A 24-month Real Life PErsistence Efficacy and Safety Study in IBD Patients in REMission Switched From Intravenous Infliximab to Subcutaneous Infliximab CT-P13 Remsima®SC

Descriptive: A 24-month multicentre, observational, prospective cohort study. Population: IBD Patients under stable clinical and biological remission Study treatments: Patients who will be proposed to switch, or who have just switched, from the intravenous originator Remicade® or one of its biosimilars to the subcutaneous infliximab Remsima®SC as part of routine care. All consecutive patients in IBD centers participating in the study will be proposed to participate in the study during their regular outpatients' visits. Objectives:The primary objective of PEREM study is to determine the rate of persistence of subcutaneous infliximab at 48 weeks after switching from IV infliximab to subcutaneous infliximab Remsima®SC.

Number of patients: 400 patients in approximatively 40 sites in France Recrutment period: The trial duration for each patient will be 2 years Main Endpoint:The primary endpoint is to assess the rate of persistence of subcutaneous infliximab at month 12 after switching from IV infliximab to SC infliximab Remsima®SC. Secondary Endpoint: * Percentage of patients on steroid free clinical remission at week 96 after switch. Steroid-free Clinical Remission (CR) is defined as a Harvey Bradshaw Index (HBI) score≤4 CD patients and a Partial Mayo Score (PMS) ≤2 with each sub-score of 1 or less for UC. When HBI scoring will be infeasible (stoma, pouch), evaluation of clinical remission will be estimated by stoma emptying count and/or by the physician global assessment (Sturm 2019) Patients having discontinued subcutaneous infliximab Remsima®SC therapy whatever the reason during the 24 months of follow-up as well as patients referred to disease-related surgery and patients lost to follow-up before month 24 will be considered as failure to subcutaneous infliximab Remsima®SC therapy (intention to treat analysis) and will be classified in the group of patients having failed to maintain steroid free clinical remission under infliximab Remsima®SC during the whole study period. * Percentage of patient Reported Outcomes PRO2 rates at inclusion, months 3, 6, 12 and 24 * Percentage of biological remission rates (FC \<250 μg/g, CRP \<5 mg/L) at inclusion, month 3, 6, 12 and 24. * Percentage of clinical relapse free rates at inclusion, month 3, 6, 12 and 24 * Percentage of loss of response rates at inclusion, month 3, 6, 12 and 24 * Percentage of clinical response and remission at inclusion, month 3, 6, 12 and 24 * Mean change from baseline in HBI or PMS, and mean change from baseline in CRP and fecal calprotectin * Proportion of patients with positive antibodies (IFX, ANA) comparing therapy with intravenous or one of its biosimilars original and subcutaneous infliximab Remsima®SC * Measure adherence to subcutaneous infliximab Remsima® switch based on pharmacy data during the follow-up with Medication Possession Ratio (MPR ). * Twelve-month cumulative surgery rates * Hospitalization rate at month 24 * Cumulative infection rate at month 24 * Cumulative SC reactions at month 24 * Discontinuation of subcutaneous infliximab therapy cumulative rates at month 24 * Incidence of specific anti-drug antibodies detected during the study