RegeneRx Biopharmaceuticals (AMEX:RGN) reported today that researchers at the National Institutes of Health (NIH) found that TB4, administered to wounds in laboratory animals, significantly increased several important wound healing proteins called matrix metalloproteinases (MMPs), including MMP-2 and MMP-9. The researchers surmised that it is likely that other proteinases may also be regulated (up or down) by TB4. The paper, Thymosin B4 Promotes Matrix Metalloproteinase Expression During Wound Repair, was published in the Journal of Cellular Physiology, (D. Philp, et al., 208:195:200; 2006).

Matrix metalloproteinases are important for normal wound healing. These proteins clean wound debris, stimulate cell migration to the wound site, and help remodel collagen fibers to complete the healing process. It is also known that the level and type of proteinases are very important in wound repair. MMP-2 and MMP-9, two of over 25 identified MMPs, are specifically found in fibroblasts and keratinocytes, two cell types intimately involved in the would healing process.

According to Dr. Hynda Kleinman, in whose laboratory the research was performed, "these data demonstrate an additional mechanism by which TB4 may promote wound repair. This protein (TB4) may thus accelerate repair by multiple, related, and in some cases, interdependent mechanisms involving cell migration, angiogenesis, inflammatory response and protease production and activity."

Thymosin Beta 4

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. Additionally, TB4 directly influences the production of laminin-5, a protein responsible for proper adhesion and migration of certain types of mammalian cells and often deficient in patients with EB. It has also recently been reported that TB4 can inhibit or prevent apoptosis (programmed cell death) in ocular tissue and cardiac tissue. 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. An article was published in the scientific journal, Nature, indicating that TB4 protects heart tissue following a myocardial infarction (heart attack) 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.

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, 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 a therapeutic platform. RegeneRx holds over fifty world-wide patents and patent applications related to dermal, ocular, and internal wounds and tissue repair, cardiac and neurological injuries, and septic shock. RegeneRx is currently sponsoring three Phase II chronic dermal wound healing clinical trials and has additionally targeted ophthalmic and cardiac trials in 2006 as part of its ongoing clinical development program.

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.

For more information please visit RegeneRx's web site at www.regenerx.com.