Cost per response for abatacept versus adalimumab in patients with seropositive, erosive early rheumatoid arthritis in the US, Germany, Spain, and Canada

Background Effective treatment of rheumatoid arthritis (RA) with biologic DMARDs poses a significant economic burden. The AMPLE (Abatacept versus adaliMumab comParison in bioLogic-naivE RA subjects with background methotrexate) trial was a head-to-head, randomized study comparing abatacept with adalimumab. A post hoc analysis showed improved efficacy for abatacept in patients with versus without seropositive, erosive early RA. Objective The aim of the current study was to evaluate the cost per response (ACR20/50/70/90 and HAQ-DI) and patient in remission (DAS28-CRP, CDAI, and SDAI) for abatacept relative to adalimumab, in patients with seropositive, erosive early RA in the US, Germany, Spain, and Canada. Methods A previously published model was used to compare abatacept and adalimumab in a cohort of 1000 patients over 2 years. Clinical inputs were updated based on two subpopulations from the AMPLE trial. Cohort 1 included patients with early RA (disease duration <= 6 months), RF and/or ACPA seropositivity, and > 1 radiographic erosion. Cohort 2 included patients with RA in whom at least one of these criteria was absent. Results For cohort 1, all incremental costs per additional health gain (patient response or patient in remission) favoured abatacept in all countries, except for DAS28-CRP remission in Canada. Cost savings versus adalimumab were greater when more stringent response criteria were applied and also in cohort 1 patient (versus cohort 2 patients). Conclusion The cost per responder and patient in remission favoured abatacept in patients with seropositive, erosive early RA across all the countries. In this patient population, the use of abatacept instead of adalimumab can lead to lower costs in the US, Germany, Spain, and Canada.