Rexahn Pharmaceuticals Announces the Publication of Preclinical Data for Supinoxin(TM) (RX-5902) Demonstrating Mechanism of Action

ROCKVILLE Md., Feb. 9, 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 announced the release of an online publication describing preclinical results for Supinoxin™ (RX-5902) in the peer reviewed medical journal, Journal of Cellular Biochemistry, in an article titled, "A Novel Anti-Cancer Agent, 1-(3,5-Dimethoxyphenyl)-4-[(6-fluoro-2-methoxyquinoxalin-3-yl)aminocarbonyl] piperazine (RX-5902), Interferes with β-Catenin Function through Y593 phospho-p68 RNA Helicase." The article was coauthored by Dr. Zhi-Ren Liu of the Department of Biology, at Georgia State University, and Rexahn scientists.

In this study, Supinoxin was shown to directly bind to phosphorylated p68 and inhibit β-catenin dependent ATPase activity resulting in a decrease in expression of a number of cancer related downstream genes (oncogenes) such as c-Myc, cyclin-D1 and p-cJun. The expression of these oncogenes is a key step in the growth and proliferation of cancer cells. The ability of Supinoxin to disrupt the β-catenin/phosphorylated p68/oncogene pathway represents a novel mechanism for the inhibition of growth of human cancer cells.

Dr. Zhi-Ren Liu of the Department of Biology, Georgia State University and coauthor of this study, commented, "The ability of Supinoxin to directly bind to P-p68 and abolish the effects of P-p68 in upregulation of these oncogenes is very exciting. This novel pathway holds great promise for treatment of cancer patients."

Peter D. Suzdak, Ph.D., Rexahn's Chief Executive Officer, commented, "The specificity of this mechanism of action for cancer cells and the efficacy seen in multiple preclinical models utilizing human cancer cells continues to generate significant interest in Supinoxin. Once the current Phase I clinical trial is complete, we will provide an update on the safety, tolerability, dose-limiting toxicities, maximal tolerated dose (MTD), pharmacokinetics and preliminary anti-tumor effects seen with Supinoxin."

About Supinoxin™ (RX-5902)

Supinoxin™ (RX-5902) is an orally administered, potential first-in-class, small molecule inhibitor of phosphorylated-p68 (P-p68). P-p68, which is selectively expressed in cancer cells and is absent in normal tissue, increases the activity of multiple cancer related genes including cyclin D1, c-jun and c-myc, and plays a role in tumor progression and metastasis. Over-expression of phosphorylated-p68 has been observed in solid tumors, such as melanoma, colon, ovarian and lung tumors. In preclinical studies, Supinoxin has been shown to inhibit proliferation of cells in 18 human cancer cell lines including breast, colon, pancreas, ovarian, and stomach cancers, and showed potent activity in drug-resistant cancer cells. In preclinical animal models, where human cancer cells from melanoma, pancreas, renal or ovarian tumors were grafted into animals, treatment with Supinoxin resulted in a significant reduction in tumor growth.

The Phase I trial of Supinoxin is a dose-escalation study designed to evaluate the safety, tolerability, dose-limiting toxicities and maximal tolerated dose (MTD) in patients with solid cancer tumors that have previously failed treatment with approved therapies. Secondary endpoints include pharmacokinetic analysis and evaluating the preliminary anti-tumor effects of Supinoxin. This trial is being conducted at three clinical oncology centers in the United States. Each patient has the ability to continue on the drug up to six cycles of treatment (a dosing cycle is defined as three weeks of drug treatment followed by one week off) if no disease progression is seen. Patients are assessed by CT or MRI prior to the start of therapy and after every two cycles of therapy to assess tumor progression. The decision to escalate dose is made after completion of one cycle of treatment based on safety and tolerability. Patients have the possibility to receive up to six cycles of treatment if there is no disease progression. Tumor biopsy samples are taken to assess the biomarker phosphorylated-p68. Patient enrollment has been completed in five dose groups (25, 50, 100, 150 and 225 mg) and patients are now enrolling for the sixth dose group (300 mg). The MTD of Supinoxin has not yet been achieved. In preliminary pharmacokinetic data, Supinoxin has approximately 51% oral bioavailability. The ongoing Phase I clinical trial is expected to be completed in the first half of 2015.

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 SupinoxinTM (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

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 Tricia Truehart (646) 378-2953

Source:Rexahn Pharmaceuticals