NEW YORK, June 23, 2010 (GLOBE NEWSWIRE) -- SIGA Technologies, Inc. (Nasdaq:SIGA), a company specializing in the development of pharmaceutical agents to combat bio-warfare pathogens, announced today the successful completion of its fourth human clinical trial, supporting the safety and tolerability of the anticipated clinical dose of ST-246®, SIGA’s lead smallpox antiviral drug candidate. Analyses of the trial’s results are consistent with findings from previous studies of ST-246 and together show that the drug will likely be found to be a safe and well-tolerated therapeutic for the treatment of orthopoxvirus infections.