OBJECTIVES: Etanercept and adalimumab are TNF inhibitors, both indicated in the UK for the treatment of patients with moderate-to-severe active rheumatoid arthritis (RA) who had inadequate response to disease-modifying antirheumatic drugs (DMARDs). The objective of this study was to assess the cost impact of etanercept compared to adalimumab when considering dose escalation.

METHODS: A budget impact model was developed to assess the drug cost impact of etanercept versus adalimumab, from the perspective of the UK national healthcare payer over a one-year time horizon. The modelled population represented 79,762 patients with RA who were biologic-naïve (previously failed on DMARDs) and who were treated with either etanercept or adalimumab. Clinical inputs in the model included response (ACR20) to treatment, with patients who did not respond to the initial dose experiencing dose escalation. Applying Phase III trial data, 65% of patients treated with etanercept and 53% of patients treated with adalimumab responded to their initial dose within 3 months. Based on a published systematic literature review, the model assumed a weighted mean of 14.9% of patients who did not respond to the initial dose of adalimumab and subsequently received dose escalation. Dose escalation was not considered for etanercept as it is not specified in the label. Drug costs were taken from published UK sources. Primary model outcomes were the total costs of etanercept versus adalimumab cohorts and net budget impact over one year.

RESULTS: Annual drug costs in the adalimumab and etanercept UK cohorts were £768.4 million and £741.4 million, respectively. Treatment with adalimumab resulted in a £27.0 million increased spend compared to the etanercept cohort. Alternative scenarios around dose escalation were explored and were consistent with base case findings.

CONCLUSIONS: Treatment with etanercept may yield cost savings versus adalimumab in the UK for biologic-naïve patients with RA, when considering adalimumab dose escalation.