Carotegrast methyl, an oral α4-integrin inhibitor, was recently approved in Japan for the treatment of active ulcerative colitis (UC). However, real-world data regarding its efficacy and safety remain scarce. This study aimed to assess the clinical effectiveness and safety profile of carotegrast methyl in patients with active UC.

Inclusion Criteria:

• Patients diagnosed with UC based on endoscopic and histological findings
• Patients with clinically and endoscopically moderate UC who were eligible for outpatient treatment (however, patients in clinical remission or with mild clinical activity but endoscopically moderate UC were also considered eligible as an exception)
• Patients who exhibited an inadequate response to or intolerance of 5-ASA formulations (including topical agents) or budesonide formulations (including topical agents)
• Patients who provided informed consent for endoscopic examinations at the start of treatment and during the treatment period
• Patients who agreed to blood sampling and fecal biomarker tests

Exclusion Criteria:

• Patients with severe disease on endoscopy (presumed ineffective due to the drug's characteristics)
• Patients currently using biologics, JAK inhibitors, thiopurines, or calcineurin inhibitors (tacrolimus or cyclosporine)
• Patients with a history of malignancy
• Patients with severe hepatic dysfunction
• Pregnant women or those planning pregnancy
• Patients with acute severe conditions, such as toxic megacolon, sepsis, peritonitis, or infectious colitis

Within 6 months of the publication of study results Data will be available for access for 1 year

The data will be available for use in further scientific research, such as additional analyses, validating clinical outcomes, or investigating new treatment options.