Comparison of Trough Level- and Clinical-based Spacing of Infliximab Infusions in Patients With IBD in Deep Remission

Inclusion Criteria: * Age greater than 18 years * Patients with a diagnosis of Crohn's disease or ulcerative colitis according to clinical, biological, morphological and endoscopic criteria defined by the ECCO guidelines22, 23 * Patients in deep remission since at least 6 months17: * CDAI \< 150 for CD, Partial Mayo score \< 3 for UC * CRP (C reactive protein) \< 10 mg/l * CDEIS \< 6 (\<3 in each segment) for CD, Mayo endoscopic subscore of 0 or 1 for UC * For CD patients with small bowel disease: No ulceration on MRI, only asymptomatic fibrotic stenosis without inflammation and retro dilatation. No ulceration on wireless capsule endoscopy if feasible * For patients with perianal disease: No active draining fistula, or perianal abscess on clinical exam and MRI * Treatment with infliximab at stable dose (5mg/kg) with a stable interval for at least 4 months * Infliximab trough level \> 3 ug/ml * No change in other IBD therapies in the past 4 months * Signed informed consent form * Subjects must be able to attend all scheduled visits and to comply with all trial procedures * Subjects must be covered by public health insurance Exclusion Criteria: * Subject unable to read or/and write * Planned longer stay outside the region that prevents compliance with the visit plan * Subject who are in a dependency or employment with the sponsor or the investigator * Participation in another clinical trial or administration of an unapproved drug …