In QUEST-@ , a phase @ , randomised , double-blind multicentre trial undertaken in @ countries ( Australia , Europe , North America , Puerto Rico , and New Zealand ) , @ patients ( aged @ years ) with chronic HCV genotype @ infection and no history of HCV treatment , stratified by HCV subtype and host IL@B genotype , were randomly assigned in a @:@ ratio with a computer-generated allocation sequence to receive simeprevir ( @ mg once daily , orally ) plus peginterferon alfa @a plus ribavirin for @ weeks , followed by peginterferon alfa @a plus ribavirin ( simeprevir group ) , or placebo orally plus peginterferon alfa @a plus ribavirin for @ weeks , followed by peginterferon alfa @a plus ribavirin ( placebo group ) .