Efficacy and safety of Risankizumab for moderate-to-severe Crohn's disease: first Asian real-world data (STAR trial).

Background: Crohn's disease (CD) remains a challenging condition, especially in patients with moderate-to-severe disease. Risankizumab (RZB), an anti-IL-23p19 monoclonal antibody, has shown efficacy in clinical trials. However, real-world data (RWD) in Asian populations are limited.

Objectives: To assess the effectiveness and safety of Risankizumab in Asian patients with CD.

Design: Multicenter cohort study.

Methods: This study enrolled adult patients with moderate-to-severe CD who received Risankizumab between September 2024 and May 2025 in Taiwan. Efficacy was assessed at weeks 4, 8, and 12 using CD Activity Index (CDAI), patient-reported outcomes-2 (PRO2), and inflammatory bowel disease (IBD)-disk scores. Safety outcomes and treatment response by prior biologic exposure, including Ustekinumab (UST), were evaluated.

Results: Forty-nine patients (mean age 41.5 years, 69.4% male) were included. Clinical response rates were 53.1%, 75.5%, and 91.8% at weeks 4, 8, and 12, respectively; clinical remission was achieved in 12.2%, 22.4%, and 42.9%. PRO2 remission reached 53.5% by week 12. Both CDAI and IBD-Disk scores improved at weeks 4, 8, and 12 with statistical significance (p < 0.0001). Transmural healing was observed in 16.3% of patients at week 12. Clinical remission at week 12 was consistent regardless of prior Ustekinumab exposure (exposed 36.36% vs naïve 44.74%, p = 0.630) or biologic-naïve status (exposed 36.84% vs naïve 63.63%, p = 0.119). No severe adverse events were reported, but mild events included headache and transient liver enzyme elevation (each 2.04%).

Conclusion: Risankizumab may demonstrate significant short-term efficacy and favorable safety in real-world treatment of moderate-to-severe CD in an Asian cohort. Long-term data are needed to confirm sustained outcomes and guide their optimal use across diverse CD populations.