Suitable treatment period in patients with virological response during combination therapy of peginterferon and ribavirin for chronic hepatitis C.

Objective: The aim of this study was to determine the suitable treatment period in patients who achieve virological response during combination therapy of peginterferon and ribavirin for chronic hepatitis C virus infection.
Methods: Inclusion criteria were HCV-genotype 1b, serum HCV RNA level of > or =100 KIU/ml before treatment, and negativity of serum HCV RNA during treatment. The 366 patients were enrolled in this retrospective cohort study. Patients were classified into four groups according to difference of response: rapid-virological response (RVR) at week 4 after the initiation of treatment (n=37), early-virological response (EVR) at week 5-12 (n=161), late-virological response (LVR) at week 13-24 (n=131), and superlate-virological response (SLVR) at week 25-48 (n=37). A non-relapse in patients with undetectable HCV RNA during therapy was defined as clearance of HCV RNA 6 month after the cessation of therapy.
Results: Of the 366 patients, 241 had non-relapse and the non-relapse rate in each group was 89% (33/37) in RVR, 79% (127/161) in EVR, 54% (71/131) in LVR, and 27% (10/37) in SLVR. In RVR, 26 of 27 patients with continuance of negative HCV RNA of > or =30 weeks during treatment had non-relapse. In EVR, patients with period of negative HCV RNA of > or =40 weeks had non-relapse rate of 90% (71/79). In LVR and SLVR, all nine patients with continuance of negative HCV RNA of > or =60 weeks had non-relapse.
Conclusion: A suitable treatment period of combination therapy for chronic hepatitis C should be determined based on the time of attainment of negative HCV RNA.