Hepatitis C virus (HCV) infection is a common cause of liver disease in the UK. HCV can cause liver failure and liver cancer, and is a frequent indication for liver transplantation. HCV infection can be cured by antiviral therapy. Standard therapy includes the combination of pegylated interferon and ribavirin (PEG-IFN/RIBA) for 24 or 48 weeks, according to HCV genotype.^1–3 A sustained virological response (SVR), defined as undetectable serum HCV RNA six months after cessation of therapy, indicates successful treatment, almost certainly cure. Published registration trials reported encouraging SVR rates of 42–52% for genotype 1 and 77–88% for genotypes 2/3.^1–3

However, analysis of the combined experience of six European and US centres reported significantly worse results.⁴ In that report, the response rate to treatment of genotype 1 infection with pegylated IFN alpha 2a and ribavirin was only 36%. Also, a large US based prospective randomised study reported response rates of 29–34%, depending on the dose of ribavirin used.⁵ In contrast, a Canadian study that prospectively tracked patients receiving HCV treatment reported SVR rates …