Evolution after switching to biosimilar infliximab in inflammatory bowel disease patients in clinical remission

The biosimilar of infliximab (CT-P13) has been approved for the same indications held by the infliximab reference product (Remicade^®); however, there are few clinical data on switching in inflammatory bowel disease (IBD). The aim of this study was to assess the efficacy, safety, bioavailability profile and factors associated with relapse after switching to biosimilar infliximab in IBD patients in clinical remission.

Observational study with IBD patients treated with Remicade^® for at least 6 months and in clinical remission for at least 3 months who switched to infliximab biosimilar. The incidence of relapse, adverse effects and possible changes in drug bioavailability (trough level and antidrug antibodies) were evaluated.

Thirty six patients were included (63.9% CD) with a mean follow-up of 8.4 months (SD±3.5). The 13.9% had clinical relapse. The longer clinical remission time before switching (HR=0.54, 95% CI=0.29-0.98, P=.04) and detectable infliximab levels at the time of switching (HR=0.03, 95% CI=0.001-0.89, P=.04) were associated with a lower risk of relapse. No differences were found between infliximab levels at the time of switching and at weeks 8 and 16 (P=.94); 8.3% of the patients had some adverse event, requiring the suspension of biosimilar in one patient for severe pneumonia.

Switching to biosimilar infliximab in a real-life cohort of IBD patients in clinical remission did not have a significant impact on short-term clinical outcomes. The factors associated with relapse were similar to those expected in patients continuing with Remicade^®.