P0738Real-world experience of switching from intravenous to subcutaneous infliximab in pediatric Inflammatory Bowel Disease patients: a multicenter retrospective cohort from the Canary Islands, Spain.

Abstract Background Subcutaneous infliximab (IFX-SC) provides logistical advantages and more stable pharmacokinetics than intravenous infliximab (IFX-IV). Real-world evidence in pediatric inflammatory bowel disease (PIBD) remains limited. We assessed clinical effectiveness, pharmacokinetics, and safety after switching from IFX-IV to IFX-SC across three pediatric IBD units in the Canary Islands, Spain. Methods Retrospective multicenter study including patients 18 years who underwent elective switch from IFX-IV to IFX-SC between 2023–2025. Clinical indices (PCDAI/PUCAI), fecal calprotectin (FC), C-reactive protein (CRP) and trough infliximab levels (TDM) were collected at baseline (last IFX-IV), 3, 6 and 12 months. Paired changes were evaluated using Wilcoxon tests. Primary endpoint: clinical remission at 6 months. Secondary endpoints: biomarker evolution, TDM stability, adverse events, hospitalizations and treatment persistence. Results Eleven patients were included (73% Crohn’s disease; 18% ulcerative colitis; 9% unclassified; mean age 15.4 years; 82% male). Six (54.5%) switched from optimized IFX-IV and five (45.5%) initiated IFX-SC for convenience or logistical reasons. 9/11 have completed 12 month of follow up. All were in clinical remission at baseline, which was maintained in 100% at the end of the follow up 6 or 12 months . PCDAI improved from baseline to 3 months (median 9 → 3; p = 0.042) and remained stable thereafter; PUCAI was 0 at all timepoints. CRP remained low without significant changes. FC decreased from 444 µg/g at baseline to 191 µg/g at 3 months and 180 µg/g at 6 months, although not statistically significant. TDM values were high and stable (baseline 15.5 µg/mL; 3 months 18.8 µg/mL; 6 months 18.7 µg/mL; all p 0.2). No adverse events, hospitalizations, steroid use or discontinuations were recorded. Treatment persistence was 100% at the end of the follow up (9/11 12 month). Conclusion Switching from IFX-IV to IFX-SC in this multicenter pediatric cohort was highly effective and safe, with stable therapeutic exposure and full maintenance of clinical remission. IFX-SC appears to be a practical and well-tolerated alternative to intravenous therapy in PIBD, particularly in settings where logistical burden and treatment autonomy are relevant. Larger cohorts with longer follow-up are needed Conflict of interest: Alberto, José Ramón: No conflict of interest De La Barreda Heusser, Laura: No conflict of interest Marquez Rodriguez, Juan Alberto: I have provided scientific advice/participated in medical meetings for Kern and Takeda. I am receiving a gratification for this presentation. Rodríguez Díaz, Ana Eva: No conflict of interest Carrillo Palau, Marta: No conflict of interest Fuentes Ferrer, Manuel Enrique: No conflict of interest Dr. Hernandez Camba, Alejandro: I have served as a speaker or has received research or education funding or advisory fees from Lilly, Takeda, J and J, FAES Pharma, Falk, Abbvie, Adacyte Therapeutics, Tyllots, Ferring, Kern Pharma, Alfasigma and Chiesi.