Real-World Data on the Effectiveness and Safety of Filgotinib for Ulcerative Colitis in Japanese Patients: A Single-Center Experience.

ABSTRACT

Introduction Filgotinib is a JAK-1 selective inhibitor approved for ulcerative colitis (UC) treatment in Japan. Its effectiveness has been confirmed but remains unknown in actual clinical practice. Therefore, we aimed to evaluate the effectiveness and safety of filgotinib and identify suitable patients in the Japanese population. Methods We retrospectively reviewed the background, clinical course, and laboratory data of patients treated with filgotinib 200 mg for UC between May 2022 and December 2023. Results The median observation period for the 25 patients was 232 days (interquartile ranges (IQR) 102-405). The median age of the patients was 43 years (IQR 29-55), disease duration was nine years (IQR 2-12), and 36% (9/25) of patients were biologic or small molecule naïve. The median patient-reported outcome (PRO2) and partial Mayo (pMayo) scores at agent initiation were 3 (IQR 1-4) and 4.5 (IQR 3-6), respectively. The PRO2 and pMayo scores improved significantly two weeks after treatment initiation (p < 0.05). Clinical remission rates at 24 weeks after treatment initiation were 60% (15/25) for PRO2 ≤ 1 and 52% (13/25) for pMayo ≤ 1. The Mayo endoscopic subscore significantly improved after filgotinib initiation (p=0.04), and the endoscopic remission rate was 47% (8/17). At 24 weeks, patients in clinical remission, compared to those not in remission, had significantly lower baseline PRO2 and pMayo scores and longer disease duration (p=0.03, p=0.03, and p=0.04, respectively). The filgotinib persistence rate was 68% (17/25), with no discontinuation because of adverse events. Patients who continued treatment had significantly lower PRO2, pMayo scores, and blood neutrophil counts at initiation than those who discontinued (p=0.02, p=0.03, and p=0.02, respectively). Conclusion Filgotinib appears to be effective and safe in Japanese patients with UC. Effectiveness and persistence were high in patients whose PRO2 and pMayo scores were low at the time of treatment initiation.