Efficacy and Safety of Biosimilar and Originator Etanercept in Rheumatoid Arthritis Patients: Real-Life Data

Background: There is a lack of real-life clinical data for biosimilar etanercept, an anti-TNF blocking fusion protein. We describe the comparable efficacy and safety of originator and biosimilar etanercept in rheumatoid arthritis (RA) patients in a real-life clinical setting. Our data confirm that a biosimilar etanercept can be safely used as first-line treatment as well as in patients switched from a previous originator compound. Objectives: To compare the efficacy and safety of originator and biosimilar etanercept in a cohort of RA patients attending two Italian hospitals. Methods: The study involved 81 consecutive adult RA patients treated for at least 6 months with originator or biosimilar etanercept and considered their clinical and laboratory data, concomitant medications, and adverse events at baseline, and after 3 and 6 months of treatment. Results: Group 1 included 51 patients taking originator etanercept; group 2 included 30 taking biosimilar etanercept, including 19 who had been switched from the reference product. Despite a significant baseline difference in clinical disease activity, one-way analysis of variance showed that the two groups were clinically comparable after 6 months of treatment, and the same was true when only those receiving etanercept as first-line biological treatment were considered. Nine patients discontinued the treatment due to inefficacy or adverse events, which were never serious and were only reported in group 1. Conclusions: The efficacy and safety profiles of originator and biosimilar etanercept are comparable in RA patients in a real-life clinical setting. Further studies are needed to confirm these preliminary findings.