Effectiveness and Safety of Upadacitinib for Acute Severe Ulcerative Colitis

The aim of this retrospective observational study is to investigate and compare the real-world effectiveness and safety of upadacitinib when used as first-line exposure versus rescue exposure in patients with acute severe ulcerative colitis (ASUC). The key questions to be addressed are: In patients with ASUC, does upadacitinib administered as first-line induction exposure result in higher rates of colectomy-free survival, clinical remission, and endoscopic healing compared with its use as rescue exposure following failure of conventional or biologic therapies? What are the differences in the incidence, type, and severity of adverse events between these two real-world treatment exposure patterns? The researchers will conduct a retrospective analysis of medical records and electronic health data from patients diagnosed with ASUC who received upadacitinib either as part of routine first-line clinical care or routine rescue clinical care. All treatment decisions were made by treating clinicians per standard of care; the investigator did not assign or modify any therapeutic interventions. Data will be collected during a defined follow-up period to compare the real-world effectiveness and safety profiles of the two treatment exposure strategies.

This is a retrospective observational cohort study. All interventions described are part of routine clinical care for acute severe ulcerative colitis (ASUC). Treatment decisions were made by treating clinicians per standard of care; the investigator did not prospectively assign, modify, or control any therapeutic interventions. Participants did not receive any intervention specifically for the purpose of this study. The study only involves retrospective analysis of existing medical records to compare real-world outcomes between different treatment exposure patterns.