US Gives Merck’s Antitoxin Priority Review

The US Food and Drug Administration (FDA) has granted priority review to US drug maker Merck & Co for bezlotoxumab, an antitoxin for preventing the recurrence of Clostridium difficile (C. difficile) infection. The agency has given a Prescription Drug User Fee Act action date of Jul. 23, 2016.

Merck’s Biologics License Application was partly based on data from Phase I and II clinical trials. Bezlotoxumab is designed to neutralize C. difficile toxin B which can damage the bowel wall and cause inflammation, leading to diarrhea.

Roy Baynes, senior vice president of clinical development at Merck Research Laboratories, said recurrence of C. difficile infection is one of the most common healthcare-associated infections in US hospitals. Currently, here are no approved therapies available.

The European Medicines Agency is also reviewing the antitoxin.

Separately, following a priority review, the FDA has approved Merck’s Zepatier for treating adults with chronic hepatitis C genotype (GT) 1 or GT4 infection, with or without ribavirin.

In multiple clinical studies, Zepatier is said to have achieved high rates of sustained virologic response in the range 94-97% in GT1-infected patients and 97-100% in GT4-infected patients.