SIGA completes fourth human clinical trial of ST-246 smallpox antiviral drug candidate

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.

The trial was conducted at three sites: Orlando Clinical Research Center (Orlando, FL), Apex Research Institute (Santa Ana, CA) and Hawaii Clinical Research Center (Honolulu, HI). A total of 107 healthy volunteers were enrolled in the study and were randomly placed into one of three different groups, each of which received either 400 or 600 mg of ST-246 or a placebo, once a day, for 14 days. All adverse events reported during the study that were considered related to ST-246 were mild to moderate. There were no severe adverse events.

"We are very satisfied with SIGA's progress in completing the studies needed to demonstrate the safety, bio-availability and efficacy of ST-246," said Dennis E. Hruby, SIGA's Chief Scientific Officer. "In addition to reaffirming the strong safety profile of ST-246, the trial results suggest an appropriate dose that we will use as we complete the remaining New Drug Application studies and a study to test its pharmacologic effects on cardiac repolarization."

"The results of this latest trial support our belief that ST-246 is likely to meet the FDA's requirements for being safe and well-tolerated.  We are now in the planning stage for our expanded safety study of approximately 450 volunteers and are working with the FDA on establishing a protocol for the trial. Enrollment is expected to begin once the procedures have been determined," said Dr. Eric Rose, SIGA's Chief Executive Officer.

"As we move toward the goal of commercializing ST-246, our efforts are now directed towards completing the human and animal studies needed for regulatory approval. We are also advancing our efforts to obtain approval on additional indications for ST-246. Separately, we continue to make progress with our clinical pipeline of novel antivirals and apply for non-dilutive government grants and funding," Dr. Rose concluded.

This project was funded in whole or in part with federal funds from the Biomedical Advanced Research and Development Authority, Department of Health and Human Services, in conjunction with the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN266200600014C.