Two cohorts (A and B) of patients with chronic HCV infection will be enrolled. Patients will be eligible for enrollment if they fulfill the study inclusion and exclusion criteria and have achieved a complete tumour response (CR) 3 months (+/- 14 days) following HCC treatment~Cohort A: Patients with Barcelona Clinic Liver Cancer (BCLC) stage 0 or A HCC who have received curative therapy defined as either; liver transplantation, surgical resection or local ablation with curative intent and attained a radiologically confirmed CR. (N=50)~Cohort B: Patients who are non-eligible for curative therapy but have attained a radiologically confirmed CR. post embolization or ablative therapy and have chronic HCV infection. (N=50) Given the existing uncertainty regarding the impact of direct acting antiviral (DAA) therapy on HCC recurrence, study participants will be randomized to receive DAA treatment as immediate ie upon study enrollment or delayed ie treatment commenced ≥ 6months following documentation of complete response based on radiological assessment indicating no residual arterial enhancing disease..
Subjects with Hepatitis C Virus (HCV) infection, genotype 1 or 4 and with hepatocellular carcinoma (HCC) and a complete response to HCC therapy will be randomised to immediate or delayed (6 months) HCV therapy with Elbasvir (MK-8742) and Grazoprevir (MK-5172) [EBR/GZR].