Ten adalimumab biosimilars have been introduced in the United States (USA) since 2023, while adalimumab biosimilars have been available for several years in other countries. These experiences of biosimilar uptake outside the USA can inform US-based healthcare professionals on switching in real-life practice settings. Considerations include how healthcare professionals might meaningfully address patient concerns about outcomes to improve patient satisfaction. A search of the MEDLINE database was used to identify publications on switching to and among adalimumab biosimilars in an ex-US setting, with no restriction on publication language and using a time frame of 1 January 2017 through 12 December 2023, coinciding with the European Union approval of the first adalimumab biosimilar, adalimumab-atto, in March 2017. This narrative review aims to provide insights into the efficacy and safety of transitioning to and among adalimumab biosimilars in adult patients from clinical studies but also, more importantly, using real-world evidence (RWE) from outside the USA. Overall, RWE suggested that efficacy and outcomes were consistent in patients who underwent switching from the reference product (RP) across various immune-mediated inflammatory diseases when compared to patients who did not switch from the RP. The ex-US RWE of RP and biosimilar adalimumab switches generally reflected the experiences observed in clinical trials; however, RWE findings elucidated several challenges to biosimilar uptake, including patient education, provider training, and supportive policies.
