Durability of Infliximab Is Associated With Disease Extent in Children With Inflammatory Bowel Disease.

Objectives: The aim of the study was to evaluate infliximab (IFX) dosing and treatment durability relative to luminal disease burden in patients with inflammatory bowel disease.

Methods: Records from 98 pediatric patients treated with IFX between 2012 and 2014 were reviewed. Disease extent was classified as "limited," "moderate," or "extensive" based on cumulative assessment of mucosal involvement. Patients started taking standard 5 mg/kg dosing were compared with those initiated taking 10 mg/kg with regard to treatment durability.

Results: Overall, 26.4%, 58.3%, and 70% with limited, moderate, or extensive disease, respectively, started taking a standard IFX dose of 5 mg/kg required therapy escalation. Patients with moderate and extensive disease, started taking the 5 mg/kg per dose, showed statistically significant shorter times to escalation than those with limited disease. The percentage of patients remaining on their initial 5 mg/kg per dose at 12 months was 80.1%, 56.9%, and 40.0% for limited, moderate, and extensive disease, respectively. Among patients started taking 10 mg/kg, 100% remained on this dose. All the patients with limited disease who required dose escalation continued on the higher dose at the time of analysis; however, among those with the most extensive disease, 43% failed escalation because of nonresponse or infusion reaction.

Conclusions: Patients with extensive disease started taking 5 mg/kg of IFX were more likely to require dose escalation compared to those with limited or moderate disease. All of the patients with moderate and extensive disease started taking 10 mg/kg of IFX remained on this dose. These results suggest that patients with more extensive disease may benefit from higher initial IFX dosing as it relates to durability of the treatment.