ROCKVILLE, Md., April 20, 2015 (GLOBE NEWSWIRE) -- Rexahn Pharmaceuticals, Inc. (NYSE MKT:RNN), a clinical stage biopharmaceutical company developing best-in-class therapeutics for the treatment of cancer, today presents preclinical data on RX-3117 at the 2015 American Association for Cancer Research (AACR) Annual Meeting in Philadelphia. The presentation is entitled "Fluorocyclopentenylcytosine (RX-3117) is activated by uridine-cytidine kinase 2 (UCK2), a potential biomarker," and is co-authored by Dr. G.J. Peters of the VU University Medical Center, Amsterdam, The Netherlands, and Rexahn scientists.

The present study demonstrates a correlation between the expression and enzymatic activity of UCK2 (the enzyme responsible for activating/phosphorylating RX-3117) and the ability of RX-3117 to inhibit the growth of various human cancer cells. "These data are important because they further confirm RX-3117's cancer cell specific mechanism of action and the study further suggests that UCK2 expression can be used as a potential biomarker for patient selection into RX-3117 clinical trials," commented Rexahn's CEO, Peter D. Suzdak, Ph.D. "Beyond clinical trials, use of a specific biomarker enables Rexahn to offer personalized medicine by identifying which cancer patients may be most responsive to our treatments."

Dr. Peters added, "RX-3117 represents a novel approach to specifically target solid tumors such as gemcitabine resistant pancreatic, lung and bladder cancers. The ability to determine the abundance of UCK2 in a tumor will enhance the design and outcome of the RX-3117 clinical program."

RX-3117 is currently in a Phase Ib clinical trial in cancer patients with solid tumors with clinical data expected in the first half of 2015.

About RX-3117

RX-3117 is a novel small molecule anti-metabolite compound that once activated (phosphorylated) by UCK2 is incorporated into DNA or RNA of cells and inhibits both DNA and RNA synthesis which induces apoptotic cell death of tumor cells. UCK2 is overexpressed in various human cancer cells. RX-3117 also mediates the downregulation of DNA methyltransferase 1 (DNMT1), an enzyme responsible for the methylation of cytosine residues on newly synthesized DNA and also a target for anticancer therapies. Preclinical studies have shown RX-3117 to be effective in both inhibiting the growth of various human cancer xenograft models, including colon, lung, renal and pancreas, as well as gemcitabine resistant cancer cells.

RX-3117 has demonstrated a broad spectrum anti-tumor activity against 50 different human cancer cell lines and efficacy in 12 different mouse xenograft models. The efficacy in the mouse xenograft models was superior to that of gemcitabine. In addition, RX-3117 still retains its full anti-tumor activity in human cancer cell lines made resistant to the anti-tumor effects of gemcitabine. In August 2012, Rexahn reported the completion of an exploratory Phase I clinical trial of RX-3117 in cancer patients conducted in Europe, to investigate the oral bioavailability, safety and tolerability of the compound. In this study, oral administration of RX-3117 demonstrated an oral bioavailability of 56% and a plasma half-life (T1/2) of 14 hours. In addition, RX-3117 was safe and well tolerated in all subjects throughout the dose range tested.

RX-3117 is undergoing a Phase Ib clinical trial in cancer patients with solid tumors. The Phase Ib clinical trial is a multi-center dose-escalation study that will evaluate the safety, tolerability, dose-limiting toxicities and maximal tolerated dose (MTD) of RX-3117 in patients with solid tumors. Secondary endpoints will include characterizing the pharmacokinetic profile of RX-3117 and evaluating the preliminary anti-tumor effects of RX-3117. Patient enrollment has been completed in eight dose groups (30, 60, 100, 150, 200, 500, 1000 and 1500 mg). The MTD of RX-3117 has not yet been achieved. The ongoing Phase I clinical trial is expected to be completed in the first half of 2015 once the MTD has been achieved.

About Rexahn Pharmaceuticals, Inc.

Rexahn Pharmaceuticals is a clinical stage biopharmaceutical company dedicated to developing best-in-class therapeutics for the treatment of cancer. Rexahn currently has three clinical stage oncology candidates, Archexin®, RX-3117 and Supinoxin™ (RX-5902) and a robust pipeline of preclinical compounds to treat multiple types of cancer. Rexahn has also developed proprietary drug discovery platform technologies in the areas of Nano-Polymer-Drug Conjugate Systems (NPDCS), nano-medicines, 3D-GOLD, and TIMES. 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 cash flow requirements, future operations and products, enrollments in clinical trials, the path of clinical trials and development activities, 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 success and design 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.

CONTACT: The Trout Group LLC
         Chad Rubin
         (646) 378-2953
         crubin@troutgroup.com

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