Real-world data on the effectiveness of risankizumab as induction therapy for ustekinumab-refractory ulcerative colitis.

Abstract

Ulcerative colitis (UC) is a chronic inflammatory bowel disease resulting from inappropriate immune responses and is characterized by diarrhea and bloody stools. Currently, numerous biologics and small-molecule agents have been developed and have improved outcomes in patients with UC. 1 Interleukin-23 (IL-23), a heterodimeric cytokine composed of p19 and p40 subunits, plays an important role in inflammatory bowel disease pathogenesis. 2 Risankizumab (RZB) is a monoclonal antibody targeting the IL-23 p19 subunit, and its efficacy in treating UC has been demonstrated in a phase 3 clinical trial. 3 However, unlike the phase 3 trial for Crohn’s disease, 4,5 the trial for UC did not examine patients with prior exposure to ustekinumab (UST). Consequently, the efficacy of RZB in such patients remains unclear. Therefore, this study aimed to evaluate the short-term real-world efficacy of RZB in patients with UC previously treated with UST at our institution. This retrospective cohort study included patients with UC who were previously exposed to UST and were initiated on RZB therapy between July 2024 and August 2025