P657 Persistence of subcutaneous infliximab after two years of the switch from intravenous infliximab to subcutaneous infliximab in Inflammatory Bowel Disease patients

Abstract

Abstract Background Biosimilar infliximab (CT-P13) has been available for subcutaneous (SC IFX) administration since march 2021. It has shown to be equivalent to its every-8-week-intravenous formula (IV IFX), however, we do not have long term efficacy and safety data. Our aim was to evaluate medication persistence, efficacy and safety two years after switching from IFX IV to IFX SC Methods Multicentre, descriptive, and observational study, with prospective data collection, of Crohn’s Disease (CD) or Ulcerative Colitis (UC) patients who were going to be changed from IV IFX to SC IFX. All patients were on clinical and biological remission for at least 6 months. Clinical activity, analytical data, trough level determinations and adverse events were gathered. Baseline results were compared with those from week 108 after starting CT-P13 SC. Maintenance of the drug after two years and the reason for removal, if so, or of loss of follow-up, were evaluated. Results 41 patients were included. 24 of whom had intensified doses while 17 were on standard doses (5 mg/kg every 8 weeks). 51% were male; mean age 40.8. 63,4 % (n = 26) had CD. No PCR differences were observed at baseline (IV IFX) [median 0,17 mg/dL] and week 108 [median0,3 mg/dL]. Fecal calprotectin stayed under 200 ug/mg from baseline to 24 months. No changes in clinical indexes were observed. A considerable increase in drug levels was observed after switching to SC IFX at week 108 (6,8 vs 12.3; p < 0,001). 46% of the patients were also on immunosupressor when they switched to IFX SC, and 52% of these had removed it after 2 years of IFX SC. 85% of the patients were still on IFX SC after two years (only one was removed due to loss of response). There were only 3 adverse events, all of which were mild. Conclusion Persistence of IFX SC after two years was observed in 85% of the patients. Switching from IV IFX to SC IFX maintains remission in Inflammatory Bowel Disease (IBD) after a 2-year follow-up. Higher drug levels are obtained with the subcutaneous formulation, despite removing the immunosupressor in over 50% of the patients. Switching from IV IFX to SC IFX is safe in IBD.