Regenerx Biopharmaceuticals, Inc. has announced that its ophthalmic drug candidate, RGN-259, was used to treat four neurotrophic keratitis patients with non-healing eye ulcers caused primarily by the herpes zoster virus under a “Compassionate Use” IND (Investigational New Drug application). RGN-259 is a sterile eye drop formulation of Tβ4 being developed by RegeneRx for use in treating ophthalmic wounds and related disorders. In all four patients, the eye ulcers either completely healed or demonstrated significant improvement by treatment day 28, the maximum treatment period allowed under the clinical protocol.