AV2 - Cost-Effectiveness Analysis of Baseline Testing for Resistance-Associated Polymorphisms to Optimise Treatment Duration in Genotype 1 Non-Cirrhotic Treatment-Naïve Patients with Chronic Hepatitis C Virus

Abstract

Sustained virologic response (SVR) to direct-acting antiviral regimens containing non-structural protein 5A (NS5A) inhibitor over eight weeks is 95% in genotype 1 (GT1) non-cirrhotic treatment-naïve (TN) patients with hepatitis C virus (HCV). Patients with resistance to the NS5A inhibitor have lower SVR (<85%), and there is evidence that higher SVR (>95%) can be achieved with 12 weeks treatment. We compared the lifetime cost-effectiveness of testing for NS5A resistance at baseline and optimising treatment duration based on the presence of NS5A polymorphisms, using a UK National Health Service perspective. A decision tree and Markov model was used to simulate treatment outcomes and natural disease progression for GT1 non-cirrhotic TN patients in the UK. We compared baseline testing with ‘no testing’. Under ‘no testing’, patients received eight weeks treatment with ledipasvir/sofosbuvir (LDV/SOF). Under ‘testing’, patients with (15%) and without (85%) NS5A polymorphisms were given LDV/SOF for 12 and eight weeks, respectively. We modelled retreatment with the same regimen for 12 weeks in patients that failed initial treatment and considered different SVR thresholds. Evidence on model parameters were taken from published studies. Baseline testing for NS5A polymorphisms generated marginally higher lifetime costs (£32,593.78) and quality-adjusted life years (QALYs) (15.29) per 1,000 patients over ‘no testing’ (£31,207.36; 15.27), assuming 80% SVR to retreatment in each arm, and produced an incremental cost-effectiveness ratio (ICER) of £75,618.55. If the SVR rate for retreatment was 100% in those without NS5A polymorphisms, against 80% in other patients, the ICER was £30,797.79; if SVR was 70% in NS5A-resistant patients, the ICER was £33,289.90. Optimising treatment duration with LDV/SOF for HCV GT1 non-cirrhotic TN patients based on NS5A resistance is not cost-effective, unless high levels of SVR to retreatment are observed in patients with and without NS5A polymorphisms. Results are sensitive to the prevalence of NS5A polymorphisms and baseline test-costs.