The use of infliximab biosimilar CT-P13 has increased in patients with inflammatory bowel disease. Nevertheless, doubts about switching from infliximab originator to biosimilar still exist among patients and health care professionals.
Our tertiary referral center underwent a mandatory switch from infliximab originator to CT-P13 in 2017. We investigated pharmacokinetics, efficacy, and safety of this switch. The primary endpoint was infliximab discontinuation within 6 months of switching. Secondary endpoints included loss of clinical remission, need for treatment optimization, adverse events, evolution of patient-reported outcome, C-reactive protein, infliximab trough levels, and antidrug-antibodies.
A total of 361 patients (54.0% male, 70.0% Crohn's disease, 55.6% in clinical remission) were enrolled. Infliximab discontinuation within 6 months was observed in 4%. Loss of clinical remission, adverse events, and antidrug-antibodies were identified in only 2.0%, 2.2%, and 1.1% of patients, respectively. C-reactive protein concentrations and infliximab trough levels remained stable. Independent factors associated with remission at 6 months were lower PRO2 at switch (HR 6.024; 95% CI, 4.878-8.000; P < 0.0001) and higher hemoglobin levels (HR 1.383; 95% CI, 1.044-2.299; P = 0.018).
Switching from infliximab originator to CT-P13 was not associated with an increased risk of treatment discontinuation, loss of clinical remission, or adverse events. No significant changes in infliximab trough levels or immunogenicity could be identified.