ROCKVILLE, Md.--(BUSINESS WIRE)--Rexahn Pharmaceuticals, Inc. (NYSE Amex: RNN), a clinical stage pharmaceutical company commercializing potential best in class oncology and CNS therapeutics, today announced that it has enrolled the first subject in its exploratory Phase I clinical trial of RX-3117 in cancer patients. The study is conducted in Europe and it is aiming at assessment of oral bioavailability of RX-3117 in humans. Subject enrollment will continue through the first half of 2012, with preliminary data expected in second half of 2012.