Daclatasvir recipients achieving protocol-defined response ( PDR ; HCV-RNA < lower limit of quantitation at Week 4 and undetectable at Week 10 ) were rerandomised at Week 12 to continue daclatasvir/peginterferon-alfa -2 a/ribavirin for 24weeks total duration or to placebo/peginterferon-alfa -2 a/ribavirin for another 12weeks .