Safety and efficacy of weekly adalimumab 80 mg therapy in pediatric Crohn's disease

Adalimumab is commonly used to induce and maintain remission in pediatric Crohn's disease (CD). However, data on the efficacy and safety of high-dose adalimumab in this population are limited. This study aimed to evaluate the therapeutic effectiveness and safety of weekly high-dose adalimumab (80 mg) in pediatric CD patients.

This multicenter retrospective study included pediatric patients with CD who received adalimumab 80 mg weekly for more than 30 days following suboptimal response to standard dosing between 2014 and 2023. Clinical and biochemical outcomes, treatment durability, and adverse events (AEs) were assessed at predefined time points. Regression analyses were used to explore predictors of sustained corticosteroid-free remission (SCFR) and clinical response.

Thirty-eight patients (71% male; median age 16.3 years [interquartile range, IQR: 14.3-16.9]) underwent dose intensification. Ileocolonic CD was observed in 53%, and 29% had perianal disease. Clinical remission at 12 months was achieved in 50% of patients. Among the 27 patients (71%) with available adalimumab trough concentrations (ATC), 74% reached a therapeutic level (≥7.5 µg/mL) at 1 year. No significant predictors of SCFR or clinical response were identified. Early post-intensification drug levels predicted 12-month remission (AUC  = 0.76), with an optimal threshold of 11.3 µg/mL (sensitivity 85%, specificity 67%). Treatment was de-escalated in 5% and discontinued in 26% due to primary nonresponse. AEs occurred in 13%, mainly mild dermatologic reactions.

Weekly 80 mg adalimumab appears to be an effective and well-tolerated intensification strategy in pediatric CD patients with pharmacokinetic loss of response. Further prospective studies are needed to confirm these findings and guide optimal use.