Which patients with genotype 1 chronic hepatitis C can benefit from prolonged treatment with the 'accordion' regimen?

The on-treatment virological response to pegylated interferon plus ribavirin therapy is a useful tool in the management of patients with chronic hepatitis C. The time at which hepatitis C virus RNA becomes undetectable by a sensitive PCR assay has a huge impact on the probability of achieving a sustained virological response, particularly in genotype 1 patients, and may be useful in selecting patients for prolonged therapy. Indiscriminate extension of treatment in patients with hepatitis C virus genotype 1 is not beneficial. However, there is a subgroup of patients – the so-called ‘slow responders’ – who benefit from extending treatment from 48 to 72 weeks and can be readily identified after 4–12 weeks of combination therapy. Thus, it is important to distinguish slow responders from null responders. In the TeraVIC-4 study virological relapse rates were significantly lower, and sustained virological response rates were significantly higher, in those treated for 72 weeks with peginterferon alfa-2a (40 kDa) plus ribavirin (45% vs. 32% with 48 weeks, P = 0.014). Patients are best served by quantitative determination of the hepatitis C virus RNA level at weeks 4, 12 and 24. The results of these determinations can then be used to tailor the length of therapy.