Dr. Gabriel Sosne to Present New TB4 Data at 2007 ARVO Meeting.

Data Continues to Support Tb4's Potent Anti-Inflammatory Capabilities

BETHESDA, Md. -- REGENERX BIOPHARMACEUTICALS' (AMEX: RGN), www.regenerx.com - Dr. Gabriel Sosne will be speaking at the 2007 Association for Research in Vision and Ophthalmology (ARVO) meeting in Ft. Lauderdale, Florida

on May 9th to discuss Tb4's ability to inhibit corneal neutrophil infiltration. Neutrophil infiltration is a process closely associated with inflammation that, if not properly controlled, can cause substantial tissue and organ damage. According to Dr. Sosne, Tb4 inhibits neutrophil infiltration by decreasing and/or suppressing the expression of several different types of inflammatory molecules, some of which have been previously identified and the subject of several ophthalmic publications.

"The importance of this finding is that it gives us a better understanding of the pathway Tb4 uses to reduce inflammation and increases the clinical relevance of Tb4 as we translate the work from the laboratory bench into patients. Our understanding of the neutrophil connection applies not only to Tb4's mechanism of action in eye wounds, but likely also at organ and tissue sites such as the skin and heart, among others," said Dr. Sosne, Assistant Professor of Ophthalmology at Wayne State University and the Kresge Eye Institute in Detroit, Michigan.

About RegeneRx Biopharmaceuticals, Inc.

RegeneRx is focused on the discovery and development of novel molecules to accelerate tissue and organ repair. Currently, RegeneRx is developing Tb4, a 43 amino acid peptide, in part, under an exclusive world-wide license from the National Institutes of Health. Preliminary research suggests that Tb4 may prove efficacious for multiple indications; therefore, RegeneRx is developing Tb4 as the cornerstone of its therapeutic platform. The technology platform has many potential applications in both the pharmaceutical and consumer products sectors. RegeneRx holds nearly 60 world-wide patents and patent applications related to dermal, ocular, and internal wounds and tissue repair, cardiac and neurological injuries, septic shock and several consumer product areas. RegeneRx is currently sponsoring three Phase 2 chronic dermal wound healing clinical trials and has been cleared by the FDA to initiate ophthalmic and cardiovascular clinical trials as part of its ongoing clinical development program.

The RegeneRx Technology Platform

Tb4 is a synthetic version of a naturally occurring peptide present in virtually all human cells. It is a first-in-class drug candidate that promotes endothelial cell differentiation, angiogenesis in dermal tissues, keratinocyte migration, collagen deposition, and down-regulates inflammation. One of Tb4's key mechanisms of action is its ability to regulate the cell-building protein, actin, a vital component of cell structure and movement. Of the thousands of proteins in cells, actin represents up to 10% of the total protein and, thus, plays a major role in the physiology of the cell. RegeneRx has identified several molecular variations of Tb4 that may affect the aging of skin, among other properties, and could be important candidates as active ingredients in pharmaceutical and consumer products. Researchers at the National Institutes of Health, and at other academic institutions throughout the U.S., have published numerous scientific articles indicating that Tb4 is effective in accelerating dermal and corneal wound healing in several animal models, under a variety of conditions. In two articles published in the scientific journal, Nature, researchers found that Tb4 protects heart tissue following a myocardial infarction (heart attack) and can regenerate coronary vessels in laboratory animals. Abstracts of scientific papers related to Tb4's mechanisms of action may be viewed at RegeneRx's web page: www.regenerx.com.

Safe Harbor Statement

The information in this press release may include certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements concern the Company's current expectations regarding future events, including the ongoing and prospective development of Tb4 and possible future benefits to the Company, its shareholders, and patients. Due to the nature of product development and the regulatory approval process, the forward-looking statements are subject to risks and uncertainties, including those reflected in the Company's filings with the Securities and Exchange Commission, particularly its most recent Annual Report on Form 10-KSB. The Company assumes no obligation to update or revise any forward-looking statements made herein or any other forward-looking statements made by the Company.