April 17, 2003

News Release: First Subjects Enrolled in RegeneRx's Phase I Clinical Trial; Thymosin beta 4 Enters Human Testing for Chronic Dermal Wounds

RegeneRx Biopharmaceuticals, Inc. (OTCBB:RGRX), whose primary focus is on drugs to treat acute and chronic wounds, announced today the enrollment of the first human subjects in clinical trials to test Thymosin beta 4 (TB4).

The clinical trials will be conducted in New Orleans, Louisiana. Pursuant to U.S. Food and Drug Administration regulations, the trials will utilize several dosages of the drug administered to healthy individuals to ensure that it can be safely tolerated in larger patient populations. Dr. Allan L. Goldstein, founder of RegeneRx and Chairman of Biochemistry and Molecular Biology at The George Washington University Medical School in Washington, DC, stated, 'This is an exciting moment in the history of RegeneRx as the initiation of human clinical trials is a very important milestone in the development of our novel wound healing drug. Since TB4 occurs naturally in humans and we've seen no adverse toxicity in animal studies, we expect the same results in humans.'

According to J.J. Finkelstein, President and CEO of RegeneRx, 'We have worked very hard to build the company utilizing a business model that requires minimal infrastructure, yet allows for effective development of our proprietary technology platform. While the clinical trial process is arduous, we believe the study of TB4 may move more rapidly and be less costly than the development of many other types of drugs, such as certain anti-cancer drugs, as the clinical endpoints are measured in months rather than years. Thus, we are highly focused in our effort to establish the efficacy of TB4 for chronic dermal wounds as well as for other related clinical indications.'

TB4 is a naturally occurring 43-amino acid peptide whose gene is up regulated following tissue injury and during the remodeling and differentiation of cells.

TB4 represents a new class of wound healing compound and is different from other wound repair factors, such as growth factors, in that it promotes endothelial and keratinocyte cell migration, down regulates a number of inflammatory cytokines and chemokines, and has a very low molecular weight, allowing it to diffuse relatively long distances through tissues.

One of its key mechanisms of action is TB4's ability to regulate the cell-building protein, actin, a vital component of the cytoskeleton.

It has been the subject of a significant amount of research at the National Institutes of Health (NIH) and other academic institutions, having been reported to effectively repair dermal and corneal wounds in numerous animal models under a variety of conditions. Further, it has been delivered both topically and systemically with both routes of administration showing similar activity for dermal wounds.

The fact that TB4 is active across a broad spectrum of wounds with various underlying causes would indicate that it is a necessary component of the wound repair process.

About RegeneRx

RegeneRx Biopharmaceuticals, Inc. is developing TB4 for the treatment of acute and chronic wounds and for the treatment of a variety of human diseases involving tissue and organ repair under an exclusive worldwide license from the NIH.

The Company holds several patents related to the technology and has numerous worldwide patent applications pending and will explore other medical markets where TB4 may prove effective by using strategic partners for product development and intends to evaluate novel compounds that complement its core expertise. Additional information is available at the RegeneRx Web site at http://www.regenerx.com

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 and commercialization 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 contained in this press release 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.

RegeneRx Biopharmaceuticals, Inc. Media Contacts: Lori Smith, 301/961-1992 This email address is being protected from spambots. You need JavaScript enabled to view it. or The Ruth Group Gregory Tiberend, 646/536-7005 This email address is being protected from spambots. You need JavaScript enabled to view it.

WEBSITE This email address is being protected from spambots. You need JavaScript enabled to view it.