RegeneRx Biopharmaceuticals Inc. that its U.S. joint venture (JV) partner and licensee, HLB Therapeutics (HLBT), has announced that it submitted a protocol for its second phase 3 clinical trial (SEER-2) to the U.S. FDA on September 26th, evaluating RGN-259 as a treatment for neurotrophic keratopathy (NK). NK is being developed by ReGenTree, a U.S. joint venture company between RegeneRx Biopharmaceuticals Inc. and HLB Therapeutics. The following is the text of HLB's with a few edits and modifications for clarification.

In July, HLB announced that it signed a contract with a global CRO to simultaneously conduct SEER-2 as the second phase 3 clinical trial in the U.S. and SEER-3 as the third phase 3 clinical trial in the U.S. and Europe to obtain an approval for NK treatment as soon as possible. The clinical study design of SEER-2 and SEER-3 is based on the results of the first phase 3 clinical trial (SEER-1), where the number of subjects was relatively small, but good results were obtained. In the SEER-2 and SEER-3 studies, approximately 70 patients will be recruited in each study to evaluate efficacy, in particular complete healing after 4 weeks treatment.

In the U.S., ReGenTree is seeking clinical trial sites by contacting more than 70 ophthalmic hospitals and clinics and aims to start its first site in November. For the SEER-3 clinical trial, which will be conducted simultaneously in the U.S. and Europe, the study site selection process is ongoing by ReGenTree among 80 candidate sites in six European countries, and preparation of applications to be filed through CTIS (Clinical Trials Information System) is also underway. NK is a degenerative disease that reduces the sensitivity of the cornea and in severe cases worsens to corneal perforation, and is a rare disease that occurs in about five per 10,000 people in the U.S. So far, the only treatment approved is Italian pharma company, Dompé's Oxervate, a recombinant form of human nerve growth factor whose cost is extremely high for eight weeks of treatment.

The RGN-259 previously received an orphan drug designation for the treatment of NK from FDA, and a distinguished difference from many rare diseases is that the market is very significant. Due to the prevalence of NK patients who must be treated despite the high cost of drugs, the market is expected to be USD 324.0 million in 2027. One of goals in SEER-2 and SEER-3 is to successfully complete treatment within four weeks.

The company [ReGenTree] plans to drastically shorten the development period of RGN-259 by conducting the two phase 3 clinical trials (SEER-2, SEER-3) in the U.S. and Europe simultaneously [rather than sequentially]. Therefore, HLB Therapeutics is focusing all of its capabilities to achieve the possibility of applying for FDA BLA application in 2025 as an ultimate goal in its NK project.