Rexahn Completes Patient Enrollment in Serdaxin(TM) Phase IIa Clinical Trial for Depression

ROCKVILLE, Md.--(BUSINESS WIRE)-- Rexahn Pharmaceuticals, Inc. (NYSE Amex: RNN), a clinical stage biopharmaceutical company developing best in class oncology and CNS therapeutics, today announced that it has completed patient enrollment in its Phase IIa clinical trial evaluating the effectiveness of Serdaxin(TM) as a treatment for major depressive disorder (MDD).

The randomized, double blind, placebo controlled and dose ranging study enrolled 75 patients and is being conducted at multiple sites in the United States. The Serdaxin Phase IIa study in MDD was initiated in February 2009, with preliminary findings anticipated in late 2009. The primary efficacy endpoint of the Serdaxin Phase IIa is the change from baseline on the Montgomery-Asberg Depression Rating Scale (MADRS).

Dr. Chang H. Ahn, Chief Executive Officer of Rexahn commented, "The completion of patient enrollment in the Phase IIa clinical trial moves us closer to bringing Serdaxin to market as quickly as possible. For the many patients suffering from MDD, Serdaxin holds the promise of being an effective treatment without producing the serious side effects commonly associated with currently marketed antidepressant drugs."

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. Rexahn currently has three drug candidates in Phase II clinical trials - Archexin, Serdaxin, and Zoraxel - all potential best in class therapeutics, and a robust pipeline of preclinical compounds to treat multiple cancers and CNS disorders. Rexahn also has key R&D programs in cancer nano-medicines and multi-target aimed ligands drug discovery technologies. 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 July 7, 2009