A Prospective Observational Study on the Efficacy and Safety of Guselkumab in the Treatment of Crohn's Disease Patients Previously Treated With Ustekinumab

This is a prospective, single-center, observational study aimed at evaluating the efficacy and safety of guselkumab in patients with moderate to severe Crohn's disease (CD) who have previously failed or were intolerant to ustekinumab therapy. The study plans to enroll approximately 60 participants aged 18-75 years. Participants will receive guselkumab treatment following a defined induction and maintenance regimen over a total observation period of 52 weeks. The primary endpoint is the proportion of patients achieving clinical remission at Week 52. Secondary endpoints include clinical response, endoscopic improvement, biomarker normalization, quality of life assessment, and safety monitoring.