Merck has reported positive results from two pivotal Phase III studies of boceprevir, an investigational oral hepatitis C protease inhibitor.

The results showed that boceprevir demonstrated significantly higher sustained virologic response rates in the patients for chronic hepatitis C virus genotype 1 compared to control, the primary endpoint.

The HCV RESPOND-2 trial enrolled 403 adults with chronic hepatitis C genotype 1 who had failed prior therapy, while the HCV SPRINT-2 trial enrolled 1,097 adults with the condition but were new to treatment.

The studies were designed to evaluate if the addition of boceprevir to Pegintron and Rebetol (Peg/riba) could improve sustained virologic response rates and potentially shorten overall treatment duration compared to Peg/riba alone for 48 weeks, which is the current standard of care.

Following positive results, Merck has initiated the submission of a new drug application for boceprevir to the US Food and Drug Administration.