Synthetic Biologics, Inc., a clinical stage company focused on developing therapeutics to protect the gut microbiome, announced positive topline results from the second phase 2a open-label clinical trial of SYN-004, the company's candidate designed to protect the gut microbiome from the unintended effects of certain commonly used intravenous (IV) beta-lactam antibiotics for the prevention of C. difficile infection (CDI), antibiotic-associated diarrhea (AAD) and the emergence of antibiotic-resistant organisms. Results from 14 participants who completed this clinical trial were analyzed to assess the ability of the 150 mg dose of SYN-004 to degrade ceftriaxone when administered alone and with the proton pump inhibitor (PPI), esomeprazole.

Consistent with previously reported results from the first phase 2a clinical trial, the second phase 2a trial demonstrated that the 150 mg dose of SYN-004 degraded residual IV ceftriaxone alone, and in the presence of a PPI, to levels that were near or below detectable in the intestinal chyme of healthy participants with functioning ileostomies. In addition, ceftriaxone plasma concentrations in study participants were very similar in the presence or absence of an oral PPI. The 150 mg dose strength of SYN-004 was well tolerated by all participants in this clinical trial.

"These topline data support the hypothesis that SYN-004 has the capacity to degrade residual IV ceftriaxone, in the presence of a PPI, thereby preserving the balance of the gut microbiome with the intent to prevent CDI, AAD and the emergence of antibiotic-resistant organisms, without affecting the antibiotic level in the bloodstream necessary for the treatment of primary infection," said Jeffrey Riley, president and chief executive officer of Synthetic Biologics. "Our phase 2b proof-of-concept, randomized, placebo-controlled clinical trial has enrolled over 210 patients to evaluate the ability of SYN-004 to prevent CDI and AAD in patients hospitalized with a lower respiratory tract infection and receiving IV ceftriaxone. An interim analysis of blinded data performed by an independent data monitoring committee is expected in summer of 2016."

Synthetic Biologics also announced that two abstracts have been accepted for poster presentation at ASM Microbe 2016. Both posters will be available for viewing in Halls A and B at the Boston Convention & Exhibition Center on June 17 as part of the "Experimental Therapeutics" session.