ROCKVILLE, Md.–(BUSINESS WIRE)–
Rexahn Pharmaceuticals, Inc. (NYSE MKT:RNN) a clinical stage biopharmaceutical company developing best-in-class therapeutics for the treatment of cancer, today announced additional data from preclinical studies on the anti-tumor effects of RX-3117, a next generation cancer cell specific nucleoside analog. In the study, oral administration of RX-3117 inhibited tumor growth in 12 different human cancer xenograft models including colon, non-small cell lung, small cell lung, pancreatic, renal, ovarian, and cervical cancer. In addition, RX-3117 inhibited the growth of human cancer cells lines shown to be resistant to the anti-cancer effects of gemcitabine, including in the primary low-passage human pancreatic tumorgraft model.
“Resistance to the anti-cancer effects of gemcitabine represents a major clinical issue in the treatment of cancer patients. Up to 25% of cancer patients receiving one or more cycles of gemcitabine rapidly become resistant to its anti-cancer activity. Based on study results to date, both preclinical and clinical, we believe RX-3117 holds the potential to be used for the treatment of tumors that do not respond to gemcitabine and other chemotherapeutic drugs,” commented Rexahn’s CEO, Peter D. Suzdak, Ph.D.
RX-3117 showed greater efficacy (tumor growth inhibition) as compared to gemcitabine in four different xenograft animal models with gemcitabine resistant human cancer cell lines: colorectal cancer (Colo205), small cell lung cancer (H69), cervical cancer (CaSki) and pancreatic cancer (CTG-0298).
Additionally, in a mouse xenograft model using human colorectal cancer cells, those treated with RX-3117 showed significantly longer survival as compared to those receiving other treatments. Mice treated with RX-3117 showed 100% survival through day 95 after initial treatment, compared to 13% of mice treated with gemcitabine, and 25% of mice treated with irinotecan, both FDA-approved drugs.
Results of these studies were presented in a poster titled, “A novel small molecule cytidine analog, RX-3117, shows potent efficacy in xenograft models, even in tumors that are resistant to treatment with gemcitabine,” at the American Association for Cancer Research (AACR) Annual Meeting 2014 on April 6, 2014.
Earlier this year, Rexahn initiated a Phase Ib trial for RX-3117. The trial is a multi-center dose-escalation study which is evaluating the safety, tolerability, dose-limiting toxicities and maximal tolerated dose (MTD) of RX-3117 in patients with solid tumors. Secondary endpoints include characterizing the pharmacokinetic profile of RX-3117 and evaluating the preliminary anti-tumor effects of RX-3117.
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.
