Utilization and effectiveness of elbasvir/grazoprevir and adoption of resistance-associated substitutions testing in real-world treatment of hepatitis C virus genotype 1A infection: results from the German Hepatitis C-Registry

Background For treatment of genotype 1a (GT1a) infection with elbasvir/grazoprevir, the German guidelines recommend a differentiated approach depending on baseline viral load (BVL). For low BVL <= 800 000 IU/mL, treatment with 12 weeks elbasvir/grazoprevir should be considered, whereas for high BVL >800 000 IU/mL, this regimen is only recommended in nonstructural protein 5A (NS5A) resistance-associated substitutions (RAS) absence. With present NS5A RAS or when RAS-testing is not available, 16 weeks elbasvir/grazoprevir + ribavirin is preferred. Here, we investigated the adherence to these recommendations and the effectiveness of elbasvir/grazoprevir in a large German Hepatitis C-Registry GT1a cohort. Methods From September 2016 until July 2018, 195 GT1a-infected patients were treated with elbasvir/grazoprevir +/- ribavirin for 12-16 weeks. The primary outcome was per protocol SVR12 or SVR24. Results Mean age was 50 years, 89% were male, 19% had cirrhosis, 72% were treatment-naive. Forty-five percent had low BVL <= 800 000 IU/mL, 55% high BVL >800 000 IU/mL, of whom 49 vs. 42% were baseline RAS-tested. Four patients with high (7.7%) and two with low BVL (5%) had NS5A RAS of whom 50% received elbasvir/grazoprevir+ribavirin, respectively. Ninety-four percent of patients with low and 65% with high BVL received elbasvir/grazoprevir without ribavirin. Thirty-five percent of patients with high BVL received ribavirin, mostly without prior RAS-testing. Per protocol sustained virologic response (SVR) by low vs. high BVL was 98.8 and 95.1%. All patients with NS5A RAS achieved SVR. Conclusions In German, real-world most patients received elbasvir/grazoprevir without ribavirin. Ribavirin was mainly added in GT1a patients >800 000 IU/mL, who were not NS5A RAS tested. SVR rates were consistently high and comparable to clinical trial results. (C) 2020 The Author(s). Published by Wolters Kluwer Health, Inc.