NEW YORK--(BUSINESS WIRE)--SIGA Technologies, Inc. (NASDAQ: SIGA) announced today that the Office of Orphan Products Development (OOPD) of the United States Food and Drug Administration (FDA) has granted Orphan Drug designation to SIGA-246, SIGA’s smallpox drug, for the prevention and treatment of smallpox. In December 2005, the FDA awarded SIGA-246 fast track status to expedite the drug’s review.