Safety and effectiveness of switching from infliximab to etanercept in patients with rheumatoid arthritis: results from a large Japanese postmarketing surveillance study.

Finding an effective treatment strategy for rheumatoid arthritis (RA) patients who have not benefited from previous tumor necrosis factor-α antagonist treatment is important for minimizing RA disease activity and improving patient outcomes. The aim of this study was to compare the safety and effectiveness of etanercept in patients with and without infliximab (IFX) treatment experience. Patients (n = 7,099) from a large postmarketing observational study of etanercept use in Japan were divided into 2 cohorts based on previous IFX use (pre-IFX and non-IFX). Baseline characteristics were assessed in each cohort. Adverse events (AEs) and European League Against Rheumatism (EULAR) responses were monitored every 4 weeks for 24 weeks. At baseline, pre-IFX patients were younger and had fewer comorbidities and a shorter RA duration than non-IFX patients. During the study, pre-IFX patients received concomitant methotrexate more often than non-IFX patients. The incidence of AEs and serious AEs were significantly lower in pre-IFX patients, as was the percentage of patients who discontinued treatment. Both cohorts had significant improvement (P < 0.001) in EULAR responses at the end of the treatment period. This study demonstrated that etanercept was effective and well tolerated in active RA patients with and without prior IFX treatment.