133 patients with IBD (105 with CD and 28 UC) on maintenance biosimilar switched to different biosimilar16  • No significant difference between clinical disease scores in switched patients from baseline compared to weeks 16/18 after switch • No significant difference in drug persistence compared to the historical cohort. 221 patients (179 CD and 42 UC) switched between biosimilars17  • Increase in drug trough level following switch • No difference in CRP and no new antidrug antibodies detected. The gene discussed is CRP; the disease is inflammatory bowel disease.