The importance of HCV RNA measurement for tailoring treatment duration.

The introduction of telaprevir and boceprevir in the treatment of chronically HCV genotype 1 infected patients has led to substantially improved sustained virologic response rates and shorter treatment duration for a growing group of patients. Management and monitoring of patients receiving protease inhibitor-based triple therapy is of major importance and has become more complicated. Close monitoring of HCV RNA levels for patients on protease inhibitor-based therapy to identify subjects who are eligible for shortening of treatment duration, are virological non-responders or are in danger of experiencing a viral breakthrough is strongly recommended. Several virological tools including qualitative and quantitative HCV RNA assays for detection and quantification of HCV RNA are commercially available. We review these methods and their implications for HCV therapy as well as current sustained virologic response definition, stopping rules and recommendations for protease inhibitor-based treatment durations.