Rexahn Reports Positive Preliminary Findings in ZoraxelTM Clinical Trial to Treat Erectile Dysfunction

ROCKVILLE, Md.--(BUSINESS WIRE)-- Rexahn Pharmaceuticals, Inc. (NYSE Amex: RNN) today announced preliminary results for its sexual dysfunction drug candidate, Zoraxel(TM), from a Phase IIa clinical study for the treatment of erectile dysfunction (ED). The double blind, randomized, placebo-controlled, dose ranging study found that human subjects treated with Zoraxel demonstrated improved erectile function as measured by changes over the International Index of Erectile Function (IIEF) baseline score within the 8-week treatment period.

The study, which was designed to assess Zoraxel's safety and preliminary efficacy in male subjects ages 18 to 65 with ED, demonstrated a dose dependent treatment effect achieved by Zoraxel as assessed by the IIEF survey. Zoraxel was found to be safe and well tolerated, with no serious adverse events reported. Furthermore, subjects treated with Zoraxel demonstrated improved erectile function and significant improvement in the quality of life measures. Planning is underway for the Phase IIb trial, which will include the Sexual Encounter Profile (SEP) survey, IIEF and quality of life study endpoints.

Commenting on Zoraxel's preliminary results, Dr. Myron Murdock, one of the study investigators and a nationally recognized urologist with expertise in the field of impotence and male-female sexual dysfunction, said, "ED is a condition that affects up to 30 million men in the United States. Based upon the Phase IIa preliminary results, Zoraxel clearly has the potential to be a safer and more effective alternative to currently marketed drugs for ED."

Rexahn Chief Executive Officer, Chang Ahn, PhD, added, "These clinical study results are very encouraging, and substantiate our position that the future of ED treatment lies in compounds that act on the brain (central nervous system) and address the underlying condition. This is a departure from the current standard of care, PDE-5 inhibitors, which only target end organ erectile function. We believe that Zoraxel has the potential to establish a new standard of care for sexual dysfunction."

About Zoraxel^TM

Zoraxel is being developed as an orally administered tablet for on-demand use, and is one of three compounds being developed by Rexahn as a part of the Company's drug pipeline. Zoraxel^TM has a well established and excellent safety record in humans and appears to lack severe side effects associated with standard of care phosphodiesterase (PDE-5) inhibitor ED drugs, such as priapism, severe hypotension, myocardial infarction, sudden death, increased intraocular pressure and sudden hearing loss. Zoraxel^TM is a centrally acting, dual enhancer of neurotransmitters in the brain, whereas PDE-5 inhibitors only target end organ erectile function, and work in peripheral blood vessels. In preclinical animal models, Zoraxel^TM has significantly improved all three functions of sexual activity, i.e. sexual arousal, erection, and release, and may be a more effective ED treatment for patients who are responsive or unresponsive to PDE-5 inhibitors.

About Erectile Dysfunction (ED)

ED is defined as the consistent inability to attain and maintain an erection sufficient for satisfactory sexual intercourse. ED affects up to 30 million men in the United States, with 52% of men between the ages of 40 and 70 reporting difficulty with erectile function. By the year 2025, it is estimated that 322 million men worldwide will suffer from some degree of sexual dysfunction.

About Rexahn Pharmaceuticals, Inc.

Rexahn Pharmaceuticals is a clinical stage pharmaceutical company dedicated to commercializing first in class and market leading therapeutics for cancer, CNS disorders, sexual dysfunction and other unmet medical needs. For more information please visit www.rexahn.com

Safe Harbor

This press release contains forward-looking statements. Rexahn's actual results may differ materially from anticipated results, and expectations expressed in these forward-looking statements, as a result of certain risks and uncertainties, including Rexahn's lack of profitability, and the need for additional capital to operate its business to develop its product candidates; the risk that Rexahn's development efforts relating to its product candidates may not be successful; the possibility of being unable to obtain regulatory approval of Rexahn's product candidates; the risk that the results of clinical trials may not be completed on time or support Rexahn's claims; demand for and market acceptance of Rexahn's drug candidates; Rexahn's reliance on third party researchers and manufacturers to develop its product candidates; Rexahn's ability to develop and obtain protection of its intellectual property; and other risk factors set forth from time to time in our filings with the Securities and Exchange Commission. Rexahn assumes no obligation to update these forward-looking statements.

    Source: Rexahn Pharmaceuticals, Inc.

Released May 4, 2009