- The Food and Drug Administration requested additional trial data and analysis for Merck's investigational monoclonal antibody, bezlotoxumab, which is in development for secondary prevention of Clostridium difficile (C. diff), the company reported Thursday.
- The FDA cited concerns over the small trial sizes for the two main clinical trials, MODIFY 1 and MODIFY 2, compared to the large population of individuals affected by C. diff.
- With the request for more data, the FDA now expects to decide on bezlotoxumab by October 23, three months after its original projection of July 23.
In a report compiled by the Agency for Healthcare Research and Quality (AHRQ) in 2012, the incidence of C. diff has increased four-fold over the last two decades and accounted for 1% of all hospitalizations in 2009, showing an acute need for treatment as well as primary and secondary prevention strategies.
Merck's bezlotoxumab is a monoclonal antibody designed to prevent secondary infection by binding to and neutralizing the C. diff toxin.
The FDA's request could end up to be a more minor regulatory hurdle, but will delay the drug's development by several months and require more work from Merck.
And bezlotoxumab could win eventual support from the regulator. Just last month the FDA's Antimicrobial Drugs Advisory Committee voted 10-5 to recommend bezlotoxumab for approval, based the evidence Merck presented to support its safety and efficacy claims.