Merck announced results from multiple analyses at The Liver Meeting(R) 2016, which provide additional evidence supporting the use of ZEPATIER(TM) (elbasvir and grazoprevir) 50mg/100mg tablets in chronic hepatitis C virus (HCV) genotype (GT) 1- or GT4-infected patient populations, including those who receive opioid agonist therapy (OAT), are infected with chronic HCV GT1b, use proton pump inhibitors (PPIs) or have moderate kidney disease. The study does not exclude patients who are actively using drugs with high abuse potential. Primary efficacy and safety results from C-EDGE CO-STAR were previously presented at The Liver Meeting(R) in November 2015. Interim results presented on November 12, 2016 are from the ongoing 3YFU study. The median time from the end-of-treatment (EOT) in the C-EDGE CO-STAR study to the first visit as part of the 3YFU study was 330 days (range: 206-485). Of the 199 patients in the 3YFU study, 108 (54%) reported any drug use (non-injecting or injecting) in the past six months, 40 of whom (37%) reported injection drug use in the past month. At the first visit in the 3YFU study, two individuals (1%) tested positive for evidence of HCV, suggesting that chronic HCV reinfection was uncommon among patients on OAT in the first year following treatment with ZEPATIER, despite ongoing drug use. GT1b Integrated Analysis. A retrospective integrated analysis of data from 11 Phase 2 and Phase 3 trials in the clinical development program for ZEPATIER was conducted to evaluate its efficacy in patients infected with GT1b, the most common chronic HCV genotype globally and the second-most common in the United States. The analysis included 1,070 patients with chronic HCV GT1b infection who received ZEPATIER for 12 weeks, including: patients who were treatment naïve or had prior experience with peginterferon alfa/interferon and ribavirin (RBV), with or without an NS3/4A protease inhibitor; those who were compensated cirrhotic or non-cirrhotic; and those with or without HIV-1 co-infection. The analysis showed 97% of patients (1040/1070) achieved sustained virologic response 12 weeks after the completion of therapy (SVR12, considered virologic cure). Of the patients who did not achieve SVR12, 15 were virologic failures (1%) and 15 patients were lost to follow-up (1%). Rates of SVR12 were consistently high regardless of patient characteristics, including prior treatment experience (97%, 212/219), presence of compensated cirrhosis (99%, 188/189) and HIV-1 co-infection (94%, 51/54). Serious adverse events occurred in 3% of patients (35/1070) who received active treatment, and 2.9% (3/105) of those who received placebo in studies that included a placebo arm. Pooled Analysis in Patients with Self-Reported PPI Use. This post-hoc analysis of patients with chronic HCV GT1 and GT4 infection in six studies in the Phase 3 clinical program for ZEPATIER assessed SVR12 among patients who self-reported concomitant use of proton pump inhibitors (PPIs).