Biomarkers predicting the effect of anti‐TNF treatment in paediatric and adult inflammatory bowel disease

Abstract Objectives Paediatric and adult inflammatory bowel disease (pIBD, aIBD) patients may lose response to anti‐tumour necrosis factor (TNF) treatment within the first year. Adult‐extrapolated weight‐based dosing is incorrect in children, due to age‐related pharmacokinetic differences. We investigated biomarkers for initial and maintenance of response to infliximab (IFX) or adalimumab (ADA), comparing pIBD and aIBD patients. Methods In this prospective, observational study, pIBD ( n = 24) and aIBD ( n = 21) patients were included when initiating anti‐TNF. Escalation from standard dosing and continued anti‐TNF at 12 and 18 months were assessed. Biomarkers included clinical laboratory parameters, faecal calprotectin (FCP) and IFX trough levels (TLs). Plasma proteomics was performed in pIBD. Results During our study, treatment escalation (in clinical loss of response) occurred more common in pIBD versus aIBD ( p = 0.02). We established that IFX therapy escalation in pIBD patients was not due to low infliximab levels. We identified 9 pro‐inflammatory proteins that were elevated in patients losing response. Conclusion Anti‐TNF exposure‐response relationship may be different in pIBD versus aIBD. No biomarkers for maintained response were identified, but 9 inflammatory proteins were of interest as potential predictors for loss of response in pIBD.