Background and Aim: A number of hepatitis C virus (HCV) patients without a rapid virological response (RVR) achieved a sustained virological response (SVR) with peginterferon-α-2a/ribavirin. The aim of this study was to identify factors associated with SVR in non-RVR patients.
Methods: Baseline and on-treatment factors were used to explore the prognostic factors for SVR in 113 HCV genotype-1 (HCV-1) and 20 HCV-2 non-RVR patients in two randomized trials.
Results: The SVR rate in HCV-1 patients with a complete early virological response (cEVR) and partial early virological response was 91.9% versus 45% (P < 0.001) and 21.4% versus 10% (P = 0.62), respectively, after 48 and 24 weeks of treatment. The SVR rate in HCV-2 patients with a cEVR was 90.9% versus 57.1% (P = 0.25), respectively, after 24 and 16 weeks of treatment. Multivariate analysis showed that cEVR and standard regimen were independently associated with SVR. Viral kinetic study revealed that HCV viral loads < 10 000 IU/mL at week 4 were the best predictor of cEVR for both HCV-1 and HCV-2 non-RVR patients with the accuracy of 81% and 95%, respectively, and also of SVR with the accuracy of 78% and 92%, respectively, in patients receiving standard of care. The most important independent predictors for cEVR were HCV viral loads < 104 IU/mL at week 4, followed by increased ribavirin dose within 12 weeks of treatment.
Conclusions: Achieving a cEVR with standard of care is the most important predictor of SVR in non-RVR patients. Week 4 viral loads < 10 000 IU/mL could accurately predict cEVR early and following SVR in non-SVR patients.