Advanced Therapies Show Reduced Efficacy in Ileal vs Colonic Crohn’s Disease

Advanced therapies for Crohn’s disease (CD) demonstrate lower efficacy in ileal disease compared with colonic disease, according to a systematic review and meta-analysis of randomized controlled trials. The findings highlight disease location as an important factor in treatment selection and expected response.

Investigators analyzed 14 randomized controlled trials including 3,139 patients with moderate-to-severe CD, comparing advanced therapies with placebo. Treatments were grouped by mechanism of action, including anti–interleukin agents, Janus kinase (JAK) inhibitors, anti-integrins, and tumor necrosis factor (TNF) antagonists. Outcomes were stratified by disease location, focusing on isolated colonic versus ileal disease.

Across all therapies, treatment efficacy was significantly higher in colonic disease (odds ratio [OR], 4.09) compared with ileal disease (OR, 1.80). Differences were observed across drug classes. Anti–interleukin therapies showed greater efficacy in colonic disease (OR, 4.29) than in ileal disease (OR, 2.31), although the difference did not reach statistical significance. Anti-integrins demonstrated similar efficacy across locations.

JAK inhibitors showed the most pronounced disparity. These agents were effective in colonic disease (OR, 4.37) but not in ileal disease (OR, 1.01), indicating limited benefit in patients with isolated ileal involvement. Heterogeneity across studies was low to moderate.

The authors concluded that “the magnitude of efficacy of advanced therapies for ileal CD is generally lower compared with isolated colonic CD,” and noted that “JAK inhibitors [show] particularly limited efficacy for ileal disease.”

Reference
Lee HH, Yuan Y, Boland BS, Chang JT, Jairath V, Singh S. Efficacy of advanced therapies in achieving remission by disease location in Crohn's disease: a systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2026;24(4):923-931. doi:10.1016/j.cgh.2025.07.009