The cost-effectiveness of testing for NS5a resistance-associated polymorphisms at baseline in genotype 1a-infected (treatment-naïve and treatment-experienced) subjects treated with all-oral elbasvir/grazoprevir regimens in the United States.

BACKGROUND: The presence of baseline NS5A resistance-associated variants (RAVs) impacted treatment response in HCV genotype 1a (GT1a)-infected patients treated with elbasvir/grazoprevir (EBR/GZR) for 12 weeks, but not patients treated with EBR/GZR and ribavirin (RBV) for 16 weeks.

AIMS: To assess the cost-effectiveness of baseline testing for NS5A RAVs in EBR/GZR-treated patients compared without testing, and with current treatments for GT1a patients.

METHODS: We simulated the course of treatment with EBR/GZR, ledipasvir/sofosbuvir (LDV/SOF) and ombitasvir/paritaprevir/ritonavir+dasabuvir (3D) with or without RBV and natural history of disease of GT1a patients. Treatment-related data from clinical trials were used in a state-transition model of the natural history of chronic HCV GT1a infection and liver disease to project lifetime costs (US$2015) and quality-adjusted life years (QALY). Other clinical and economic inputs were estimated from published sources. We conducted base case and sensitivity analyses.

RESULTS: RAVs testing-guided treatment with EBR/GZR resulted in more QALYs than EBR/GZR without testing, 3D+RBV, or LDV/SOF8. This strategy was cost-saving relative to 3D+RBV or LDV/SOF8 and was cost-effective compared with EBR/GZR without testing. LDV/SOF12 was not cost-effective compared with the EBR/GZR RAVs testing-based strategy. Treatment with EBR/GZR guided by RAVs testing is the most effective regimen among treatment-experienced patients without cirrhosis and cirrhotic patients. In sensitivity analysis, RAVs testing was cost-effective in 48-55% and 63-85% among noncirrhotic and cirrhotic patients respectively.

CONCLUSIONS: RAVs testing before treatment with EBR/GZR is likely to be a cost-effective alternative to the use of EBR/GZR without testing, LDV/SOF, or 3D among GT1a treatment-naïve or treatment-experienced patients.