Supplementary Material for: Low Discontinuation Rate of Infliximab Treatment in Steroid-Dependent/Refractory Crohn’s Disease Patients

Background: Many patients with moderate to severe Crohn’s disease (CD) are treated with infliximab (IFX). As most of these patients experience a long-lasting therapy, the outcome and withdrawal of IFX treatment are important clinical questions. Methods: In this retrospective study, we analyzed the treatment outcome in moderate to severe CD patients with a steroid-dependent/refractory disease course started on IFX. Withdrawal of IFX was evaluated in patients with deep remission defined as clinical (Harvey-Bradshaw Index ≤4), biochemical (fecal calprotectin [FC] ≤150 μg/g stool) over a period of 2 years, and endoscopic and histological remission before discontinuation of IFX. Results: After induction with IFX, clinical remission was observed in 45/109 patients (41.3%) and clinical response in 61/109 patients (56.0%). Only 8/109 patients (7.3%) achieved deep remission and therefore could be discontinued from IFX therapy. In 4 of these patients (50%), relapse was observed after discontinuation of IFX treatment. FC decreased in these 8 patients in deep remission from 652 ± 168 μg/g stool (mean ± SE) at baseline to 24.9 ± 8.1 μg/g stool at 14 weeks. When compared to patients in deep remission, FC had decreased significantly less at 14 weeks in patients in clinical remission after induction with IFX (n = 31; 154 ± 55 μg/g stool; p = 0.01), in patients with clinical response after induction achieving clinical remission during the maintenance phase (n = 11; 352 ± 67 μg/g stool; p = 0.004), or in patients with chronic active disease course on maintenance therapy (n = 50; 645 ± 93 μg/g stool; p < 0.001). Conclusion: A low discontinuation rate was observed for steroid-dependent/refractory moderate to severe CD patients with IFX treatment. As FC showed a more or less pronounced decrease depending on the response to the IFX treatment, monitoring of FC may become a noninvasive tool for tailoring biological therapy in CD patients.