Synthetic Biologics to Host Multiple Sclerosis-Estriol Investor Day in New York City on June 25, 2013

— Keynote Speaker, Rhonda R. Voskuhl, M.D., Director of the Multiple Sclerosis Program at UCLA, to Address the Role of Estriol in the Treatment of Multiple Sclerosis —

ROCKVILLE, Md., June 13, 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 it will host a Multiple Sclerosis-Estriol Investor Day on Tuesday, June 25, 2013 from 9:00 a.m. to 11:00 a.m. at the InterContinental New York Barclay Hotel in New York City. This event will be accessible via a live webcast through the following internet link, https://viavid.webcasts.com/starthere.jsp?ei=1018556

Keynote speaker, Rhonda R. Voskuhl, M.D., will join Synthetic Biologics’ executive management remotely for the presentations. Dr. Voskuhl is Professor, Department of Neurology, Jack H. Skirball Chair in Multiple Sclerosis Research and Director, Multiple Sclerosis Program at UCLA School of Medicine, and the lead investigator of the Phase II clinical trial evaluating the Company’s oral estriol product candidate, Trimesta, for the treatment of relapsing-remitting multiple sclerosis (MS). An overview of MS and the current market, as well as the history of estriol and its role in the treatment of MS will be discussed.

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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SOURCE Synthetic Biologics, Inc.