Efficacy and safety of filgotinib for ulcerative colitis: A real-world multicenter retrospective study in Japan.

ABSTRACT

BACKGROUND AND AIMS: While filgotinib, an oral Janus kinase (JAK) 1 preferential inhibitor, is approved for moderately to severely active ulcerative colitis (UC), real-world studies assessing its short- and long-term efficacy and safety are limited. METHODS: This is a multicenter, retrospective study of UC patients who started filgotinib between March 2022 and September 2023. The primary outcome was clinical remission, defined as a partial Mayo score ≤1 with a rectal bleeding score of 0, or Simple Clinical Colitis Activity Index (SCCAI) ≤2 with a blood-in-stool score of 0. Secondary outcomes included clinical response, corticosteroid-free remission, and endoscopic improvement. Outcomes were assessed at 10, 26, and 58 weeks based on patients with available follow-up. Adverse events were evaluated. RESULTS: We identified 238 UC patients and 54% had prior exposure to biologics/JAK inhibitors. The median baseline partial Mayo score and SCCAI were 5 (IQR 3-6) and 4 (IQR 2-7). Clinical remission rates based on per-protocol analysis at 10, 26, and 58 weeks were 47% (70/149), 55.8% (48/86), and 64.6% (31/48), respectively. At a median follow-up of 28 weeks (IQR 10-54) with a discontinuation rate of 39%, the rates of clinical remission, clinical response, corticosteroid-free remission, and endoscopic improvement were 39.9% (81/203), 54.7% (111/203), and 36.5% (74/203), and 43.5% (10/23), respectively. These rates were comparable between biologic/JAK inhibitor-naïve and -experienced patients. While three patients (1.3%) developed herpes zoster infection, no cases of thrombosis or death were reported. CONCLUSIONS: Real-world data demonstrate favourable clinical and safety outcomes of filgotinib for UC.