Rexahn Pharmaceuticals Initiates Phase II Trial for Zoraxel(TM) to Treat Erectile Dysfunction

ROCKVILLE, Md.--(BUSINESS WIRE)--

Rexahn Pharmaceuticals, Inc. (AMEX:RNN), a biopharmaceutical company dedicated to the discovery, development, and commercialization of innovative treatments for cancer, central nervous system disorders, sexual dysfunction and other unmet medical needs, announced today that the Company has initiated a Phase II clinical trial for its lead clinical compound Zoraxel(TM), for the treatment of Erectile Dysfunction (ED). Zoraxel(TM) is being developed as an orally administered, on-demand-use tablet.

Zoraxel(TM) Phase II trial is a double-blind, placebo-controlled study. This multi-center trial is expected to be complete by the end of 2008.

Commenting on today's news, Dr. Chang H. Ahn, Chairman and Chief Executive Officer of Rexahn, noted, "We are very pleased to announce the initiation of another Phase II trial. Zoraxel(TM) will prove itself a more effective, less toxic therapy for patients with erectile dysfunction."

About Zoraxel(TM)

Zoraxel(TM) is being developed as an immediate release tablet and has a well-established and excellent safety profile, different from current market leading PDE-5 inhibitors with many side effects (priapism, severe hypotension, myocardial infarction, sudden death, increased intraocular pressure and sudden hearing loss). Zoraxel(TM) is a dual neurotransmitter enhancer in the brain, and thus, acts through the central nervous system that regulates sexual functions, whereas the PDE-5 inhibitors work in the peripheral blood vessels and affect only erectile function. In the model studies, Zoraxel(TM) has been shown to significantly improve all three functions of sexual activity, i.e. sexual arousal, erection, and release. As such, Zoraxel(TM) may be a more effective ED treatment for patients who are both responsive and 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. It is estimated to affect 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. Clinical management of ED has progressed substantially in recent years. The advancement of phosphodiesterase-5 (PDE-5) inhibitor therapeutics quickly followed the scientific understanding of the nitric oxide (NO) signaling mechanism in erectile tissue. Adverse events affecting the vascular system have been a major concern with drugs that regulate that response. Investigations into the neurotransmission involved in penile erection, hormone actions involved in this response, and biochemical signal transduction processes within the erectile tissue, are indicative of significant areas of scientific pursuit.

About Rexahn Pharmaceuticals, Inc.

Rexahn Pharmaceuticals is a biopharmaceutical company leveraging its proprietary technology platform to discover, develop and commercialize innovative treatments for cancer, central nervous system disorders, sexual dysfunction and other unmet medical needs. Rexahn's compounds are designed to uniquely treat various disease states while significantly minimizing side effects in order to allow patients to regain their quality of life. For Additional information about Rexahn visit www.rexahn.com

Safe Harbor

This press release contains statements (including projections and business trends) that are forward-looking statements. Rexahn's actual results may differ materially from the anticipated results and expectations expressed in these forward-looking statements as a result of certain risks and uncertainties, including, Rexahn's lack of profitability, its auditor's going concern qualification 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. These forward-looking statements are made as of the date hereof; Rexahn assumes no obligation to update these forward-looking statements.

Source: Rexahn Pharmaceuticals, Inc.

Released June 2, 2008