Utilization and effectiveness of elbasvir/grazoprevir (EBR/GZR) in treatment naïve (TN) genotype 1a (G1A) chronic hepatitis C virus (HCV) patients with/without baseline NS5A resistance-associated substitutions (RASS)

BACKGROUND: At baseline, the presence of virus with NS5A RASs has been shown to impact the efficacy of NS5A containing regimens in patients with G1a chronic HCV infection. Therefore, the purpose of the current analysis was to describe the utilization and effectiveness of EBR/GZR in G1a chronic HCV patients with or without NS5A RASs in the United States. METHODS: A subgroup analysis of an EBR/GZR treated cohort previously derived using data collected from US providers and specialty pharmacies through Trio Health's disease management platform was used. The cohort was restricted to TN chronic HCV G1a patients who initiated EBR/GZR therapy between Jan 28, 2016 (FDA approval) and Dec 31, 2016. The primary SVR analysis was a Per Protocol (PP) analysis defined as all patients that completed their intended therapy and who received an SVR testing at 12 weeks (SVR12) post therapy. RESULTS: 234 patients met the inclusion criteria for the subgroup analysis and NS5A RASs testing was conducted in 58% (135/234) of the cohort. Approximately 9% (12/135) of those tested had an NS5A RAS present. 50% (6/12) of these patients were treated for 16 weeks with ribavirin (RBV), 8% (1/12) for 12 weeks with RBV, 25% (3/12) were treated for 12 weeks without RBV, 17% (2/12) for 16 weeks without RBV. Of patients that did not have an NS5A RAS present, 95% (111/117) were treated for 12 weeks without RBV. At present, only 126 patients of the overall G1a cohort have completed therapy with an SVR12 of 98% (124/126) (TABLE). Of those with an NS5A RAS present, the SVR12 was 100% (2/2) in those treated for 16 weeks with RBV, 100% (1/1) in those treated for 12 weeks and 100% (1/1) in those treated for 16 weeks. The SVR12 was 98% (60/61) in those patients who did not have an NS5A RAS present. CONCLUSIONS: Based on preliminary data, EBR/GZR appears to be highly effective in treating G1a patients regardless of the presence of NS5A RASs. Full SVR data will be presented at the meeting (Table presented).