ROCKVILLE, Md.--(BUSINESS WIRE)--Rexahn Pharmaceuticals, Inc. (OTC BB:RXHN), a biopharmaceutical company dedicated to the discovery, development, and commercialization of innovative treatments for cancer, central nervous system disorders, sexual dysfunction and other unmet medical needs, today announced that the U.S. Patent & Trademark Office has issued to the Company U.S. Patent 7,205,283, entitled “Antisense Oligonucleotides that Inhibit Expression of HIF-1.”