Patterns and predictors of biologic therapy switching in inflammatory bowel disease at a tertiary care center: A retrospective observational study

Abstract

Background: Approximately one‑third of inflammatory bowel disease (IBD) patients fail to respond to anti‑tumor necrosis factor (anti‑TNF) therapy, presenting a significant challenge. The two management strategies are changing to a second anti‑TNF agent or a drug with a different mechanism of action. Methods: A retrospective study was conducted on patients with IBD who initiated biologic therapy, between January 2016 and July 2024. Data were extracted from the records of King Fahad Medical City (KFMC). Categorical data were presented as frequencies and percentages. The χ² test was used to evaluate the association between the choice of first, second, and third biologics with C.D. and U.C. Multivariable hazard ratios (HRs) were calculated to identify predictors of drug change. Kaplan–Meier curves were used to compare time to biological change, stratified by disease type. Results: The study included 607 Crohn’s disease (CD) and 392 ulcerative colitis (UC) patients. Most CD patients were male (56.3%), aged 31–45 (45.5% years), with ileocolonic disease (64.9%), and with a penetrating phenotype (38.6%). UC predominantly affected females (55.6%) aged 31–45 (44.4% years), with extensive colitis (63.3%). Infliximab was the most used biologic, with median persistence times of 69 months (CD) and 47 months (UC). In CD, Infliximab is commonly switched to Adalimumab and Ustekinumab. In UC, Infliximab was primarily switched to Ustekinumab, Adalimumab, and Vedolizumab. Persistence times varied; in CD patients treated with Infliximab, persistence was longer before switching compared with those treated with Adalimumab (P = 0.007). In UC, Infliximab persistence (47 months) exceeded that of Adalimumab (23 months; P = 0.016). Regression analysis identified key predictors of switching. In CD, a family history of IBD significantly increased the risk (HR = 1.46, 95% CI: 1.01–2.10; P = 0.042). In UC, younger age (18–30 years) increased risk (HR = 5.94, 95% CI: 1.09–32.27; P = 0.039), while being single reduced it (HR = 0.50, 95% CI: 0.28–0.89; P = 0.019).