Phase III SEER-1 trial of RGN 259 shows efficacy in neurotrophic keratopathy.- ReGenTree + RegeneRx Biopharma

ReGenTree, a U.S. joint venture company owned by GtreeBNT Co. and RegeneRx Biopharmaceuticals, announced the results of a randomized, double masked, placebo-controlled Phase III clinical trial (SEER-1) using RGN 259 for the treatment of neurotrophic keratopathy (NK). The study originally planned to recruit 46 patients using RGN 259, the same eye drop formulation used in the dry eye trials. However, because of slow patient recruitment and future pricing strategy for NK as a rare disease, the trial was closed early and 18 patients were analyzed.

Six out of 10 patients in the RGN 259 treated group and 1 out of 8 patients in the placebo treated group achieved complete corneal healing in 4 weeks. In terms of the primary endpoint, “ratio of corneal wound healed patients after four weeks’ administration”, the statistical difference was slightly over 0.05 (p = 0.0656, Fisher’s exact test), due to the limited number of patients in each group. When another statistical analysis method was used to analyze the same primary endpoint (Chi square test), there was statistical significance, p = 0.0400.

In addition, in a pre-specified secondary endpoint evaluating corneal epithelial healing at day 43 (two weeks post treatment) and the durability of RGN 259 treatment, we also confirmed a clear statistical difference using the Fisher’s exact test, p = 0.0359. Several other efficacy parameters were either highly significant or strongly trending toward statistical significance in the RGN 259 group indicating the depth of patient response to RGN 259.

Comment: On April 30, 2020, the Company met with the FDA for a discussion about future development directions and received a positive assessment of Biologics License Application (BLA) readiness for non-clinical animal testing, manufacturing methods, and quality control. A discussion on clinical design and trial requirements for BLA approval was also reviewed.