Characterization of Biologic Discontinuation Among Pediatric Patients with Crohn's Disease

Background & Aims: Biologic therapies may effectively treat Crohn's disease (CD), and pediatric patients who discontinue multiple biologics risk exhausting treatment options. The frequency and context of biologic discontinuation have not been well-characterized. We aimed to determine patterns of biologic use, discontinuation, and evaluation in pediatric patients with CD. Methods: Pediatric patients with CD at 7 U.S. centers (2010–2020) were identified. Prospective ImproveCareNow registry data were supplemented with medical record abstraction. Biologics included monoclonal antibody and small molecule medications. Therapeutic drug monitoring (TDM) was considered induction if <14 weeks after biologic start, proactive if later during quiescent disease, and reactive during active disease. Results: Of 823 patients included (median age, 13.0 years; 40% female), 86% started biologics (78% infliximab, 21% adalimumab, <1% others). Twenty-six percent used concomitant immunomodulators for ≥12 months. Most (85%) measured TDM including 47% induction, 69% proactive, and 24% reactive. Twenty-nine percent discontinued their first biologic after median 793 days because of inefficacy (34%), anti-drug antibodies (8%), adverse events (8%), or non-adherence (12%). If inefficacy, 86% underwent pre-discontinuation evaluation. If infliximab or adalimumab inefficacy and TDM was done, 62% had levels <10 μg/mL. Proactive TDM and concomitant immunomodulators were associated with 60% and 32% reduced biologic discontinuation. Conclusions: Most children with CD are treated with biologics; 25%–37% discontinue biologics, resulting in 1 in 12 using >2 biologics during pediatric care. Half of patients discontinued biologics without trial of high-dose therapy and 14% without any evaluation. Concomitant immunomodulator use and proactive TDM decreased risk of biologic discontinuation. Strategies are needed to preserve biologic efficacy and prevent biologic discontinuation.