Comparative Efficacy and Safety of Three Janus Kinase Inhibitors in Ulcerative Colitis: A Real‐World Multicentre Study in Japan

ABSTRACT Background Three Janus kinase (JAK) inhibitors are approved for ulcerative colitis (UC) in Japan. Aim To compare the real‐world efficacy and safety of these three JAK inhibitors in UC. Methods This was a multicentre, retrospective study of patients with UC started on JAK inhibitors. The primary outcome was clinical remission at 10, 26 and 58 weeks, and at the most recent follow‐up. To compare the efficacy and safety among the JAK inhibitors, we created three matched cohorts (upadacitinib vs. filgotinib, tofacitinib vs. filgotinib and upadacitinib vs. tofacitinib) using propensity score matching. Results We identified 228 upadacitinib‐treated patients (median follow‐up 49 weeks; IQR 25–72), 215 filgotinib‐treated patients (follow‐up 56 weeks; IQR 17–82) and 159 tofacitinib‐treated patients (follow‐up 112 weeks; IQR 10–258). Clinical remission rates for upadacitinib, filgotinib and tofacitinib at the most recent follow‐up were 72.8%, 50.6% and 45.8%, respectively. Over 70% of the patients previously treated with other biologics or JAK inhibitors achieved clinical remission with upadacitinib. On multivariate analysis, the number of previous advanced therapies was inversely associated with the efficacy of filgotinib and tofacitinib. Comparative analysis showed that upadacitinib‐treated patients had higher efficacy and lower risk of discontinuation than patients treated with other JAK inhibitors. However, upadacitinib had a significant risk of acne. Conclusions Considering the particularly high efficacy of upadacitinib, even in patients with refractory UC, filgotinib or tofacitinib may be considered as an upfront JAK inhibitor before using upadacitinib. A real‐world, multicentre comparative analysis shows that upadacitinib‐treated patients with ulcerative colitis had higher efficacy and lower risk of discontinuation when compared with patients treated with other JAK inhibitors. However, upadacitinib was associated with a significant risk of acne.