Background: Biosimilar-infliximab (CT-P13) was approved for all indications as an originator-infliximab although the clinical efficacy was only demonstrated in rheumatoid arthritis and ankylosing spondylitis. The objective of this study was to evaluate the clinical efficacy and effectiveness of biosimilar-infliximab in the maintenance treatment of inflammatory bowel diseases (IBDs).
Methods: We conducted an observational, prospective single-center study of the IBD patients receiving infliximab (IFX) maintenance treatment. All IBD patients on IFX maintenance treatment were systematically switched from originator-IFX to biosimilar-IFX. The health-related quality of life (HRQoL) measures used in this survey were a disease-specific Inflammatory Bowel Disease Questionnaire (IBDQ) and a generic 15D instrument. Patient reported outcomes were collected at three IFX administration visits at clinic: 8 weeks before the switching (the last originator-IFX infusion), at the time of switching (the first biosimilar-IFX infusion) and 16 weeks after the switching (the third biosimilar-IFX infusion). Clinical disease activity (Harvey-Bradshaw Index (HBI) or partial Mayo score) was collected from patients' records. The primary endpoints of the study were the changes in HRQoL and clinical disease activity before and after the switching.
Results: In the study, 56 patients (30 male and 26 female) were included: 24 patients diagnosed with Crohn's disease, 29 with ulcerative colitis and 3 as IBD unclassified. The patients' ages varied from 20 to 74 (mean 35.82, SD 11.51). Seven patients were smoker, 13 patients were former smoker and 36 patients never smoked. The duration of the treatment with originator-IFX ranged from 3 months to 11 years (mean 3.3 years, SD 2.91). The median IBDQ score was 189 (SD 29.006) 8 weeks before the switching, 186 (SD 31.789) at the time of switching, and 192 (SD 29.340) 16 weeks after the switching. Respective median 15D scores were 0.915 (SD 0.067), 0.909 (SD 0.072), and 0.913 (SD 0.080). Before the last originator-IFX infusion the mean HBI was 1.80 (SD 3.34) and the mean partial Mayo score 0.95 (SD 1.69), whereas the mean HBI was 1.93 (SD 3.71) and the mean partial Mayo score 0.60 (SD 1.05) before the third biosimilar-IFX infusion. No statistically significant difference was observed between IBDQ (p=0.300), 15D (p=0.700), HBI (p=0.317), and the partial Mayo scores (p=0.481) before and after the switching. No serious adverse events were observed during the follow-up.
Conclusions: These early data suggested that in maintenance treatment of IBDs biosimilar-IFX was, in light of IBDQ, 15D, HBI, and the partial Mayo scores, comparable to originator-IFX during the first 16 weeks after the switching.