October 1, 2008

RegeneRx to Develop RGN-457 for Cystic Fibrosis

REGENERX BIOPHARMACEUTICALS, INC. (AMEX:RGN) (www.regenerx.com) announced today that it is seeking a strategic partner to assist in the development of RGN-457 for the treatment of cystic fibrosis (CF). RGN-457 is based on thymosin beta 4 (TB4) peptide formulated as an inhaled therapeutic agent to address this patient population. CF is a life-threatening, hereditary disease that impairs the patient's ability to breathe due to the accumulation of thick and sticky mucus secretions in the airways of the lungs. There are estimated to be 30,000 and 40,000 CF patients in the U.S. and Europe, respectively. It is, therefore, considered an "orphan" disease in both territories. In 2006, the predicted median age of survival for patients with cystic fibrosis was 37 years.

"Having been involved in cystic fibrosis research and the development of several of the CF therapies currently on the market, I believe RGN-457 has the potential to be an important treatment for CF. Our published data indicating that TB4 reduces the cohesivity of CF sputum, and data from others showing TB4's anti-inflammatory properties, strongly suggest that RGN-457 could be a novel and important pulmonary therapy for persons with CF," stated Bruce Rubin, M.D., M.Engr., M.B.A., Professor and Vice Chair of Pediatrics, Wake Forest University, Winston-Salem, NC.

"We have completed a substantial amount of preclinical work necessary for an IND application, in addition to existing toxicology and pharmacokinetic data from our current clinical programs. We believe RGN-457 could be developed relatively quickly with appropriate resources, thus, our interest is in identifying a strong strategic partner to work with us on this important product opportunity," stated J.J. Finkelstein, RegeneRx's president & chief executive officer.

About Cystic Fibrosis

Cystic fibrosis is an inherited chronic disease that affects the lungs and digestive system of more than 30,000 children and adults in the United States (70,000 worldwide). A defective gene and its protein product cause the body to produce unusually tenacious mucus that clogs the lungs and leads to life-threatening lung infections. People with CF can have salty-tasting skin; frequent coughing and sputum; persistent lung infections; shortness of breath; poor growth/weight gain; and greasy, bulky stools or difficulty in bowel movements. About 1,000 new cases of cystic fibrosis are diagnosed each year. More than 70% of patients are diagnosed by age two. More than 40% of the CF patient population is age 18 or older. In 2006, the predicted median age of survival was 37 years.

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. The Company is also developing RGN-457 for use in pulmonary indications such as cystic fibrosis. These product candidates are based on TB4, 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 three Phase II chronic dermal wound healing clinical trials, a Phase II ophthalmic wound healing clinical trial, and a Phase I parenteral (injectable) clinical trial supporting systemic delivery of RGN-352 for acute cardiovascular indications.

About Thymosin beta 4 (TB4)

TB4 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 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 TB4's in vitro and in vivo efficacy in accelerating wound healing and tissue protection under a variety of conditions. Key publications related to TB4's cardio-protective effects have been published in Nature and Circulation. Abstracts of these and other scientific papers related to TB4's mechanisms of action may be viewed at RegeneRx's web page: www.regenerx.com.

Forward-Looking Statements

Any statements in this press release that are not historical facts are forward-looking statements made under the provisions of The Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the words "project,""believe,""anticipate,""plan,""expect,""estimate,""intend,""should,""would,""could,""will,""may" or other similar expressions and include statements regarding the safety and efficacy of RGN-137, RGN-259, RGN-352, RGN-457 and the status and prospects of any ongoing pre-clinical studies related to RGN-457. Actual results may differ materially from those indicated or implied by such forward-looking statements because the Company's product candidates may not demonstrate safety and/or efficacy in current or future clinical trials or as a result of various important factors described in the Company's filings with the Securities and Exchange Commission ("SEC"), including those identified in the "Risk Factors" sections of the annual report on Form 10-K for the year ended December 31, 2007 filed with the SEC on March 28, 2008 and other periodic reports filed with the SEC. Any forward-looking statements in this press release represent the Company's views only as of the date of this release and should not be relied upon as representing its views as of any subsequent date. The Company anticipates that subsequent events and developments may cause its views to change, and the Company specifically disclaims any obligation to update this information, as a result of future events or otherwise, except as required by applicable law.