Abstract Background Upadacitinib, a selective Janus kinase 1 inhibitor, has demonstrated efficacy in clinical trials for inflammatory bowel disease (IBD); however, real-world data from Asian populations remain limited. Methods We conducted a retrospective study to evaluate the real-world effectiveness and safety of upadacitinib in Korean patients with ulcerative colitis (UC) or Crohn’s disease (CD). Adult patients who initiated upadacitinib between July 2021 and November 2024 were included. Symptom-based clinical activity was assessed using patient-reported outcomes (PRO2) at baseline and six months. Adverse events (AEs) and surgical interventions were also documented. Results Forty patients (28 CD, 12 UC) were analyzed. At six months, symptom-based clinical remission was achieved in 82.4% of CD and 81.8% of UC patients, with clinical response rates of 88.2% and 90.9%, respectively. No clinical or treatment-related factors were significantly associated with remission in univariate analyses. AEs occurred in 57.5% of patients, all grade 1, and no treatment discontinuations were required. Conclusion Upadacitinib was effective and well tolerated over six months in Korean patients with moderate-to-severe IBD, including those with prior biologic experienced. These findings support its use in routine clinical practice, while highlighting the need for prospective studies to confirm its long-term safety and efficacy in Asian populations. References: 1.Chovatiya R, Paller AS. JAK inhibitors in the treatment of atopic dermatitis. J Allergy Clin Immunol 2021;148:927–940. 2.Fayand A, Hentgen V, Posseme C, et al. Successful treatment of JAK1-associated inflammatory disease. J Allergy Clin Immunol 2023;152:972–983. 3. Ahn SH, Lee YJ, Lim DS, et al. 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Cardiovascular and Cancer Risk with Tofacitinib in Rheumatoid Arthritis. N Engl J Med 2022;386:316–326. 23.colitis in patients with and without prior exposure to anti-tumor necrosis factor α antibody. Intest Res 2025. 24.López-Sanromán A, Esplugues JV, Domènech E. Pharmacology and safety of tofacitinib in ulcerative colitis. Gastroenterol Hepatol 2021;44:39–48. 25. Harrington R, Harkins P, Conway R. Janus Kinase Inhibitors in Rheumatoid Arthritis: An Update on the Efficacy and Safety of Tofacitinib, Baricitinib and Upadacitinib. J Clin Med 2023;12:6690. Conflict of interest: Prof. Kim, Ji Eun: Nothing to declare Lee, Yeong Chan: Nothing to declare Kim, Minjee: Nothing to declare Kim, Eun Ran: Nothing to declare Chang, Dong Kyung: Nothing to declare Kim, Young-Ho: Nothing to declare Hong, Sung Noh: No conflict of interest
Kim et al. (Thu,) studied this question.