RegeneRx Biopharmaceuticals, Inc. (OTC Bulletin Board: RGRX) ("the Company" or "RegeneRx") today announced positive new data related to RGN-259, its preservative-free ophthalmic drug candidate. In a second "dry eye" study conducted by Ora, Inc. using their Preclinical CAE? Murine (mouse) Model, four active concentrations of RGN-259 were compared to three control groups, consisting of a negative control (vehicle) and two positive controls (doxycycline and Restasis?). The animals were treated for a total period of nine days following the inducement of moderate, and then severe, dry eye. In the moderate dry eye phase of the study, after six days of treatment, two concentrations of RGN-259 showed a statistically significant reduction in corneal fluorescein staining, a method used to determine the extent of damage to the cornea, which returned to near baseline (normal) levels. After inducement of severe dry eye in the same mice, treatment with RGN-259 for three additional days similarly showed a greater reduction of corneal staining compared to the control groups, although no group achieved statistical significance. This study confirms and expands upon a previous study that also showed a statistically significant reduction of corneal staining back to near baseline levels in a similar animal model. Data from both studies will be presented at the 2011 Association for Research in Vision and Ophthalmology (ARVO) meeting in Ft. Lauderdale on May 3.

"Two different concentrations of RGN-259 were observed to be superior to the positive controls and reduced staining essentially to baseline levels in the standard murine dry eye model. The mechanism of action of wound healing and anti-inflammatory properties of T?4, together with the preclinical data from this and the prior animal study indicate a substantial therapeutic potential in dry eye," stated George Ousler III, vice-president of dry eye at Ora, Inc., Andover, MA.

"The results of this latest animal study will have a significant impact on our clinical program and how we view the path toward development of RGN-259. We believe the two dry eye animal studies, along with previous positive results in humans that showed the ability of RGN-259 to repair non-healing corneal ulcers, with no observed adverse safety events, provide a solid foundation to support commercial development. We have already begun planning a Phase 2 clinical trial focused on developing RGN-259 for the treatment of dry eye," stated J.J. Finkelstein, RegeneRx's president and chief executive officer.

About Dry Eye

According to Global Data, an industry market research firm, the world-wide annual market for dry eye disorders was approximately $1.9 billion in 2010 and is estimated to reach $2.8 billion by 2017. The development of dry eyes can have many causes. They include: (1) age - people over age 65 often experience some symptoms of dry eyes; (2) gender - women are more likely to develop dry eyes due to hormonal changes caused by pregnancy, the use of oral contraceptives, and menopause; (3) medications - certain medicines, including antihistamines, decongestants, blood pressure medications and antidepressants; (4) medical conditions - persons with rheumatoid arthritis, diabetes, thyroid problems, Sjögren's syndrome, and lupus are more likely to have symptoms of dry eyes; (5) blepharitis - inflammation of the surfaces of the eye, or the inward or outward turning of eyelids can cause dry eyes to develop; (6) environmental conditions - exposure to smoke, wind and dry climates can increase tear evaporation resulting in dry eye symptoms; (7) other factors - long term use of contact lenses, and refractive eye surgeries, such as LASIK.

About RegeneRx Biopharmaceuticals, Inc. (www.regenerx.com)

RegeneRx is focused on the development of a novel therapeutic peptide, Thymosin beta 4, or T?4, for tissue and organ protection, repair and regeneration. RegeneRx currently has three drug candidates in clinical development and has an extensive worldwide patent portfolio covering its product candidates.

RGN-259 is a sterile, preservative-free topical eye drop for ophthalmic indications. Based on recent human clinical data, RegeneRx is currently supporting a physician-sponsored Phase 2 dry eye study with RGN-259 and has completed two animal studies showing RGN-259's positive effects on dry eye symptoms. Previously, seven patients with non-healing corneal ulcers were treated with RGN-259 under compassionate use INDs. Five had complete healing and two had substantial healing of their wounds. Three additional patients with corneal defects, called punctate keratitis, had no evidence of healing although they did report reduction in eye inflammation and increased comfort.

RGN-352 is an injectable formulation to treat cardiovascular and central nervous system diseases, as well as other medical indications. RegeneRx has successfully completed a Phase 1 clinical trial with RGN-352 in which the drug candidate was found to be safe and well-tolerated. The Company is conducting a Phase 2 clinical trial at approximately 20 clinical sites in the U.S., Israel, and Russia, although this trial is currently on an FDA-imposed clinical hold. RegeneRx recently received a $3 million, three-year development grant from the NIH to support the company's acute myocardial infarction program.

RGN-137, a topical gel formulation, is currently being evaluated by RegeneRx in a Phase 2 clinical trial for the treatment of the orphan skin disease epidermolysis bullosa. Other potential uses for RGN-137 include the treatment of chronic dermal wounds and reduction of scar tissue.

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. These forward-looking statements include statements concerning the plans for future development and regulatory approval of RGN-259. Forward-looking statements 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. You are urged to consider statements that include the words "estimate," "will," "may," "potential" or the negative of those words or other similar expressions to be uncertain and forward-looking. Factors that may cause actual results to differ materially from any future results expressed or implied by any forward-looking statements include risks related to uncertainties inherent in our business, including, without limitation the risk that our product candidates do not demonstrate safety and/or efficacy in current clinical trials or future non-clinical or clinical trials; risks related to our ability to obtain financing to support our operations on commercially reasonable terms; the progress, timing or success of our clinical trials; difficulties or delays in development, testing, obtaining regulatory approval for producing and marketing our product candidates; regulatory developments; the size and growth potential of the markets for our product candidates and our ability to serve those markets; the scope and validity of patent protection for our product candidates; competition from other pharmaceutical or biotechnology companies; and other risks described in the Company's filings with the Securities and Exchange Commission ("SEC"), including those identified in the "Risk Factors" section of the annual report on Form 10-K for the year ended December 31, 2010, filed with the SEC on March 31, 2011, as well as other filings it makes 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.

For RegeneRx:
Lippert/Heilshorn & Associates, Inc.
Kim Golodetz
212.838.3777
kgolodetz@lhai.com
or
Bruce Voss
310.691.7100
bvoss@lhai.com