Synthetic Biologics Inc. (SYN) said its oral enzyme-based drug SYN-004 (ribaxamase) for antibiotic-resistant infections like C. difficile outperformed a placebo in a Phase 2b trial. A placebo is a substance that has no therapeutic effect, and is used as a control in testing new drugs.

In the trial, SYN-004 met the primary endpoint of significantly decreasing the C. difficile infection. Results of the mid-stage study, which tested 412 patients, indicated only two cases of C. difficile infection in the ribaxamase treatment group against seven in the placebo group.

Synthetic Biologics, of Rockville, Maryland, develops drugs based on preserving microbiomes, which are microorganisms in the body. Ribaxamase drug is Synthetic Biologics’ first-in-class oral enzyme drug, which is designed to protect gut microbiomes from disruption caused by certain intravenous beta-lactam antibiotics.

The recent success will give a big push to company’s efforts in establishing the potential of the microbiome class of drugs aimed at treating serious diseases affecting public health. (See also: Synthetic Biologics Wins Research Contract.)

 “(We) look forward to continuing ongoing and productive discussions with both the FDA and CDC on the protocol for Phase 3 pivotal trials for ribaxamase," said Synthetic Biologics CEO Jeffrey Riley. 

Antibiotic-resistant infections, like C. difficile, are a leading cause of watery diarrhea, fever, nausea, abdominal pain, and inflammation of the colon. They are commonly spread by hospital surfaces and human contact, and pose big threat to public health and safety.

The human digestive contains a lot of good or favorable bacteria, which get killed by the antibiotic drugs administered for treating infections like C. difficile. As these bacteria play important role in many body functions and have a decisive impact on other factors like depression and obesity, their death leads to weakening of the body’s own defense and impairment of body’s development.

Ribaxamase drug works by saving such favorable bacteria found in the digestive system from the adverse effects of intravenous antibiotic drugs.