Effects of successive switches to different biosimilars infliximab on immunogenicity in chronic inflammatory diseases in daily clinical practice.

Objective: To evaluatre the risk of immunogenicity in patients with chronic inflammatory diseases who experienced successive non-medical swiches to different biosimilars infliximab.

Patients And Methods: Observational study over a 3-year observation period assessing the risk of immunogenicity in i) patients in maintenance therapy with innovator infliximab who were successively switched to CT-P13, then to SB2 (cohort-1) and ii) biologic-naive patients initiated with CT-P13 before being switched to SB2 (cohort-2). A propotion meta-analysis was also performed, integrating our results to 16 additional studies.

Results: Cohort-1 included 265 patients who switched to CT-P13, and 140 patients were subsequently switched to SB2. Among the 235 anti-drug antibody (ADA)-free patients at baseline, 20 patients (8.5%) developed ADA over the 3-year observation period (rate of 3 for 100 patient years). Cohort-2 included 44 patients, of whom 29 subsequently switched to SB2. A total of 11 patients (25%) developed ADA within 3 years (rate of 14 for 100 patients years). We found no influence of the number of biosimilars infliximab received on ADA deveopment in both cohorts. The risk of treatment discontinuation was significantly higher in patients with positive ADA in both cohorts. The meta-analysis including our data exposed an incidence of immunogenicity of 4.7% (95% CI 3.5-6.1%) after the switch from innovator infliximab to biosimilar infliximab and 21.1% (95% CI 13.1-30.3%) in patients initiating biosimilar infliximab.

Conclusion: Immunogenicity was not favored by successive non-medical switches to biosimilars infliximab in our study, but was associated with treatment discontinuation.