LAUSR

OBJECTIVES Infliximab (IFX) is commonly used to treat children with inflammatory bowel disease (IBD). We previously reported that patients with extensive disease started on IFX at a dose of 10mg/kg had greater treatment durability at year one. The aim of this follow-up study is to assess the long-term safety and durability of this dosing strategy in pediatric IBD. METHODS We performed a retrospective single-center study of pediatric IBD patients started on infliximab over a 10-year period. RESULTS 291 patients were included (mean age = 12.61, 38% female) with a follow-up range of 0.1 to 9.7 years from IFX induction. 155 (53%) were started at a dose of 10mg/kg. Only 35 patients (12%) discontinued IFX. The median duration of treatment was 2.9 years. Patients with UC (p=<0.01) and patients with extensive disease (p=0.01) had lower durability, despite a higher starting dose of infliximab (p=0.03). Adverse events (AEs) were observed to occur at a rate of 234 per 1,000 patient-years. Patients with a higher serum infliximab trough level (≥ 20 µg/ml) had a higher rate of AEs (p=0.01). Use of combination therapy had no impact on risk of AEs (p=0.78). CONCLUSIONS We observed an excellent IFX treatment durability, with only 12% of patients discontinuing therapy over the observed timeframe. The overall rate of AEs was low, the majority being infusion reactions and dermatologic conditions. Higher infliximab dose and serum trough level> 20ug/ml were associated with higher risk of AEs, the majority being mild and not resulting in cessation of therapy.