ROCKVILLE, Md.--(BUSINESS WIRE)--Rexahn Pharmaceuticals, Inc. (NYSE MKT: RNN), a clinical stage biopharmaceutical company developing potential best-in-class oncology therapies, today announced that it will present mechanism of action data on RX-5902 during a poster session at the American Association for Cancer Research (AACR) 104th Annual Meeting being held in Washington, DC, April 6-10, 2013, at the Washington Convention Center.