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

Background: 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.

Methods: 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.

Results: 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.

Conclusions: 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.