Impact of HCV kinetics on treatment outcome differs by the type of real-time HCV assay in NS3/4A protease inhibitor-based triple therapy

- Of the HCV RNA samples undetectable by CAP/CTM, 15.4% were detectable by ART.
- Rapid viral response by ART was associated with SVR by difficult-to-treat patients.
- 33.1% of the patients experienced the reappearance of residual HCV RNA (detectable/- Reappearance of residual HCV RNA by ART in the early stage of treatment was not related to treatment failure.
- Reappearance of residual HCV RNA by ART in the late stage or after the end of treatment could be an indicator of relapse.

Repeated measurement of the HCV RNA level is essential for properly monitoring treatment efficacy. The aim of this study was to determine the utility of two HCV real-time assays in the evaluation of the impact of hepatitis C virus (HCV) kinetics on the outcome of triple therapy with NS3/4A protease inhibitors (PIs), telaprevir or simeprevir. This study consisted of 171 Japanese patients infected with HCV genotype 1. All 3266 serum samples taken during and post treatment were tested with both the COBAS AmpliPrep/COBAS TaqMan (CAP/CTM) HCV Test v2.0 and the Abbott RealTime (ART) HCV Test. Of the 2597 samples undetectable (lower limit of detection [