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 na & iuml;ve 44.74%, p = 0.630) or biologic-na & iuml;ve status (exposed 36.84% vs na & iuml;ve 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. Plain language summary Can a new immune therapy improve Crohn/s disease in Asian patients? A real-world study in Taiwan shows promising results Why was this study done? Crohn's disease (CD) is a long-term illness that causes inflammation in the digestive tract, leading to symptoms like abdominal pain, diarrhea, and fatigue. Managing moderate-to-severe cases can be difficult, especially when patients do not respond well to standard treatments. Risankizumab is a newer biologic medication that blocks a protein called IL-23, which plays a key role in causing inflammation. It has shown good results in clinical trials, but real-world evidence in Asian patients was still lacking. What did the researchers do? Doctors from seven major hospitals in Taiwan worked together to track 49 adults with moderate-to severe CD who were treated with Risankizumab between 2024 and 2025. They looked at how well the drug reduced symptoms and improved quality of life over 12 weeks. They also monitored side effects and compared results in patients who had previously used other biologic treatments versus those who had not. What did the researchers find? After 12 weeks, about 92% of patients showed improvement in symptoms, and 43% reached clinical remission. Even among patients who had already tried other biologic drugs, Risankizumab still worked well. Many patients no longer needed steroids, and both doctor-measured scores and patient-reported outcomes showed significant improvement. Only a few people experienced mild side effects like headaches or minor liver enzyme changes no serious complications were found. What do the findings mean? This is the first real-world study in Asia to show that Risankizumab is an effective and safe option for treating CD. These results support its use even in patients who didn't respond to earlier treatments. The study helps doctors make more informed decisions and supports broader use of this therapy in Asian populations.