Overcoming anti-Infliximab antibodies and maintaining Infliximab achieves superior durability and outcome compared to switching to Adalimumab.

BACKGROUND AND AIMS: The development of antibodies to infliximab (ATI) is a major challenge in pediatric inflammatory bowel disease (IBD). This real-world study aimed to identify predictors of ATI, evaluate strategies to overcome ATI, and compare the durability of continuing infliximab (IFX) versus switching to adalimumab (ADA) after ATI development.

METHODS

We retrospectively analyzed 194 pediatric IBD patients treated with IFX from 2010 to 2024. ATI titers were measured uniformly before each infusion. Demographic data, disease characteristics, ATI titers, infusion reactions, management strategies, and treatment durability were collected and analyzed.

RESULTS

ATI developed in 52 of 194 patients (26.8 %), more frequently in Crohn's disease (31.2 %) than ulcerative colitis (16.1 %, p < 0.01), and was associated with female gender (57.7 % vs. 39.4 %, p = 0.03) and younger age at diagnosis. High-titer ATI (≥8 mcg/ml-eq) correlated with infusion reactions (56.5 % vs. 3.5 %, p < 0.001). ATI was managed with dose/interval adjustment (61.9 %), immunomodulator addition (16.7 %), or both (21.4 %). IFX continuation was successful in 71.4 %, especially in low-titer ATI (92.0 % vs. 41.2 %, p < 0.001). IFX durability after ATI was significantly longer (median 94 months) than ADA after switching (47 months, p < 0.01).

CONCLUSIONS

About 27 % of pediatric IBD patients developed ATI to IFX. Personalized management can restore IFX efficacy and provides superior long-term outcomes compared to switching to ADA.