Drug reduces risk of Clostridium difficile bacterium infection

An experimental antibody developed by Merck & Co Inc was shown in pivotal studies to reduce by about 10 percentage points the risk that infection with Clostridium difficile bacterium, which can cause a deadly diarrhea, will recur.

In the US, C. difficile infects nearly half a million people a year and contributes to around 29,000 deaths. The infection is treated with standard antibiotics, which also wipe out friendly bacteria that normally control C difficile.

Merck said two Phase 3 studies, presented on Sunday at a medical meeting in San Diego, found 12 weeks of treatment with antibiotics and a one-time infusion of bezlotoxumab, designed to block the ability of a toxin to bind to cells, reduced to about 15 percent the risk that C. difficile would recur.