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-naïve. 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.