Real-World Ustekinumab Experience in Ileum-Dominant Versus Colonic Crohn's Disease

Crohn's disease (CD) presents with diverse phenotypes. It remains unclear if CD location affects therapy efficacy. The aim of this study was to compare the real-world performance of ustekinumab in ileum-dominant and colonic CD.

We performed a single-center, IRB-approved, retrospective review of all adult CD patients who received ustekinumab. We stratified patients by ileal involvement: ileum-dominant (ileal and ileocolonic) and colonic CD. The primary outcome was the absence of ulcers on follow-up colonoscopy. The secondary outcomes included CRP, calprotectin, surgery, and hospitalization. Chi-square tests (or Fisher's exact test) and 2-sample t-tests (or Wilcoxon's rank-sum test) were used to compare categorical and numeric variables between groups, respectively; analyses were performed using R Computing Software versions 3.6.1.

Eighty-four patients with ileum-dominant CD and 27 patients with colonic CD were treated with ustekinumab. The median time to follow-up endoscopy was 13 months. Follow-up colonoscopy after ustekinumab therapy was ulcer-free in 45% of ileum-dominant CD and 76% of colonic CD (P = .02). Of patients with ulcers prior to starting ustekinumab, 24% of ileum-dominant CD and 67% of colonic CD were ulcer-free (P = .01). There were similar rates of hospitalizations and surgery and no significant differences in mean calprotectin and CRP between the two groups on follow-up after ustekinumab therapy.

This real-world experience of ustekinumab demonstrates higher rates of endoscopic healing among colonic CD when compared to ileum-dominant CD. Disease location may predict endoscopic healing by ustekinumab. Further studies are necessary to expand our understanding of ustekinumab responsiveness to different CD phenotypes.