REAL-WORLD DURABILITY OF BIOLOGICS IN PEDIATRIC IBD: INSIGHTS FROM THE KOREAN HIRA DATABASE

Abstract BACKGROUND Although biologics are widely used in pediatric inflammatory bowel disease (IBD), the long-term durability of the biologics in children remains incompletely understood. METHODS Using the Korean Health Insurance Review and Assessment Service database (2007-2023), we identified patients aged 6-17 years with Crohn’s disease (CD) or ulcerative colitis (UC) who initiated infliximab (IFX) or adalimumab (ADA) as first biologic therapy. Persistence was evaluated using Kaplan-Meier analysis at 6 months, 1 year, and 5 years. Subgroup analyses assessed concomitant immunomodulator (IM) use and duration. RESULTS Among 2542 CD patients, 1895 initiated IFX and 647 ADA; 581 UC started IFX. Among CD, IFX persistence was 97.47%. 88.0%, and 78.64%, while ADA showed 95.58%, 87.17%, and 72.79%. In UC, IFX persistence was 76.21%, 40.35% and 24.66%. In CD, IFX with IM improved durability compared with monotherapy (HR 0.67, 95% CI 0.52-0.85, p = 0.0003 at 1 year; HR 0.77, 95% CI 0.63-0.95, p = 0.0078 at 5 years), mainly when IM was continued ≥6 months, while ADA showed no clear durability benefit from the combination therapy. In UC, IFX durability improved with IM ≥ 6months at 1 year (HR 0.65, 95% CI 0.44-0.96, p = 0.023), while the effect was attenuated over time. CONCLUSION In this nationwide, real-world study, IFX and ADA demonstrated comparable persistence in CD, while IFX durability in UC declined substantially. Sustained IM use for ≥6 months enhanced IFX durability, whereas short-term use offered limited benefit. These findings underscore the importance of IM duration in optimizing anti-TNF therapy in pediatric IBD and provide robust evidence from a nationwide population-based cohort.