Switching from infliximab originator to a first biosimilar is safe and effective. Results of a case-control study with drug levels and antibodies evaluation.

Background: Inflammatory bowel disease is treated with anti-TNF agents such as infliximab and its biosimilars, but use of biosimilars is limited due to perceived risks of adverse events.
Aim: To explore safety and effectiveness of switching from the infliximab originator to a first biosimilar.
Patients and Methods: Clinical and biological outcomes were compared between 53 patients who switched from the infliximab originator to the biosimilar CT-P13 (Switched group) and 13 patients treated with CT-P13 from the beginning (Naïve group). Infliximab trough levels and antidrug antibodies were measured.
Results: At enrolment, patients in the Switched group had a longer median duration of infliximab treatment than Naïve (4.0 vs. 0.6 years, p < 0.0001) but similar proportions of patients were in remission (77% and 62%, respectively). Infliximab discontinuation due to adverse events or loss of efficacy was less common in the Switched (26%) than Naïve group (62%, p = 0.017). Variables independently associated with time to discontinuation were disease activity (p < 0.0001) and immunomodulating treatment (p = 0.019) at enrolment. Trough levels and antidrug antibodies were similar between groups during observation.
Conclusion: This study confirms that switching from infliximab originator to a first biosimilar is safe and effective. Patients at highest risk of losing treatment efficacy are those with active disease, irrespective of the therapeutic switch.
(Copyright © 2019 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)