Objectives: To evaluate the effectiveness and safety of non-medical switching from reference to biosimilar etanercept in adult patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) or axial spondyloarthritis (axSpA) using different information strategies before switching.
Methods: Data of adult patients with RA, PsA or axSpA who had received reference etanercept were retrospectively analysed. Whether or not patients were informed about the switch from reference to biosimilar etanercept was left to the discretion of the treating rheumatologist. Disease activity and function were regularly assessed in two consecutive visits (week 12 and 24). The scores documented at week 12 week after the switch were defined as primary outcome. Adverse drug events (ADE) were documented.
Results: Data of 84 patients were available (44 RA, 25 axSpA and 15 PsA patients), of whom 24 had been informed about the planned switch (28.5%). The scores at week 12 of disease activity and function remained rather unchanged. Neither outcomes nor frequency of ADE were influenced by information strategy. The retention rate was high (96.4% at week 12, 87.6% at week 24). Seven patients were lost to follow-up, and six patients discontinued due to inefficacy or ADE. 18 ADEs were reported in 10 patients (12%). In 3 patients (3.6%) who had 5 ADEs in the first 12 weeks the reference etanercept was successfully readministered.
Conclusions: Systematic switch from reference to biosimilar etanercept was not associated with changes in disease activity or function in. This was independent of information on the switch transmitted to the patients.