Synthetic Biologics Initiates Manufacturing Process for C. difficile Infectious Disease Program

— FUJIFILM Diosynth Biotechnologies UK Limited to Evaluate Expression of Company’s Proprietary Beta-Lactamase Enzyme, SYN-004 —

ROCKVILLE, Md., July 18, 2013 /PRNewswire/ — Synthetic Biologics, Inc. (NYSE MKT: SYN), a developer of biologics focused on the prevention and treatment of serious infectious diseases, announced today the initiation of the manufacturing process of the Company’s proprietary beta-lactamase enzyme (SYN-004) to target the prevention of Clostridium difficile (C. difficile or C. diff) infections. Pursuant to an agreement with FUJIFILM Diosynth Biotechnologies UK Limited (Fujifilm), the initial phase of the SYN-004 manufacturing process is underway with the evaluation of beta-lactamase protein expression in Fujifilm’s pAVEway™ platform. SYN-004 will be evaluated for production cell line yields as well as biological activity of the enzyme product.

“Initiating this expression platform evaluation with Fujifilm is an important first step in the SYN-004 manufacturing process. These efforts move us toward our goal of developing a prophylactic to prevent the devastating effects of C. diff infections, for which there is currently no vaccine or other approved preventive therapy,” stated Jeffrey Riley, Chief Executive Officer of Synthetic Biologics. “Upon completion of production cell line evaluation and selection of the optimal expression clone, we intend to proceed rapidly with manufacturing of preclinical material for animal studies, and cGMP production of SYN-004 for clinical studies.”

Steve Bagshaw, Managing Director of Fujifilm Diosynth Biotechnologies UK Limited said, “We are excited to have the opportunity to demonstrate to Synthetic Biologics the versatility of our pAVEway™ expression system for SYN-004 production.”

SYN-004: Targeting the Prevention of C. difficile Infections

In November 2012, Synthetic Biologics, Inc. acquired a series of oral beta-lactamase enzymes (P1A, P2A and P3A) and related assets targeting the prevention of C. difficile infections (CDI), the leading cause of hospital acquired infections (HAI), that generally occur secondary to treatment with intravenous antibiotics. The acquired assets include a pre-Investigational New Drug (IND) package for SYN-004, a 2nd generation oral enzyme candidate (formerly known as Ipsat Therapeutics P3A); Phase I and Phase II clinical data for P1A (a 1st generation oral enzyme candidate); manufacturing processes and data; and, a portfolio of issued and pending U.S. and international patents intended to support an IND and Biologic License Application (BLA) with the U.S. Food and Drug Administration.

Utilizing this portfolio of assets, the Company intends to develop a proprietary oral beta-lactamase enzyme product candidate, SYN-004. When co-administered with certain intravenous beta-lactam antibiotics, it is expected that SYN-004 can degrade the antibiotic that is excreted in the gastrointestinal (GI) tract, thus preserving the natural balance of the patient’s microflora, and preventing opportunistic infections including CDI. Beta-lactam antibiotics are a mainstay in hospital infection management and include the commonly used penicillin and cephalosporin classes of antibiotics. In 2012, 15 million Americans were administered beta-lactam antibiotics.*

Compared to the 1st generation oral enzyme candidate, P1A, the Company believes that SYN-004 will be able to degrade a broader spectrum of beta-lactam antibiotics, including both penicillins and cephalosporins. Due to the structural similarities between P1A and SYN-004 for the prevention of CDI, along with previous discussions with the FDA, it is anticipated that certain preclinical data collected on P1A may be used in support of an IND for the Company’s new product candidate, SYN-004.

About Clostridium difficile (C. difficile) Infections

According to the Agency for Healthcare Research and Quality, aggregate costs associated with CDI-related stays in the hospital were $8.2 billion in the U.S. during 2009. CDI is a rising global HAI problem in which the toxins produced by C. difficile bacteria result in diarrhea (C. difficile-associated diarrhea (CDAD)), and in the most serious cases, pseudomembranous colitis (erosion of the lower GI tract) that can lead to death. CDI is a major, unintended risk associated with the prophylactic or therapeutic use of intravenous antibiotics, which may alter the natural balance of microflora that normally protect the GI tract, leading to C. difficile overgrowth and infection. Other risk factors for CDI include hospitalization, prolonged length of stay, underlying illness, immune-compromising conditions including the administration of chemotherapy, and advanced age.

CDI is a widespread and often drug resistant infectious disease, and it is estimated that 1.1 million patients are infected with C. diff annually in the U.S.* Controlling the spread of CDI has proven challenging, as the C. difficile spores are easily transferred to patients via normal contact with healthcare personnel and other inanimate objects. There is currently no vaccine or approved product for the prevention of C. diff infection.

About Fujifilm Diosynth Biotechnologies (http://www.fujifilmdiosynth.com)

FUJIFILM Diosynth Biotechnologies UK Limited is an industry leading biologics Contract Development and Manufacturing Organization. Fujifilm Diosynth Biotechnologies has extensive experience in the development and manufacturing of recombinant proteins, vaccines, monoclonal antibodies, among other large molecules expressed in a wide array of microbial, mammalian, and insect systems. The company offers a comprehensive list of services from microbial and mammalian cell line development, including its proprietary pAVEway™ system, to process development, analytical development, clinical and commercial manufacturing. Fujifilm Diosynth Biotechnologies is also located in Research Triangle Park, NC, USA as FUJIFILM Diosynth Biotechnologies U.S.A., Inc. Both sites have been FDA-approved for the production of commercial biologic products.

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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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 our intention to develop and commercialize a proprietary oral beta-lactamase enzyme product candidate using the acquired assets that will have the desired results, our intention to commence clinical trials and the expected size of the market for C. diff therapeutics. 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, our inability to timely commence or complete the clinical trials consistent with our current expectations and our inability to successfully develop, receive regulatory approvals for or to commercialize a new product candidate to prevent C. diff infection 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.

*This information is an estimate derived from the use of information under license from the following IMS Health Incorporated information service: CDM Hospital database for full year 2012. IMS expressly reserves all rights, including rights of copying, distribution and republication.

SOURCE Synthetic Biologics, Inc.