Outcomes of Patients With Inflammatory Bowel Diseases Switched From Maintenance Therapy With a Biosimilar to Remicade.

Background & Aims: There is evidence that it is safe and effective for patients with inflammatory bowel diseases (IBD) to switch from maintenance therapy with an original infliximab drug to a biosimilar, but little is known about outcomes of reverse switches and/or multiple switches. We aimed to evaluate the effects of a reverse switch (from a biosimilar to Remicade) in a real-life cohort.

Methods: We performed a prospective observational study of 174 unselected and consecutive patients with IBD (136 with Crohn's disease [CD] and 38 with ulcerative colitis [UC]) who received maintenance therapy with the biosimilar in Hungary. In September 2017, patients were switched from the biosimilar (CT-P13) to Remicade, due to reimbursement policies. In our cohort, 8% (n = 14) patients had been previously exposed to the originator Remicade. We collected clinical and biochemical information from patients at baseline (time of the switch) and 16 and 24 weeks thereafter. Clinical remission was defined as a Crohn's disease activity index <150 points or no fistula drainage, or a partial Mayo score <3 points for patients with UC. Serum drug trough levels and anti-drug antibodies were measured at baseline and week 16.

Results: There was no significant difference in the proportion of patients in clinical remission at week 8 before the switch (82.5% with CD and 82.9% with UC), at baseline (80.6% with CD and 81.6% with UC), at week 16 (77.5% with CD and 83.7% with UC), or at week 24 (CD 76.3% with CD and 84.9% with UC) (P = .60 among groups for patients with CD and P = .98 among groups for patients with UC). For all patients, mean serum trough levels of infliximab were 5.33 ± 4.70 μg/mL at baseline and 5.69 ± 4.94 μg/mL at week 16 (P = .71); we did not find significant differences in prevalence of anti-drug antibody at baseline (16.2%) compared with week 16 (16.9%) (P = .87). Four infusion reactions occurred, until week 24 of follow up. There was no difference in outcomes or trough or antidrug antibody levels between patients with or without previous exposure to Remicade.

Conclusions: We collected data from a real-life cohort of patients with CD or UC who were switched from maintenance therapy with a biosimilar to Remicade or were treated with only Remicade. No significant changes were observed in remission, trough levels, or antidrug antibodies in patients switched from the biosimilar to Remicade. No new safety signals were detected.