Effectiveness of switching to subcutaneous infliximab in inflammatory bowel disease patients with inadequate biochemical response during intravenous administration.

Infliximab (IFX) has transformed the management of inflammatory bowel diseases (IBD). While intravenous (IV) IFX has been effective, a subcutaneous (SC) formulation offers advantages in convenience and cost. However, there is lack of evidence regarding the transition from IV to SC-IFX, especially for patients with inadequate responses. This study investigates the effectiveness of switching from IV to SC-IFX in patients with inadequate responses during IV maintenance therapy. A retrospective study enrolled IBD patients who transitioned to SC-IFX after demonstrating inadequate responses during IV maintenance therapy. The study collected data of demographics of patients and dose and therapies administered prior to the IV-IFX. Primary outcomes included improvements in C-reactive protein (CRP) or fecal calprotectin (FC) levels. This study evaluated the trough levels and its differences between pre- and post-switching. Among 44 patients included, 10 exhibited CRP elevation before the switch, with 6 showing normalization post-switch. Similarly, 42 patients had elevated FC levels pre-switch, with 26 experiencing reductions post-switch. Trough levels increased after the switch. However, there were no significant differences between responders and non-responders. This study is the first study to investigate the transition therapy of IV to SC-IFX in patients with inadequate response. This suggests that SC-IFX could be a viable alternative in the management of IBD. However, further research is necessary to evaluate its efficacy in a larger population of patients who exhibit inadequate responses during IV-IFX maintenance therapy.