Promising Clinical Data with RegeneRx’s Tβ4 Drug Candidates Presented on Second Day of Thymosin Meeting

REGENERX BIOPHARMACEUTICALS, INC. (NYSE Amex:RGN) (www.regenerx.com) today reported on several clinical studies with Thymosin beta 4 (Tβ4) presented the Second International Symposium on Thymosins in Health and Disease, in Catania, Italy. The following are synopses of the presentations:

Myocardial Development of RGN-352 (Injectable Tβ4 Peptide)

David Crockford, RegeneRx’s vice president for clinical and regulatory affairs presented an overview of the biological properties that support Tβ4’s near term and long term clinical applications. Mr. Crockford noted that special emphasis is being placed on the development of RGN-352 for the systemic (injectable) treatment of patients with ST-elevation myocardial infarction (STEMI) in combination with percutaneous coronary intervention, the current standard of care in most western countries for this common type of heart attack. The goal with RGN-352 is to prevent or repair continued damage to cardiac tissue post-heart attack, when such tissue around the damaged site remains at risk.

Dr. Dennis Ruff, vice president and medical director of ICON, and principal investigator, presented the most current results on the Phase I safety study with RGN-352 entitled, “A Randomized, Double-blind, Placebo-controlled, Dose-response Phase I Study of the Safety and Tolerability of the Intravenous Administration of Thymosin Beta 4 and its Pharmacokinetics After Single and Multiple Doses in Healthy Volunteers.” Dr. Ruff discussed key aspects of the study and concluded with, “There were no dose limiting or serious adverse events throughout the dosing period. Synthetic Tβ4 administered intravenously up to 1260 mg, and for up to 14 days, appears to be well tolerated with low incidence of adverse events and no evidence of serious adverse events.”

Ophthalmic Development of RGN-259 (Sterile Tβ4 Eye Drop)

Dr. Steven Dunn, a corneal specialist at Detroit Medical Center, and his colleagues, presented encouraging wound-healing data from a compassionate use clinical trial evaluating the efficacy of RGN-259 (sterile Tβ4 eye drops) in the management of chronic non-healing corneal ulcers caused by the herpes zoster virus. He reported on four patients who ranged in age from 47-84, all of whom had non-healing ulcers of six weeks or longer. The patients were monitored for ulcer size, depth, associated vascularization and comfort during a 28 day treatment period and for 30 days thereafter. “All ulcers (from 0.05 to 12.6 mm²) showed a significant reduction in size during the 28 day treatment period with two ulcers being healed completely at 58 days and the remaining measuring 0.3 mm² and 0.1 mm². No progressive stromal thinning was seen and there was reduced associated ocular irritation,” according to Dr. Dunn.

Dermal Wound Healing with RGN-137 (Topical Tβ4 Peptide)

Dr. G. Guarnera, Department of Vascular Surgery and Pathology, Instituto Dermopatico dell’Immacolata, Rome, Italy, reported on, “The Effect of Thymosin Beta 4 Treatment of Venous Stasis Ulcers (Answers from a Well-Controlled European Clinical Trial).” Dr. Guarnera described the Phase II, 73 patient dose-finding trial that was conducted at eight hospitals in Italy and Poland. He reported that all doses of Tβ4 were well-tolerated with adverse events distributed evenly over the placebo and active treatment groups. In evaluating incidence of healing at day 84 (last study day) and time to healing, the mid-dose Tβ4 group had a 33.3 percent response rate compared to 23.5 percent in the placebo group, and the mid-dose Tβ4 group decreased the median time to healing by 45 percent among all groups. It was reported that the incidence of healing among all groups was shown to decrease with the increase of baseline ulcer area and a longer healing time was associated with larger lesions. “Efficacy findings from this Phase II study suggest that a Tβ4 dose of 0.03 percent may have the potential to accelerate wound healing and that complete wound healing can be achieved within 3 months in about 25 percent of the patients, especially among those whose wounds are small to moderate in size or severity,” according to Dr. Guarnera.

Dr. Jo-David Fine, Professor of Medicine and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, provided an update on a Phase II clinical trial of topically administered RGN-137 for wound healing in inherited epidermolysis bullosa (EB). Dr. Fine reviewed the study parameters and enrollment, which remains blinded to both patients and investigators. He highlighted a notable experience with one enrollee that he personally treated as follows:

“This was in a young woman with severe generalized recessive, dystrophic EB who had been followed by our group for nearly 25 years. Prior to enrollment in this study, her skin wounds invariably took months to even partially heal. Within less than two weeks of initiation of therapy in our study, the test site (her treated wound) completely re-epithelialized (as opposed to other non-treated areas) and did not subsequently break down, as has been the case with other skin wounds arising in this patient. …her remarkably surprising experience gives encouragement to the potential clinical value of this agent, when applied topically, in patients with inherited EB,” remarked Dr. Fine.

“Today’s clinical presentations were informative and provide encouraging follow-up to previous clinical reports. We heard about an EB patient (with a 25% chance of receiving placebo) where healing was completely different, i.e., quicker and more durable, than had been the case for the past 25 years according to her physician. This healing and scarring process appears similar to published and unpublished reports of the regulation of scarring in the heart, kidney, liver, and skin by Tβ4 and its derivatives,” stated J.J. Finkelstein, RegeneRx’s president and chief executive officer. He continued, “Dr. Guarnera’s data in the venous stasis trial were also important as they suggest that RGN-137 could potentially be useful to accelerate wound healing in patients with less severe or smaller venous stasis ulcers. Finally, the improved wound healing in neurotrophic corneal ulcer patients, reported by Dr. Dunn, is consistent with previously published animal studies showing accelerated wound healing in the eye. It is important to note that, to date, in all clinical studies with RegeneRx’s drug candidates, Tβ4 was found to be safe and well tolerated.”

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. RegeneRx is also developing RGN-457 for use in pulmonary indications such as cystic fibrosis. These product candidates are based on Tβ4, a synthetic copy of 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. It is currently sponsoring Phase II clinical trials for dermal and ophthalmic wound healing and recently completed a Phase I clinical trial supporting systemic delivery of RGN-352 for acute cardiovascular indications. RegeneRx is also developing novel peptides for the cosmeceutical industry based on its experience with Tβ4 and its biological activities in the skin.

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. Abstracts of scientific papers related to Tβ4’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, and RGN-457. Clinical results and/or commercial benefit may differ materially from those described in presentations by researchers at the Thymosin meeting, some of whom collaborate with RegeneRx. 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, 2008 and such other items described in the filed Company’s quarterly report on Form 10-Q for the fiscal quarter ended June 30, 2009 or 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.