Efficacy and Safety of Etanercept Biosimilars Compared With the Originator for Treatment of Juvenile Arthritis: A Prospective Observational Study

OBJECTIVE: Analysis of etanercept biosimilars in pediatric patients with juvenile idiopathic arthritis (JIA) in comparison with the etanercept originator in terms of efficacy and safety. METHODS: Patients diagnosed with JIA who started treatment with either the etanercept originator or a biosimilar after January 1, 2017, were selected from the German BIKER registry (Biologics in Paediatric Rheumatology Registry). Furthermore, patients who started therapy with the originator and switched to a biosimilar during the course of therapy were identified. For both patient groups, disease activity and safety were examined and compared separately. RESULTS: After January 1, 2017, 348 patients started treatment with the etanercept originator (n = 293) or a biosimilar (n = 55). Another 57 patients switched to a biosimilar during the course of therapy. A significant decrease or a stable remission of disease activity was observed in both patient groups. The safety profiles were comparable, and frequencies and types of adverse events (AEs) and serious AEs were similar in patients starting therapy with the originator or a biosimilar. Only injection site reactions occurred slightly more frequently under biosimilar therapy, without having an impact on therapy adherence. In patients who switched therapy, the AE rate per 100 patient‐years was comparable before (26.4) and after (32.1) the switch. CONCLUSION: In patients with JIA who require treatment with etanercept, the originator is still used much more frequently. However, our study highlights the equivalence of etanercept biosimilars for therapy for JIA. Increased use of these biosimilars in pediatric patients can therefore be recommended without hesitation.