Characteristics of Ulcerative Colitis Patients Maintaining Remission with 12-Week Ustekinumab Administration

Background: Ustekinumab (UST) is administered at 8- or 12-week intervals to maintain remission in ulcerative colitis (UC). This study aimed to identify characteristics of UC patients who can sustain remission with 12-week UST intervals.
Methods: We analyzed UC patients at our institution whose UST maintenance therapy was extended to 12 weeks between May 2020 and December 2024. Patients achieving both a partial Mayo score (pMS) < 3 and fecal calprotectin (FCP) < 100 mg/kg at 48 weeks post-extension were classified as the success group; others were the non-success group. We compared patient characteristics, disease severity at UST initiation and interval extension, treatment history, and FCP changes between groups.
Results: Among 20 UC patients whose UST interval was extended to 12 weeks, 8 were initially extended to 10 weeks before reaching 12 weeks. Overall, 12 of 20 maintained remission at 12-week intervals. There were no significant differences in CRP, FCP, or advanced therapy (AT) naive status at treatment initiation or extension. FCP tended to decrease more in the success group (week 16: 274 vs. 1555, p = 0.057; week 24: 224 vs. 744.5, p = 0.098).
Conclusion: The ability to maintain remission with 12-week UST intervals appears to be predicted by post-treatment FCP changes rather than disease activity at treatment initiation or interval extension.