Biosimilar versions of widely prescribed drugs, including the tumour-necrosis factor antagonist infliximab, are becoming increasingly available. As biosimilars are not identical copies of reference products, evidence may be required to demonstrate that switching between a reference biologic and biosimilars is safe and efficacious. To establish interchangeability, US Food and Drug Administration guidance states that studies must demonstrate that biosimilars remain equivalent or non-inferior to a reference product after multiple switches between products.
To investigate the evidence evaluating the safety and efficacy of switching between reference and biosimilar infliximab in patients with inflammatory disorders, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis.
Published studies presenting data on switching between reference and biosimilar infliximab were identified by searching the MEDLINE database. Congress abstracts were identified by searching the EMBASE database and manually searching abstracts from relevant congresses.
A total of 113 journal articles and 149 abstracts were found. Of these, 70 were considered relevant and included in this analysis. Most of the publications were uncontrolled, observational studies. Data from six randomised, controlled trials were identified. In general, the evidence revealed no clinically important efficacy or safety signals associated with switching.
While available data have not identified significant risks associated with a single switch between reference and biosimilar infliximab, the studies available currently report on only single switches and were mostly observational studies lacking control arms. Additional data are needed to explore potential switching risks in various populations and scenarios.