We randomly assigned ( 1:1 ) patients ( stratified by HCV genotype 1 subtype [ 1a plus other/1b ] and previous treatment response [ partial or null ] ) to receive simeprevir ( 150 mg once a day ) plus telaprevir placebo ( three times a day 7-9 h apart ) or telaprevir ( 750 mg three times a day ) plus simeprevir placebo ( once a day ) in combination with peginterferon alfa-2a and ribavirin for 12 weeks followed by 36 weeks of peginterferon alfa-2a and ribavirin alone .