The study will be a randomized, double blind, placebo controlled, dose rising study in Interferon alpha (IFN-alpha) non-responder HCV infected patients or HCV patients who have relapsed following IFN-alpha therapy. Eligible subjects must have compensated liver disease and serum HCV RNA concentrations above 100,000 IU/mL at screening. The study will include both a single dose period for the evaluation of acute toxicity and single dose pharmacokinetics and a consecutive multi-dose period for the determination of longer-term safety, multiple-dose pharmacokinetics and antiviral activity. The objectives of this study are to evaluate the safety, tolerability, and antiviral activity of escalating single and multiple doses of XTL 2125 in patients with chronic hepatitis C virus infection and to assess the single- and multiple-dose pharmacokinetics of XTL 2125