Prior partial responders ( N = @ ) were randomized to @ weeks of twice-daily danoprevir/r @/@mg , mericitabine @ mg and ribavirin @/@ mg ( IFN-free ) ; danoprevir/r plus PegIFN alfa-@a / ribavirin ( triple ) ; or danoprevir/r , mericitabine and PegIFN alfa-@a / ribavirin ( Quad ) .