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.
Age 18-75 years.
Diagnosis of Crohn's disease for at least 3 months.
Moderate to severe disease activity (CDAI 220-450).
Primary non-response, or Secondary loss of response, or Intolerance leading to discontinuation.
Previous exposure to any anti-IL-23p19 therapy (including guselkumab).
Active intestinal infection, unremoved stenotic lesions with obstructive symptoms, short bowel syndrome, stoma, or recent abdominal abscess (<8 weeks).
History of malignancy (except certain skin cancers), active tuberculosis, or severe opportunistic infection.
Pregnancy, lactation, or planned pregnancy during the study period.