Abstract
As of 31 December, 2023, 31 observational studies have been published, including a total of 6081 patients who underwent a switch from one biosimilar to another biosimilar of the same reference biologic. Most studies evaluated infliximab, while a smaller number evaluated adalimumab, rituximab or etanercept. Indications studied now include sarcoidosis, as well as the indications previously reported of rheumatoid arthritis, psoriatic arthritis, axial spondyloarthritis/ankylosing spondylitis and inflammatory bowel disease (Crohn's disease and ulcerative colitis). This updated data set includes eight additional studies and 2386 more patients compared with those included in an earlier systematic review of biosimilar-to-biosimilar switching. In addition, since the earlier systematic review was published in 2022, the European Medicines Agency has stated that reference-to-biosimilar and biosimilar-to-biosimilar switching in the European Union is safe and efficacy remains unchanged after switching. Furthermore, following a review of the available evidence, the US Food and Drug Administration has confirmed that initial safety and immunogenicity concerns related to biosimilar switching are unfounded and that no differences are observed in efficacy, safety or immunogenicity following one or more switches. The availability of this new efficacy and safety data together with the supportive statements from the European Medicines Agency and the Food and Drug Administration re-confirm the conclusion that as a scientific matter, biosimilar-to-biosimilar switching is an effective clinical practice, with no new safety concerns. Any suggestions to the contrary are not supported by the evidence.