Résumé : Background: Infliximab (IFX) is efficacious in inducing remission in severe forms of pediatric Crohn's disease (CD). Adult studies indicate that IFX is also safe and well tolerated as maintenance therapy. The present study aimed to evaluate in a prospective manner the efficacy and safety of IFX as maintenance therapy of severe pediatric CD comparing scheduled and "on demand" treatment strategies. Methods: Forty children with CD (nonpenetrating, nonstricturing as well as penetrating forms, mean age: 13.9 ± 2.2 years) with a severe flare-up (Harvey-Bradshaw Index [HBI] ≥ 5, erythrocyte sedimentation rate [ESR] > 20 mm/h) despite well-conducted immunomodulator therapy (n = 36 azathioprine, n = 1 mercaptopurine, n = 3 methotrexate) combined with steroids were included in this randomized, multicenter, open-label study. Three IFX infusions (5 mg/kg) were administered at week (W)0/W2/ W6. At W10, clinical remission (HBI < 5) and steroid withdrawal were analyzed and IFX responders were randomized to maintenance therapy over 1 year: group A, scheduled every 2 months; group B, "on demand" on relapse. Results: In all, 34/40 children came into remission during IFX induction therapy (HBI: 6.7 ± 2.5 (WO) vs. 1.1 ± 1.5 (W10); P < 0.001). At the end of phase 2, 15/18 (83%) patients were in remission in group A compared to 8/13 (61%) children in group B (P < 0.01), with a mean HBI of 0.5 versus 3.2 points (group A versus B, P = 0.011). In group A, 3/13 (23.1%) children experienced a relapse compared to 11/12 (92%) children in group B. No severe adverse event occurred during this trial. Conclusions: IFX is well tolerated and safe as maintenance therapy for pediatric CD, with a clear advantage when used on a scheduled 2-month basis compared to an "on demand" basis. Copyright © 2008 Crohn's & Colitis Foundation of America, Inc.