Synthetic Biologics, Inc. (nyse mkt:SYN), a clinical-stage company focused on developing therapeutics to protect the microbiome while targeting pathogen-specific diseases, today announced that it has commenced an underwritten public offering of shares of its common stock. All of the shares in the offering are to be sold by Synthetic Biologics. The Company intends to grant the underwriters a 30-day option to purchase up to an additional 15 percent of the share amount sold to cover over-allotments, if any. The offering is subject to market conditions, and there can be no assurance as to whether or when the offering may be completed, or as to the actual size or terms of the offering.