First Patient Enrolled into U.S. Phase 3 Neurotrophic Keratitis Clinical Trial with RGN-259

ROCKVILLE, Md., April 13, 2023 /PRNewswire/ -- RegeneRx Biopharmaceuticals, Inc. (OTCQB: RGRX) ("RegeneRx" or "Company"), a clinical-stage drug development company focused on tissue protection, repair, and regeneration, has announced that on April 12, the first patient of the Phase 3 clinical trial (SEER-2) of RGN-259, a novel treatment for neurotrophic keratitis (NK), has been enrolled and begun treatment.  The product candidate is under development by ReGenTree, LLC, a U.S. joint venture between RegeneRx and HLB Therapeutics.

Clinical results in patients with NK treated with RGN-259 have previously demonstrated efficacy in a small number of patients (18) in the first phase 3 clinical trial (SEER-1), and two clinical trials are underway simultaneously in the United States and Europe based on these results.

Two independent clinical trials showing statistically significant safety and efficacy are required for marketing approval in the U.S. ReGenTree aims to significantly shorten the clinical development period by conducting the two phase 3 clinical trials (SEER-2 and SEER-3) at the same time, rather than sequentially.  The double-masked, placebo-controlled trials will be conducted by administering RGN-259 or placebo eye drops for four weeks to approximately 70 NK patients in each trial, with a primary endpoint of "complete corneal healing." Considering it is a rare disease, ReGenTree plans to recruit more than 30 clinical institutions in the U.S. to accelerate patient recruitment.

RGN-259, whose active ingredient is thymosin beta 4 (Tβ4), is a novel drug candidate that promotes cell migration, anti-inflammation, and wound healing. RGN-259 is formulated as a sterile, preservative-free eyedrop and has been shown to be safe and well-tolerated.

Neurotrophic keratitis offers a relatively large market opportunity as a rare disease with about 20,000 patients a year in the United States. Oxervate, from Dompé farmaceutici in Italy, is currently the only approved treatment for NK in the United States and is one of the most expensive pharmacy drugs in the U.S.

Regarding the clinical development of RGN-259 for dry eye syndrome, HLB Therapeutics noted that ReGenTree applied for SPA (Special Protocol Assessment) to the FDA in October of 2022, and has since been closely discussing clinical design, statistical analysis plans, and approval requirements with the FDA. SPA is a system whereby a sponsor consults with FDA in advance on clinical protocols and statistical analysis plans to increase the possibility of new drug approval. According to HLB, its strategy is to increase clinical design completeness and reduce uncertainty in the future as it believes RGN-259 will be an important clinical product for dry eye treatment given its past clinical results.

Forward-Looking Statements

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SOURCE RegeneRx Biopharmaceuticals, Inc.

For further information: RegeneRx: 301.208.9191, jjfnk@regenerx.com