Optimizing the position and use of omalizumab for severe persistent allergic asthma using cost-effectiveness analysis

Abstract

Background: There has been some controversy on whether the costs of omalizumab outweigh its benefits for severe persistent allergic asthma.

Objectives: This study aimed to resolve the uncertainties and limitations of previous analyses and establish the cost-effectiveness of omalizumab under the list price and Patient Access Scheme (PAS) discounted price for the UK National Health Service.

Methods: A decision-analytic model was developed to evaluate the long-term cost-effectiveness of omalizumab under the perspective of the National Health Service. Outcomes were expressed as quality-adjusted life-years (QALYs). Patient subgroups were defined post hoc on the basis of data collected in clinical trials: previous hospitalization, on maintenance oral corticosteroids, and three or more previous exacerbations.

Results: The incremental cost-effectiveness ratio varied from £30,109 to £57,557 per QALY gained depending on the population considered using the PAS price; incremental cost-effectiveness ratios were over a third higher using the list price. Omalizumab is likely to be cost-effective at the threshold of £30,000 per QALY gained in the severe subgroups if the improvement in health-related quality of life from omalizumab is mapped from an asthma-specific measure to the EuroQol five-dimensional questionnaire (vs. the EuroQol five-dimensional questionnaire directly collected from patients) or asthma mortality refers to death after hospitalization from asthma (vs. asthma-mortality risk in the community).

Conclusions: Although the cost-effectiveness of omalizumab is more favorable under the PAS price, it represents good value for money only in severe subgroups and under optimistic assumptions regarding asthma mortality and improvement in health-related quality of life. For these reasons, omalizumab should be carefully targeted to ensure value for money.

Keywords: asthma; decision-analytic model; economic evaluation; omalizumab.