Prolonged PEG-IFN and RBV is effective in patients with HCV genotype 1 and high viral load who achieved virological response later than 24 weeks.

Objective: The extension of treatment duration has been proposed in late virological responders with hepatitis C virus (HCV) genotype 1 and high viral load. However, the effectiveness of extended treatment in patients whose serum HCV RNA become undetectable later than 24 weeks of treatment (ultra-late virological responder; ULVR) has not yet been determined.

Methods: A total of 130 patients infected with HCV genotype 1 and who had high viral load were treated with pegylated interferon (PEG-IFN) and ribavirin (RBV) combination therapy. We retrospectively analyzed 10 ULVR who received extended combination treatment beyond 48 weeks.

Results: The duration of the combination treatment for ULVR ranged between 59 and 119 weeks, and the mean duration was 80 weeks. Although the majority of ULVR were older female patients (> or = 60 years) with factors related to poor therapeutic response, 8 patients (80%) achieved sustained virological response (SVR). The SVR rate correlated well with the duration of the treatment. Five ULVR achieved SVR when treatment was continued until serum HCV RNA remained undetectable for longer than 48 weeks.

Conclusion: The extended duration of PEG-IFN and RBV combination treatment is a possible strategy to improve treatment response in HCV genotype 1 infection, even for ULVR.