Long-term follow up after switching from original infliximab to an infliximab biosimilar: real-world data

Background: Several studies have reported positive efficacy outcomes for patients with inflammatory bowel disease treated with CT-P13, an infliximab biosimilar. Data from followup periods longer than 1 year are still scarce. Here, we assessed the long-term efficacy data, loss of response and safety after switching from infliximab to CT-P13 in patients with inflammatory bowel disease. Methods: This was a prospective single-center observational study involving patients with moderate-to-severe Crohn's disease and ulcerative colitis switched from infliximab to CT-P13 treatment and reviewed up to 24months. Efficacy and loss of response were measured using the Harvey–Bradshaw (HB) index and partial Mayo score for patients with Crohn's disease and ulcerative colitis respectively. C-reactive protein, infliximab drug levels, adverse events and antidrug antibodies were also monitored throughout the study. Results: A total of 64 patients with Crohn's disease and 36 patients with ulcerative colitis were included. Most of them (72%) remained on CT-P13. Overall, 28% of patients discontinued the therapy due to loss of response, adverse events or long-lasting clinical remission. Remission at 18 and 24months occurred in 69.9% and 68.5% of patients, respectively. Dose increase was performed in 22% of patients, with remission being reached in 60% of them. HB index, partial Mayo score, C-reactive protein and infliximab drug levels did not show significant changes. Serious adverse events were reported in 14% of patients. Overall, two patients developed low levels of antidrug antibodies. Conclusions: Most of the patients switching from original infliximab were maintained on CTP13 at 2years of follow up with a good profile of efficacy and safety.