Early virologic response with pegylated interferons

Recently, 12-week evaluation of viral response has been recommended as a means of reducing antiviral treatment morbidity and costs. The development of early stopping rules relies on an important assumption: rules must minimise discontinuation of treatment in patients who might ultimately respond after completion of the full course of therapy. Minimising loss of potential responders is the most important clinical goal in defining an early stopping rule because it provides the most sustained virological responders. This definition of the rule relies on maximising the negative predictive value. Conversely, rules that select patients based on optimising the positive predictive value produce the highest proportion of sustained responders and may discontinue treatment in more patients, thus reducing immediate costs, but will necessarily exclude some patients who would achieve response with continued therapy and reduce the total number of sustained responders. In conclusions, in patients treated with PEG-IFN α-2b or α-2a combination therapy, the decision to continue or stop treatment can be made as early as week 12. However, individual decisions to continue antiviral treatment should also consider the variability in the accuracy of quantitative viral assays, patient preferences, and the pending results of ongoing studies of treatment maintenance in those with advanced fibrosis.