[METHODS] In QUEST-1 , a phase 3 , randomised , double-blind multicentre trial undertaken in 13 countries ( Australia , Europe , North America , Puerto Rico , and New Zealand ) , 394 patients ( aged 18 years ) with chronic HCV genotype 1 infection and no history of HCV treatment , stratified by HCV subtype and host IL28B genotype , were randomly assigned in a 2:1 ratio with a computer-generated allocation sequence to receive simeprevir ( 150 mg once daily , orally ) plus peginterferon alfa 2a plus ribavirin for 12 weeks , followed by peginterferon alfa 2a plus ribavirin ( simeprevir group ) , or placebo orally plus peginterferon alfa 2a plus ribavirin for 12 weeks , followed by peginterferon alfa 2a plus ribavirin ( placebo group ) .