Subcutaneous infliximab for inflammatory bowel disease: Clinical evidence, pharmacokinetics, and implementation challenges

Infliximab (IFX) has traditionally been administered intravenously (IV) for the treatment of moderate-to-severe ulcerative colitis (UC) and Crohn’s disease (CD). Advances in biologic drug delivery and evolving patient preferences have led to the development of subcutaneous (SC) formulations that permit self-administration. Compared with IV dosing, SC IFX offers several potential advantages, including greater convenience and flexibility, reduced healthcare utilization, and more stable serum drug exposure. Evidence supporting SC IFX has emerged from pharmacokinetic studies, randomized controlled trials, real-world cohorts, and meta-analyses. These studies suggest that SC IFX is effective and generally well tolerated in selected patients with inflammatory bowel disease (IBD), particularly following successful IV induction therapy. Despite these data, uptake of SC IFX in routine clinical practice remains relatively limited. Potential barriers include prescriber familiarity with IV therapy, concerns regarding patient adherence, reimbursement structures, and limited awareness of SC formulations. In this review, we summarize the current evidence supporting SC IFX, critically examine pharmacokinetic and immunogenicity considerations, discuss practical implementation challenges, and highlight unresolved questions regarding patient selection, dose optimization, and long-term positioning of SC IFX within contemporary IBD management.