Infliximab Serum Level Assessment After Switching from Intravenous to Subcutaneous Administration: The ISLASIS Study

Introduction

Subcutaneous infliximab (SC-IFX) has emerged as an alternative maintenance therapy for inflammatory bowel disease (IBD), offering absorption and sustained systemic exposure. Although higher and more stable serum concentrations have been reported with SC-IFX, prospective real-world data evaluating pharmacokinetic evolution after transition from intravenous infliximab (IV-IFX) remain limited, particularly in Latin America. We assessed infliximab trough concentrations following transition from IV-IFX to SC-IFX and explored associations with biomarkers and clinical outcomes.