A propensity score weighted comparison of intravenous and subcutaneous infliximab as maintenance treatment in patients with inflammatory bowel disease: The CISI study
Fabio Salvatore Macaluso, Silvia Calderone, Sara Renna, Angelo Casà, Rosalba Orlando, Emanuele Orlando, Raffaele Li Voti, Josephine Vastarella, Samuele Armetta, Simona Morello, Ambrogio OrlandoBackground
Comparing intravenous (IV) infliximab (IFX) with subcutaneous (SC) CT-P13 in inflammatory bowel disease (IBD) may inform clinical practice, particularly in patients in stable remission receiving maintenance therapy.
Objectives
To compare IV IFX and SC CT-P13 as maintenance therapy in patients with IBD.
Design
Retrospective, single-centre, observational cohort study using propensity score weighting.
Methods
Adult patients with Crohn’s disease (CD) or ulcerative colitis (UC) in stable steroid-free remission while receiving maintenance IV IFX, 5 mg/kg every 8 weeks, were included. Patients switched to SC CT-P13 were compared with patients who continued IV IFX. A propensity score-weighted analysis using inverse probability of treatment weighting was applied. The primary endpoint was time to treatment failure, defined as a composite endpoint including re-switch from SC to IV IFX, IV IFX dose intensification, steroid-requiring flare, switch to another advanced therapy, or IBD-related surgery.
Results
Among 251 patients, 135 had CD (53.8%) and 116 had UC (46.2%); 134 remained on IV IFX and 117 switched to SC CT-P13. Mean follow-up was 24.7 ± 29.8 months in the IV group and 20.9 ± 14.9 months in the SC group. Time to treatment failure was not significantly different between groups (log-rank p = 0.10; HR 0.71, 95% CI 0.45–1.12). A significant time-dependent effect was observed (p = 0.005): discontinuation risk was initially higher after switching, but progressively decreased over time, becoming lower after approximately 8 months.
Conclusion
In patients with IBD in stable steroid-free remission, switching to SC CT-P13 may provide treatment persistence, safety, and disease control comparable to continued IV IFX.