P1123The Practical Utility of Janus Kinase Inhibitors in Ulcerative Colitis: A Real-World Multicentre Study

Abstract Background Three types of Janus kinase (JAK) inhibitors are currently available for the treatment of ulcerative colitis (UC) in Japan. Although several studies have reported their efficacy and safety in clinical practice, real-world data remain limited. Therefore, we investigated treatment outcomes across multiple local medical institutions. Methods This was a multicentre, retrospective study including patients with UC who were prescribed a JAK inhibitor between July 2007 and December 2025. The primary outcomes were clinical remission and response at 4 weeks, 52 weeks, and at the most recent follow-up. The efficacy and safety profiles of each JAK inhibitor were compared descriptively. Results A total of 74 patients with UC were treated with JAK inhibitors during the study period: 23 with tofacitinib, 29 with filgotinib, and 22 with upadacitinib. Clinical remission rates at 4 and 52 weeks were 70.0% and 47.6% for tofacitinib, 86.2% and 60.7% for filgotinib, and 95.2% and 72.2% for upadacitinib, respectively. Among patients who underwent JAK inhibitor intraclass switching, tofacitinib was used in 4.4% (1/23), filgotinib in 6.9% (2/29), and upadacitinib in 68.2% (15/22). Upadacitinib demonstrated higher efficacy than the other JAK inhibitors, including in patients who had previously received a different JAK inhibitor. One case of herpes zoster infection occurred in a patient treated with tofacitinib; however, there was no significant difference in the incidence of adverse events among the three JAK inhibitors. No cases of death, malignancy, or major acute cardiovascular events were observed. In this study, JAK inhibitors were more frequently prescribed for patients intolerant to 5-aminosalicylic acid (5-ASA) (35.1%). Conclusion Upadacitinib demonstrated favourable therapeutic efficacy even in community-based medical settings. The accumulation of further detailed real-world data will help optimise the selection of the most appropriate JAK inhibitor for individual patients with ulcerative colitis. Conflict of interest: Dr. Mori, Statoshi: No conflict of interest Maeda, Nobuhisa: No conflict of interest Kuwazuru, Kosuke: No conflict of interest Sameshima, Yoichi: No conflict of interest Tanaka, Akihito: No conflict of interest Komaki, Yuga: No conflict of interest Kanmura, Shuji: No conflict of interest