RegeneRx Completes Enrollment and Dosing of Phase I Safety Trial for Potential Heart Drug

Drug Candidate Appears Safe and Well-tolerated over 14 Days of IV Administration

BETHESDA, Md.--(BUSINESS WIRE)--REGENERX BIOPHARMACEUTICALS, INC. (NYSE Alternext US:RGN) announced today that it has completed enrollment and dosing of 40 healthy volunteers for its Phase IB double-blind, placebo-controlled clinical trial testing RGN-352, an injectable formulation of Tβ4 for potential use in treating acute myocardial infarction patients (AMI or heart attack). The trial included four groups of ten subjects each to assess the safety and tolerability of escalating doses of RGN-352 injected daily into the blood stream over a 14-day period. To date, RGN-352 appears safe and well-tolerated. There have been no serious drug-related adverse events. A final analysis and report will be submitted to the U.S. Food and Drug Administration in approximately 180 days.

Previously, RegeneRx completed its Phase IA trial in which a single dose of RGN-352, escalating over increasing concentrations, was deemed to be safe and well-tolerated.

"Completing enrollment and dosing of the final part of our Phase I trial is a very important milestone. Although we will submit a final report in six months, thus far RGN-352 appears to be safe and well-tolerated at all doses studied. Based on these data we are prepared to concentrate on our Phase II cardiovascular program and how best to implement a study whose objective is to prevent and repair damage to the heart after a heart attack. Other potential uses of RGN-352 in conditions where short-term systemic administration of the drug candidate may be warranted will also be evaluated," stated David Crockford, RegeneRx's vice president for clinical and regulatory affairs.

About RegeneRx Biopharmaceuticals, Inc.

RegeneRx is focused on the discovery and development of novel peptides to accelerate tissue and organ repair. Currently, RegeneRx is developing three product candidates, RGN-137, RGN-259 and RGN-352 for dermal, ophthalmic, and cardiovascular tissue repair, respectively. These product candidates are based on Tβ4, a 43-amino acid, naturally occurring peptide, in part, under an exclusive world-wide license from the National Institutes of Health. RegeneRx holds over 60 world-wide patents and patent applications related to novel peptides and is currently sponsoring multiple clinical trials in dermal and ophthalmic wound healing and cardioprotection.

RegeneRx Technology Background

Tβ4 is a synthetic version of a naturally occurring peptide present in virtually all human cells. It is a first-in-class multi-faceted molecule that promotes endothelial cell differentiation, angiogenesis in dermal tissues, keratinocyte migration, collagen deposition, and down-regulates inflammation. RegeneRx has identified several molecular variations of Tβ4 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 Tβ4's in vitro and in vivo efficacy in accelerating wound healing and tissue protection under a variety of conditions. Key publications related to Tβ4's cardio-protective effects have been published in Nature and Circulation. Abstracts of these and other scientific papers related to Tβ4's mechanisms of action may be viewed at RegeneRx's web page: www.regenerx.com.

Forward-Looking Statements

This presentation contains certain forward-looking statements that involve risks and uncertainties that could cause actual results to be materially different from historical results or from any future results expressed or implied by such forward-looking statements. Examples of such forward-looking statements include statements concerning the safety and efficacy of RGN-352, target dates for completing the company's ongoing preclinical studies and clinical trials for dermal, ophthalmic, cardiovascular, neurovascular and orphan indications, the potential size of addressable markets, including the market for topical gels, sterile eye drops and parenteral delivery products, the company's ability to enter into any collaborations with respect to the development or commercialization of its product candidates, and the therapeutic potential of Tβ4 for dermal, ophthalmic, cardiovascular and neurovascular wounds. Factors that may cause actual results to differ materially from any future results expressed or implied by any forward-looking statements include the risk that although Tβ4 has demonstrated potential therapeutic benefit for dermal, ophthalmic, cardiovascular and neurovascular wounds, the company's product candidates may not demonstrate safety and/or efficacy in clinical trials, the risk that encouraging results from early research, preclinical studies, compassionate use or clinical trials may not be confirmed upon further analysis of the detailed results of such research, preclinical study, compassionate use or clinical trial, the risk that additional information relating to the safety, efficacy or tolerability of our product candidates may be discovered upon further analysis of preclinical or clinical trial data, the risk that the company's or its collaborators will not obtain approval to market the company's product candidates in the U.S. or abroad, the risks associated with reliance on outside financing to meet capital requirements, the risks associated with reliance on collaborators for the funding or conduct of further development and commercialization activities relating to the company's product candidates, the risks associated with protecting the company's intellectual property, including the risk that the company will not be able to obtain patent protection or that its issued patents will be infringed, and such other risks described in the company's annual report on Form 10-K, for the year ended December 31, 2007, as amended, its quarterly report on Form 10-Q for the period ended March 31, 2008, and other filings the company makes with the SEC. Any forward-looking statements are made pursuant to Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, and, as such, speak only as of the date made. The Company undertakes no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise.