New protease inhibitors for the treatment of chronic hepatitis C: a cost-effectiveness analysis

Abstract

Background: Chronic hepatitis C virus is difficult to treat and affects approximately 3 million Americans. Protease inhibitors increase the effectiveness of standard therapy, but they are costly. A genetic assay may identify patients most likely to benefit from this treatment advance.

Objective: To assess the cost-effectiveness of new protease inhibitors and an interleukin (IL)-28B genotyping assay for treating chronic hepatitis C virus.

Design: Decision-analytic Markov model.

Data sources: Published literature and expert opinion.

Target population: Treatment-naive patients with chronic, genotype 1 hepatitis C virus monoinfection.

Time horizon: Lifetime.

Perspective: Societal.

Intervention: Strategies are defined by the use of IL-28B genotyping and type of treatment (standard therapy [pegylated interferon with ribavirin]; triple therapy [standard therapy and a protease inhibitor]). Interleukin-28B-guided triple therapy stratifies patients with CC genotypes to standard therapy and those with non-CC types to triple therapy.

Outcome measures: Discounted costs (in 2010 U.S. dollars) and quality-adjusted life-years (QALYs); incremental cost-effectiveness ratios.

Results of base-case analysis: For patients with mild and advanced fibrosis, universal triple therapy reduced the lifetime risk for hepatocellular carcinoma by 38% and 28%, respectively, and increased quality-adjusted life expectancy by 3% and 8%, respectively, compared with standard therapy. Gains from IL-28B-guided triple therapy were smaller. If the protease inhibitor costs $1100 per week, universal triple therapy costs $102,600 per QALY (mild fibrosis) or $51,500 per QALY (advanced fibrosis) compared with IL-28B-guided triple therapy and $70,100 per QALY (mild fibrosis) and $36,300 per QALY (advanced fibrosis) compared with standard therapy.

Results of sensitivity analysis: Results were sensitive to the cost of protease inhibitors and treatment adherence rates.

Limitation: Data on the long-term comparative effectiveness of the new protease inhibitors are lacking.

Conclusion: Both universal triple therapy and IL-28B-guided triple therapy are cost-effective when the least-expensive protease inhibitor are used for patients with advanced fibrosis.

Primary funding source: Stanford University.

Figure 1. Model Schematics

The small square represents the decision to implement a policy of standard therapy, universal triple therapy, or IL-28B guided triple therapy. The small circle with inset M indicates the Markov model. During each 12-week cycle of the model, all individuals face a risk of death depending on their age and health state. Individuals begin the model receiving treatment and if treatment is successful (the patient achieves sustained viral response) the patient may transition along one of the dashed arrows to a fibrosis-stage stratified recovered state. Treatment effectiveness is determined by type of treatment, race, fibrosis stage, and IL-28B genotype. If treatment is not successful the individual continues progressing through the natural history of HCV (indicated by solid arrows). Death can occur from any health state in the Markov model.

Figure 2. Cost-effectiveness Results: incremental costs incurred and quality-adjusted lifeyears (QALYs) experienced for each intervention (a) Boceprevir, mild fibrosis (b) Boceprevir, advanced fibrosis (c) Telaprevir, mild fibrosis (d) Telaprevir, advanced fibrosis

The graph plots the incremental discounted quality adjusted life year (y-axis) and incremental discounted total expected lifetime costs (x-axis) for each treatment strategy separately for cohorts of patients with mild and advanced fibrosis. The solid lines represent the cost-effectiveness efficient frontier, those strategies that are potentially cost-effective depending on one’s willingness to pay per unit of health benefit gained, expressed as an incremental costeffectiveness ratio (ICER) (defined as the ratio of the additional costs of an intervention and its additional effects as compared to the next best alternative).

Figure 2. Cost-effectiveness Results: incremental costs incurred and quality-adjusted lifeyears (QALYs) experienced for each intervention (a) Boceprevir, mild fibrosis (b) Boceprevir, advanced fibrosis (c) Telaprevir, mild fibrosis (d) Telaprevir, advanced fibrosis

The graph plots the incremental discounted quality adjusted life year (y-axis) and incremental discounted total expected lifetime costs (x-axis) for each treatment strategy separately for cohorts of patients with mild and advanced fibrosis. The solid lines represent the cost-effectiveness efficient frontier, those strategies that are potentially cost-effective depending on one’s willingness to pay per unit of health benefit gained, expressed as an incremental costeffectiveness ratio (ICER) (defined as the ratio of the additional costs of an intervention and its additional effects as compared to the next best alternative).