Microbiome Therapy for C. diff Clears Phase 2 Clinical Trial

Ribaxamase significantly reduced Clostridium difficile infection in a mid-stage clinical trial involving more than 400 patients.

Joshua A. Krisch
Jan 5, 2017

Clostridium difficile colonies on blood agarCDC, HOLDEMANClostridium difficile (C. diff ) is one of the most common hospital-acquired infections, in part because of its ability to opportunistically colonize the GI tract after antibiotics have disrupted the natural balance of the gut microbiome. But results from a Phase 2 clinical trial announced yesterday (January 5) suggest that Synthetic Biologics’s SYN-004 (ribaxamase) may help degrade certain antibiotics within the GI tract, maintaining the status quo in the gut microbiome and preventing C. diff infection.

The randomized, double-blind trial involved 412 patients, half of whom received 150 mg of ribaxamase and half of whom received a placebo. By the end of the trial, there were seven cases of C. diff infection in the placebo group but only two in the test group, representing a 71.4 percent relative risk reduction.

The successful trial represents “a significant milestone in the clinical development...

Ribaxamase, an oral enzyme, targets beta-lactam antibiotics, which can save lives but also wreak havoc on the gut microbiome, paving the way for the 453,000 C. diff infections and 29,000 C. diff–related deaths in the U.S. each year, according to the Centers for Disease Control and Prevention.

“The trial results provide a compelling demonstration of the potential of ribaxamase,” said Joseph Sliman, senior vice president of clinical and regulatory affairs at Synthetic Biologics, in the press release.