Post-Marketing Pooled Safety Analysis for CT-P13 Treatment of Patients with Immune-Mediated Inflammatory Diseases in Observational Cohort Studies

Background At EU marketing authorisation, safety data for CT-P13 (biosimilar infliximab) were limited, particularly in some indications, and uncommon adverse events (AEs) could not be evaluated among relatively small analysis populations. Objectives Our objective was to investigate the overall safety profile and incidence rate of AEs of special interest (AESIs), including serious infections and tuberculosis, in CT-P13-treated patients. Methods Data were pooled from six observational studies representing authorised indications of CT-P13 (ankylosing spondylitis, rheumatoid arthritis, psoriatic arthritis, plaque psoriasis, adult and paediatric Crohn's disease and ulcerative colitis). Patients were analysed by indication and treatment (patients who received CT-P13 or those who switched from reference infliximab to CT-P13 <= 6 months prior to enrolment or during the study). Results Overall, 4393 patients were included (n = 3677 CT-P13 group; n = 716 switched group); 64.03% of patients had inflammatory bowel disease and 6.31% of patients were antidrug antibody positive. Overall, 32.94% and 9.58% of patients experienced treatment-emergent AEs (TEAEs) and treatment-emergent serious AEs, respectively. Across indications, TEAEs were more frequent with CT-P13 than with the switched group. Infections including tuberculosis were the most frequent serious AESI overall (2.48%) and by treatment group or indication. In total, 14 patients (0.32%) reported active tuberculosis. Overall incidence rates per 100 patient-years (95% confidence interval) were 3.40 (2.788-4.096) for serious infections including tuberculosis and 0.44 (0.238-0.732) for active tuberculosis. Infusion-related reactions were the second most frequent AESI following infection including tuberculosis. Conclusion The CT-P13 safety profile appears consistent with previous studies for CT-P13 and reference infliximab, supporting the favourable risk/benefit balance for CT-P13 treatment.