4CPS-038 Real-life study of the use of tumour necrosis factor inhibitors in paediatric patients with inflammatory bowel disease

<h3>Background and Importance</h3> Paediatric inflammatory bowel disease (PIBD) is a chronic immune-mediated pathology with increasingly early diagnosis. The only approved biologics drugs for PIBD are infliximab (IFX) and adalimumab (ADA), both tumour necrosis factor inhibitors (anti-TNF). <h3>Aim and Objectives</h3> The aim of this study is to describe the use of IFX and ADA as first-line therapies for PIBD and to assess their effectiveness and safety. <h3>Material and Methods</h3> Retrospective observational study at a paediatric hospital, including patients who began anti-TNF treatment from January 2021 to March 2024. <h3>Collected variables</h3> demographics (age, sex, weight, diagnosis), pharmacological (prescribed drugs, dose and frequency of administration), analytical (drug and faecal calprotectin (FC) levels), and adverse reactions. <h3>Cut-off points</h3> Drug intensification: higher doses/frequencies than IFX and ADA data sheet. Analytical response: last 5 FC averages ≤ 120 µg/g. Optimal maintenance plasma levels seeking mucosal healing: IFX ≥ 7–10 µg/mL, ADA ≥ 5–8 µg/mL. Data sources: Electronic Health Record (HCIS), Modulab, Farmatools. Statistical analysis: median and frequency distribution (%). <h3>Results</h3> 54 patients were included, 35 boys (64,8%), with a median age of 14 years (2–18 years). Ulcerative colitis (UC) was present in 13 (24.1%) patients, and Crohn’s disease (CD) in 41 (75.9%). 31 (57.4%) started with infliximab (IFX); 20 had CD and 11 had UC. 16 (51.6%) continued it, 9 (29%) switched to second-line, and 6 (19.4%) to third-line treatment. 23 (42.6%) started with adalimumab (ADA); 21 CD and 2 UC. 11 (47.8%) continued, 6 (26.1%) moved to second-line, 5 (21.7%) to third, and 1 (4.4%) to a fourth drug. 24 (44.4%) began on standard doses; 18 with ADA, 6 with IFX. 30 (55.6%) required intensified frequency of administration; 8 with ADA, 22 with IFX. 29 (53.7%) patients presented decrease in CF ≤ 120 µg/g. 36 (66.7%) reached optimal drug levels, with 17 (31.5%) achieving this on standard dosing. Target changes were due to anti-TNF antibodies or clinical worsening in 25 of 27 patients; two reported adverse reactions (psoriasis). <h3>Conclusion and Relevance</h3> Our study shows that IFX and ADA are highly effective and safe for PIBD, although many patients need higher doses or intensified regimens. Close monitoring of drug levels and analytical parameters are crucial for personalised treatment and effective management of paediatric patients. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest