Rexahn Pharmaceuticals, Inc. (NYSE Amex: RNN), a clinical stage pharmaceutical company developing and commercializing best in class oncology and CNS therapeutics, today announced the publication of preclinical results for RX-5902 in Bioorganic & Medicinal Chemistry [20:1303-1309, 2012] titled, “Synthesis, anticancer activity and pharmacokinetic analysis of 1-[(substituted 2-alkoxyquinoxalin-3-yl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives.” In the study, various new quinoxalinyl-piperazine derivatives were shown to have excellent anti-proliferative activity against different human cancer cells, and some selected compounds showed excellent pharmacokinetic properties in rats. In particular, RX-5902 exhibited desirable pharmacokinetic properties – such as in oral bioavailability, half-life, and plasma concentration - supporting its continued development as an orally deliverable potent anti-cancer drug. “In this second published study of RX-5902, we further establish that it is a potent anti-cancer compound with the optimal pharmacokinetic properties for oral administration,” said Rick Soni, President of Rexahn. “For RX-5902, as a first-in-class RNA helicase inhibitor, we plan to file an Investigational New Drug application in the second quarter of this year.” In November 2010, Rexahn published additional pre-clinical data in Bioorganic & Medicinal Chemistry [18:7966-7974, 2010], demonstrating that RX-5902, significantly inhibited the growth of human cancer cells, including paclitaxel (Taxol ®) resistant HCT-15 human colorectal cancer cells, and showed potential use in combination therapy with known anticancer drugs such as paclitaxel, doxorubicin, gemcitabine, 5-FU and cisplatin. About RX-5902 RX-5902 is a first-in-class small molecule that binds to and dysregulates p68 RNA helicase. RX-5902 also inhibits G2/M cell cycle progression, which is critical for cell cycle growth and cancer progression, and induces apoptotic cell death in cancer cells. Preclinical studies showed RX-5902 inhibits tumor growth, including drug-resistant tumors, in xenograft models by oral administration. About Rexahn Pharmaceuticals, Inc. Rexahn Pharmaceuticals is a clinical stage pharmaceutical company dedicated to developing and 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 operates key R&D programs of nano-medicines, 3D-GOLD, and TIMES drug discovery platforms. For more information, please visit www.rexahn.com. Safe Harbor To the extent any statements made in this press release deal with information that is not historical, these are forward-looking statements under the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements about Rexahn's plans, objectives, expectations and intentions with respect to future operations and products and other statements identified by words such as "will," "potential," "could," "can," "believe," "intends," "continue," "plans," "expects," "anticipates," "estimates," "may," other words of similar meaning or the use of future dates. Forward-looking statements by their nature address matters that are, to different degrees, uncertain. Uncertainties and risks may cause Rexahn's actual results to be materially different than those expressed in or implied by Rexahn's forward-looking statements. For Rexahn, particular uncertainties and risks include, among others, the difficulty of developing pharmaceutical products, obtaining regulatory and other approvals and achieving market acceptance; the marketing success of Rexahn's licensees or sublicensees; the success of clinical testing; and Rexahn's need for and ability to obtain additional financing. More detailed information on these and additional factors that could affect Rexahn's actual results are described in Rexahn's filings with the Securities and Exchange Commission, including its most recent annual report on Form 10-K and subsequent quarterly reports on Form 10-Q. All forward-looking statements in this news release speak only as of the date of this news release. Rexahn undertakes no obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.