In this phase 3 randomised study of safety and observational study of efficacy , patients with HCV genotype 1 infection and chronic kidney disease ( stage 4-5 with or without haemodialysis dependence ) were randomly assigned to receive grazoprevir ( 100 mg , NS3/4A protease inhibitor ) and elbasvir ( 50 mg , NS5A inhibitor ; immediate treatment group ) or placebo ( deferred treatment group ) once daily for 12 weeks .