Subcutaneous Infliximab Monotherapy Versus Combination Therapy with Immunosuppressants in Inflammatory Bowel Disease: A Post Hoc Analysis of a Randomised Clinical Trial

Background and Objective: Whether benefits and risks of intravenous (IV) infliximab combotherapy with immunosuppressants versus infliximab monotherapy apply to subcutaneous (SC) infliximab is unknown. This post hoc analysis of a pivotal randomised CT-P13 SC 1.6 trial aimed to compare SC infliximab monotherapy with combotherapy in inflammatory bowel disease (IBD). Methods: Biologic-naïve patients with active Crohn’s disease or ulcerative colitis received CT-P13 IV 5 mg/kg at Week (W) 0 and 2 (dose-loading phase). At W6, patients were randomised (1:1) to receive CT-P13 SC 120 or 240 mg (patients 0.999) or meeting efficacy or biomarker outcomes including clinical remission (62.9% vs 74.1%; p = 0.418). Monotherapy and combotherapy groups had comparable immunogenicity (anti-drug antibodies [ADAs]: 65.5% vs 48.0% [p = 0.271], neutralising antibodies [in ADA-positive patients]: 10.5% vs 16.7% [p = 0.630], respectively). Conclusions: Pharmacokinetics, efficacy and immunogenicity were potentially comparable between SC infliximab monotherapy and combotherapy in biologic-naïve IBD patients. Trial Registration: ClinicalTrials.gov: NCT02883452. Graphical Abstract: [Figure not available: see fulltext.]