 is a potential one-time gene therapy in clinical development for the treatment of wet age-related macular degeneration and DR.

"We are pleased to share initial data from the Phase II ALTITUDE trial, and we are encouraged to see treatment effect particularly at this early time point of three months after the one-time, in-office administration of RGX-314," said Steve Pakola, M.D., Chief Medical Officer of REGENXBIO. "RGX-314 is the first gene therapy in clinical trials for DR using suprachoroidal delivery, and has the potential to provide sustainable, long-term anti-VEGF protein production in the eye for the treatment of DR, which affects approximately eight million people in the United States alone. We look forward to providing additional updates on this trial next year."

"DR can start in young adulthood and often progresses quickly, leading to vision-threatening complications, including diabetic macular edema (DME) and neovascularization that can lead to vision loss," said Dr. Marcus. "Current treatment options include 'watchful waiting,' treatment requiring repeated anti-VEGF injections, retinal laser or surgical treatment. This first look at the ALTITUDE trial data is promising, as it shows not only clinical improvement in disease severity as measured by the ETDRS-DRSS, but also that this treatment is well tolerated in patients."

Study Design and Safety Update from Phase II ALTITUDE Trial of RGX-314 for the Treatment of DR Using Suprachoroidal Delivery

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 using the SCS Microinjector(r) in patients with a DR diagnosis of moderately severe or severe nonproliferative diabetic retinopathy (NPDR) or mild proliferative diabetic retinopathy (PDR). Twenty patients in Cohort 1 were randomized to receive RGX-314 at a dose level of 2.5x1011 genomic copies per eye (GC/eye) versus observational control at a 3:1 ratio. Cohort 2 will include 20 patients randomized to receive RGX-314 at an increased dose level of 5x1011 GC/eye versus observational control at a 3:1 ratio. Cohort 3 is designed to evaluate RGX-314 at the same dose level as Cohort 2 in 20 patients who are neutralizing antibody (NAb) positive. Enrollment is ongoing in Cohorts 2 and 3. Patients in this trial do not receive prophylactic immune suppressive corticosteroid therapy before or after administration of RGX-314.

As of September 29, 2021, RGX-314 was reported to be well tolerated in the 15 patients dosed with RGX-314 in Cohort 1. One serious adverse event was reported in one patient dosed with RGX-314, which occurred in the patient's untreated fellow eye and is considered not related to RGX-314. Among patients in Cohort 1 dosed with RGX-314, no intraocular inflammation was observed on slit-lamp examination. One patient experienced a mild case of episcleritis that resolved with topical corticosteroids. Common ocular treatment emergent adverse events in the study eye were not considered drug-related and were predominantly mild. These included conjunctival hemorrhage and conjunctival hyperemia.

Summary of Data for Cohort 1 at Three Months

Of the 15 patients dosed with RGX-314 in Cohort 1, five patients (33%) demonstrated a two-step or greater improvement from baseline on the Early Treatment Diabetic Retinopathy Study-Diabetic Retinopathy Severity Scale (ETDRS-DRSS) at three months, compared to zero of the five patients (0%) in the observational control group. One patient dosed with RGX-314 had a four-step improvement.

In the seven patients who had NPDR (DR severity level 47-53) at baseline, three patients (43%) demonstrated a two-step or greater improvement at three months after administration of RGX-314. In the eight patients who had PDR (DR severity level ? 61) at baseline, two patients (25%) demonstrated a two-step or greater improvement at three months after administration of RGX-314.

Data presented today is available on the "Presentations and Publications" section of the REGENXBIO website at www.regenxbio.com.