BETHESDA, Md.--(BUSINESS WIRE)--REGENERX BIOPHARMACEUTICALS, INC. (AMEX:RGN) (www.regenerx.com) announced that it has filed an Investigational New Drug Applications (IND) with the U.S. FDA requesting permission to begin a Phase 2 clinical trial to evaluate the safety and wound healing efficacy of a Thymosin beta 4 (Tß4) eye drop formulation in patients recovering from ophthalmic surgery. The company may initiate the study 30 days after filing the IND if it does not otherwise hear from the agency.