Synthetic Biologics, Inc. (NYSE MKT: SYN), a late-stage clinical company developing therapeutics focused on the gut microbiome, today announced that it has commenced an underwritten public offering of shares of its common stock and warrants to purchase shares of its common stock. 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.

Cantor Fitzgerald & Co. is acting as the sole book-running manager for the offering.

Synthetic Biologics anticipates using the net proceeds from the offering primarily to provide necessary funding for the continued clinical development of SYN-010, including initiation of its planned Phase 2b/3 clinical trial of SYN-010, and progression of SYN-004 to Phase 2 data readout and initiation of the planned Phase 3 clinical trial for SYN-004. In addition, a portion of the net proceeds may be used for general corporate purposes, which may include, among other things, payment of general and administrative expenses and accounts payable, increasing working capital, funding research and development and clinical trials of Synthetic Biologics' other product candidates and funding capital expenditures. Synthetic Biologics may also use a portion of the net proceeds for licensing or acquiring intellectual property to incorporate into its products and product candidates or its research and development programs, and to in-license, acquire or invest in complementary businesses or products and intellectual property.

About Synthetic Biologics, Inc.

Synthetic Biologics, Inc. (NYSE MKT: SYN) is a late-stage clinical company developing therapeutics focused on the gut microbiome. The Company's lead candidates poised for Phase 3 development are: (1) SYN-010 which is intended to reduce the impact of methane producing organisms in the gut microbiome to treat an underlying cause of irritable bowel syndrome with constipation (IBS-C), and (2) SYN-004 (ribaxamase) which is designed to protect the gut microbiome from the effects of certain commonly used intravenous (IV) beta-lactam antibiotics for the prevention of C. difficile infection, antibiotic-associated diarrhea (AAD) and the emergence of antibiotic-resistant organisms. The Company is also developing preclinical stage monoclonal antibody therapies for the prevention and treatment of pertussis and novel discovery stage biotherapeutics for the treatment of phenylketonuria (PKU).