The cost effectiveness of adalimumab in the treatment of moderate to severe rheumatoid arthritis patients in Sweden

Objective: Societal decision-makers increasingly emphasize their need for evidence-based economic analyses to make reimbursement decisions. The goal of this study was to analyse the cost utility of adalimumab, on both incremental cost and incremental health-value bases, vs. traditional disease-modifying antirheumatic drugs (DMARDs) and the other tumour necrosis factor (TNF) antagonists suitable for a submission to the Swedish LFN (Pharmaceutical Benefit Board). Adalimumab (Humira®, Abbott Laboratories) is a fully human anti-TNF monoclonal antibody for the treatment of rheumatoid arthritis (RA). Methods: This study implemented Swedish unit costs and treatment guidelines from a lifetime perspective. A mathematical model, incorporating data from eight trials on efficacy, utility and cost, simulated the experiences of 10,000 hypothetical moderate to severe RA patients for each strategy used in those trials. The primary outcome measure, quality-adjusted life years (QALYs), was derived from utility values calculated from a relationship between the Health Assessment Questionnaire (HAQ) disability index (DI) and Health Utility Index-3 (HUI-3) from adalimumab trial results. The model followed OMERACT guidance for incorporating mortality data, accounting for placebo, trending HAQ DI scores over different periods of a treatment cycle, and other factors. Results: In a cost-per-ACR50 analysis, adalimumab plus methotrexate showed the greatest number of QALYs gained (2.3 from one study and 2.1 from the pooled results of two trials). The etanercept plus methotrexate strategy yielded QALY gains similar to the pooled adalimumab results. Except for the infliximab strategy, the costs results are between €35,000–42,000, a range normally considered cost-effective in other European countries. Conclusion: Adalimumab is cost-effective for the treatment of moderate to severe RA. The results suggest that adalimumab is at least as cost-effective as the other TNF antagonists.