S82 The Significance of the Concentration of Antibodies to Infliximab When Alternating the Original Drug Infliximab and Its Biosimilar

Abstract

Background: Biosimilars are analogues of biopharmaceutical drugs, with a close, but not identical, parent molecule. Biosimilars offer greater access to affordable treatment for inflammatory bowel disease, while being comparable in efficacy and safety to brand-name products. However, switching from original genetically engineered biological drugs (GEBD) to biosimilars requires study and analysis. We aimed to determine the concentration of antibodies to infliximab in patients with UC receiving infliximab by one trade name (TN) and when alternating infliximab and its biosimilars and to determine the frequency of loss of response during the year of observation. Methods: In the Department of inflammatory bowel diseases of the A. S. Loginov Moscow Clinical Scientific Center of the Moscow Healthcare Department, were observed 38 patients with IBD, who regularly received the original drug infliximab (IFL) -group 1 (n = 20), group 2 a group of patients (n = 18) alternated the original drug infliximab and its biosimilar. The level of antibodies to IFL in the blood serum before the next scheduled administration of the drug 10 months after inclusion in the study by enzyme immunoassay using the Shikari Quantitative Determination of Infliximab (Q-INFLIXI) and Shikari Quantitative Determination of Antibodies to Infliximab (Q-ATI) kits (Matriks Biotek). The loss of response was assessed by clinical, laboratory and instrumental data. Comparative analysis was carried out by the method of 4-field tables using non-parametric statistical tests. Results: Of the 20 patients with UC of the 1st group, 3 (15.0%) had antibodies to IFL, on average, its concentration was 8.5 ± 2.2 ng/ml (normal values <5 ng/ml). Of the 18 patients of the 2nd group 10 (55.5%) antibodies to IFL were detected, on average - 187.9 ± 38.2 ng/ml. (OR - 0.141; 95% CI 0.030-0.658; x2 - 6.923, P = 0.023). During the year of observation among patients of the 1st group receiving the original IFL, the loss of response occurred in 2 (10.0%) patients with UC. Of the patients of the 2nd group, the loss of response occurred in 8 (10.0%) (RR - 0.139; 95% CI 0.025 - 0.785; x2 - 5.797; p = 0.017). Conclusion(s): The concentration of antibodies to infliximab is higher in patients with UC when alternating IFL and its biosimilars than in patients with UC who regularly receive IFL by one TN. The frequency of loss of response when alternating infliximab and its biosimilars is significantly higher in patients with UC who regularly receive the drug for one TN.