NON-MEDICAL SWITCHING FROM INFLIXIMAB TO A BIOSIMILAR IN ADOLESCENTS AND YOUNG ADULTS WITH INFLAMMATORY BOWEL DISEASE

Abstract
Studies in adults with inflammatory bowel disease (IBD) have demonstrated that a one-time switch from the originator to a biosimilar has not resulted in loss of response, increased side effects, or antibody development. Data describing non-medical switching is limited in adolescents and young adults. The objective of this study was to evaluate clinical outcomes of one-time switches from the originator to a biosimilar in adolescents and young adults with IBD. Patients with IBD that underwent a non-medical switch from infliximab originator to a biosimilar were retrospectively reviewed. Demographic data, physician global assessments (PGA), and laboratory values (albumin, hemoglobin, sedimentation rate (ESR), c-reactive protein (CRP), anti-TNF level, and anti-TNF antibody level) were recorded up to one year prior to the switch and up to one year after the switch. Rates of continuation on the biosimilar was reported at 6 and 12 months post-switch. Linear mixed effect models with random intercepts accounting for within patient correlation were used to compare continuous lab values before and after switching. A total of 53 patients completed a switch from infliximab originator to a biosimilar. The mean age at the time of the switch was 18 (+/- 2.86) years old. Fifty-three percent of those undergoing a switch were female, 74% had Crohn’s disease, and 96% were switched to the biosimilar infliximab-dyyb. At the time of the switch, 52 (98%) patients had quiescent disease activity based on PGA and 1 (2%) patient had mild disease. At follow up after receiving at least 2 biosimilar infusions, 51 (96%) patients had quiescent disease and 2 (4%) patients had mild disease based on the PGA. At 6 months post switch, 48 (90%) patients were still on the biosimilar. Three (6%) patients switched back to the originator due to worsening symptoms, one (2%) patient developed worsening psoriasis, and one (2%) patient had ongoing issues with IV access. Of the 33 patients who had a full 12 months of follow-up data, 91% (30/33) remained on the biosimilar, one patient switched back to the originator due to worsening symptoms, and two switched to adalimumab due to the development of psoriasis and an underlying social situation, respectively. There was no statistically significant difference in albumin, hemoglobin, ESR, CRP, or anti-TNF levels when comparing pre- and post- switch values. The mean anti-TNF level prior to the switch was 17.3 ug/ml (95% CI: 13.7 -19.0) and 15.1 ug/ml (95% CI: 12.5 - 17.8) after the switch. No patients developed anti-drug antibodies or infusion reactions. A one-time non-medical switch to an infliximab biosimilar in an adolescent and young adult cohort had no significant effect on clinical remission rates, laboratory markers of inflammation, serious adverse events, anti-TNF levels, or anti-drug antibodies.