Former Pfizer/Wyeth Global Infectious Disease Pharmaceutical Executive, Lewis Barrett, Appointed Senior Vice President, Commercial Strategy of Synthetic Biologics, Inc.

— Company Strengthens Team to Support Pipeline of Infectious Disease Therapies —

ROCKVILLE, Md., Aug. 6, 2013 /PRNewswire/ — Synthetic Biologics, Inc. (NYSE MKT: SYN), a developer of biologics focused on the prevention and treatment of serious infectious diseases, announced today that Lewis (Lew) Barrett joined the Company as its Senior Vice President, Commercial Strategy. Mr. Barrett, former Assistant Vice President, Established Products at Pfizer and Vice President Global Business Manager, Infectious Diseases at Wyeth Pharmaceuticals, brings his expertise in the development, commercialization and launch of infectious disease product candidates to the Synthetic Biologics’ team.

As the senior marketing executive, Mr. Barrett successfully led, co-chaired or served on teams that focused on infectious diseases, oncology, transplantation, and hemophilia during his 25-year career at Wyeth (acquired by Pfizer in 2009). He brings to Synthetic Biologics his expertise in U.S. and global strategy, branding, clinical development, medical affairs, supply chain, business development and strategic alliance management. Mr. Barrett was instrumental in building the brand and led global commercialization efforts for Wyeth’s in-line IV antibiotic, Zosyn®/Tazocin® (the second IV antibiotic to achieve $1 billion+ in sales), and managed the U.S. launch of Wyeth’s broad-spectrum IV antibiotic, Tygacil®.

Prior to joining Synthetic Biologics as Senior Vice President, Commercial Strategy, Mr. Barrett served as an advisor to the Company since September 2012. Utilizing his depth of experience in the anti-infective, hospital and biopharma fields, Mr. Barrett provides strategic consultation to the global life sciences field with a particular focus on brand strategy, lifecycle strategy, business development, and strategic communications through LL Barrett Biopharmaceutical Consulting, LLC.

Mr. Barrett earned an M.B.A. from Temple University and a B.S. degree in Biology from Stockton State College.

“We are pleased to welcome Lew to the Synthetic Biologics’ team and expect that his extensive experience in the development and commercialization of anti-infectives will be vital to the Company as we develop SYN-004 for the prevention of C. difficile infections and monoclonal antibody therapies for the treatment of Pertussis and Acinetobacter infections,” stated Jeffrey Riley, Chief Executive Officer at Synthetic Biologics.

“We recently initiated the manufacturing process for our lead infectious disease candidate, SYN-004, intended to prevent the devastating effects of C. difficile infections, for which there is currently no vaccine or other approved preventive therapy. We look forward to benefiting from Lew’s knowledge and big pharma experience for our C. difficile program as well as the other programs in our infectious disease pipeline,” concluded Mr. Riley.

About Synthetic Biologics, Inc.

Synthetic Biologics, Inc. (NYSE MKT: SYN) is a biotechnology company focused on the development of biologics for the prevention and treatment of serious infectious diseases. The Company is developing an oral enzyme for the prevention of C. difficile infections, and a series of monoclonal antibody therapies for the treatment of Pertussis and Acinetobacter infections. In addition, the Company is developing a drug candidate for the treatment of relapsing-remitting multiple sclerosis and cognitive dysfunction in multiple sclerosis. For more information, please visit Synthetic Biologics’ website at www.therivabio.com.

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Zosyn®, Tazocin® and Tygacil® are registered trademarks of Pfizer or its affiliates.

This release includes forward-looking statements on Synthetic Biologics’ current expectations and projections about future events. In some cases forward-looking statements can be identified by terminology such as “may,” “should,” “potential,” “continue,” “expects,” “anticipates,” “intends,” “plans,” “believes,” “estimates,” and similar expressions. These statements are based upon current beliefs, expectations and assumptions and are subject to a number of risks and uncertainties, many of which are difficult to predict and include statements regarding the expected contribution of Mr. Barrett and the intended effects of our product candidate. The forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those set forth or implied by any forward-looking statements. Important factors that could cause actual results to differ materially from those reflected in Synthetic Biologics’ forward-looking statements include, among others, a failure to successfully integrate the new management and other factors described in Synthetic Biologics’ report on Form 10-K for the year ended December 31, 2012 and any other filings with the SEC. The information in this release is provided only as of the date of this release, and Synthetic Biologics undertakes no obligation to update any forward-looking statements contained in this release on account of new information, future events, or otherwise, except as required by law.

SOURCE Synthetic Biologics, Inc.