Review of Biosimilar Trials and Data on Etanercept in Rheumatoid Arthritis

Etanercept was the first tumour necrosis factor inhibitor approved to treat rheumatoid arthritis (RA) in the United States (US) and Europe. The recent patent expiration of the etanercept originator ENBREL in Europe has facilitated the development of biosimilar products, creating the prospect of reduced treatment costs. In this article, we review the original trials for etanercept in RA to facilitate critical appraisal of biosimilar trial data.

Two etanercept biosimilars are currently approved in Europe and/or the US, SB4 (Benepali) and GP2015 (Erelzi), having met the pre-specified equivalence criteria for biosimilarity. Trial data demonstrates subtle differences in clinical outcomes and adverse events between the biosimilars and the reference product (RP). The development of etanercept biosimilars may reduce the financial burden of treating RA, but real-world data regarding efficacy and safety in comparison to the RP will be vital to assess for meaningful differences.