Merck & Co is gearing up to file its investigational antitoxin bezlotoxumab in the US, Canada and Europe this year, after late-stage data backed the drug’s use in preventing the recurrence of Clostridium difficile infection.

In two Phase III trials - MODIFY I and MODIFY II - the rate of infection recurrence was significantly lower in patients taking bezlotoxumab (17.4% and 15.7%) and those taking a combination of bezlotoxumab and actoxumab (15.9% and 14.9%) compared to the placebo arms (27.6% and 25.7%), respectively. 

On the safety side, the rate of adverse reactions were found to be comparable across the bezlotoxumab and placebo arms, the most common observed in the two trials being nausea, diarrhoea, pyrexia and urinary tract infection.

“Results of these studies showed that a single, one-time infusion of the antitoxin bezlotoxumab given with standard of care C. difficile antibiotic treatment significantly reduced the recurrence of C. difficile infection compared to standard of care alone, and demonstrated this benefit over a 12-week period,” noted Mark Wilcox, Leeds Teaching Hospitals and University of Leeds, and a lead investigator for the studies.

If bezlotoxumab - a selective, fully-human, monoclonal antibody designed to neutralise C. difficile toxin - gains approval, it will give patients access to a treatment to prevent the superbug from recurring for the first time.