Rexahn Achieves 50% Enrollment Milestone in Serdaxin(TM) Phase IIa Clinical Trial for Depression

ATLANTA--(BUSINESS WIRE)-- Rexahn Pharmaceuticals, Inc. (NYSE Amex: RNN), today announced that it has enrolled 50% of the total projected enrollment required for its Phase IIa trial to evaluate the safety and preliminary efficacy of Serdaxin(TM) as a central nervous system based treatment for Major Depressive Disorder (MDD). The complete trial calls for the enrollment of up to 80 patients at multiple clinical trial sites in the United States.

"This patient enrollment milestone in the Serdaxin clinical trial is an exciting step forward. We anticipate that enrollment will continue to move quickly, and preliminary study results may be available by year end. Serdaxin is of particular importance in meeting unmet needs in depression, because it appears to have fast onset of action in animal models and lacks the serious side effects associated with existing antidepressant drugs, including nausea, vomiting, insomnia, weight gain and sexual dysfunction." Said Dr. Chang Ahn, CEO of Rexahn

The Serdaxin Phase IIa clinical trial is designed as a randomized, double blind, placebo controlled and dose ranging study. Main endpoints include clinically validated depression rating scales, and quality of life surveys. The Serdaxin Phase IIa study in MDD was initiated February 2009, and the Company anticipates completion of enrollment by July 2009.

Rexahn will be presenting at the BIO 2009 International Convention at the Georgia World Congress Center (Room 314, Building A, Level 3) in Atlanta, GA on Wednesday, May 20, 2009 at 3:00 PM ET.

About Serdaxin^TM

Serdaxin^TM is a potential market leading CNS neuroprotective agent and antidepressant. Among lead indications, we are investigating Serdaxin for depression in Phase II clinical trials. Serdaxin may achieve greater and broader therapeutic coverage, and appears to have no serious side effects such as nausea, vomiting, insomnia, weight gain, sexual dysfunction, cognitive deficit or motor impairment that are linked to existing antidepressant drugs. Serdaxin has well-established and excellent human safety. In preclinical studies, Serdaxin had onset of action in less than two days. Based on its novel mechanism as a dual serotonin and dopamine enhancer, it is a potential treatment for multiple CNS disorders where these neurotransmitters are depleted or implicated in CNS-based illnesses, such as Parkinson's disease (PD). Serdaxin has the potential to address both non-motor and motor events of PD by serving as a neuroprotective agent and addressing loss of dopaminergic neurons that lead to loss of control of movements; and further, enhancing serotonin and dopamine levels that are involved in depression and mood disorders. Rexahn has multiple clinical programs planned for Serdaxin including depression and anxiety disorders, Parkinson's disease, Alzheimer's and neurodegenerative illnesses, neuroprotection and biodefense uses.

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 18, 2009