Switching from originator infliximab to biosimilar versus continuing on originator in inflammatory bowel disease: results from the observational Project NORTH study.

OBJECTIVE: Project NORTH compared real-world clinical and economic outcomes in Swedish patients with inflammatory bowel disease (IBD) who switched from originator infliximab to its biosimilar.

MATERIALS AND METHODS: Data from electronic medical records and Swedish national registries were linked. Switchers (patients switching from originator infliximab to its biosimilar between 1 April 2014, and 31 December 2017) and non-switchers (patients who received originator infliximab and did not switch to a biosimilar by 31 December 2017) were followed up until 31 October 2019.

RESULTS: Baseline concomitant medication use, disease duration, and inflammatory markers were lower among switchers than non-switchers. At 6 months, the proportion of patients with stable disease was higher among switchers than non-switchers (71/109 [65%] vs 54/107 [50%]; p  = .0385); differences were not significant in subsequent follow-ups. At 6 and 24 months, 98% and 93% of switchers, respectively, used concomitant medications versus 96% and 79% of non-switchers. Throughout the study, all-cause treatment discontinuation occurred in 74 (67%) switchers and 105 (95%) non-switchers. At 36-months, mean (SD) number of IBD-related in-patient care days was higher among non-switchers (2.95 [4.71]) than switchers (1.40 [4.20]), as were total medical costs (€16,740 vs €3,872).

CONCLUSIONS: No substantial differences in clinical outcomes or healthcare resource utilization were observed between switchers and non-switchers. Several analyses indicate that non-switchers might have more poorly controlled/severe disease than switchers at baseline. Overall, numerous difficulties might arise when executing a high-quality, real-world study, including possible selection bias for patients with better disease control for NMS, limiting the generalizability of the results.