Comparative Efficacy of Janus Kinase Inhibitors (JAKis) for Ulcerative Colitis in Japanese Regional Healthcare Facilities: A Real-World Database Study

Background and aim: Tofacitinib (TOF), filgotinib (FIL), and upadacitinib (UPA) are approved Janus kinase inhibitors (JAKis) for ulcerative colitis (UC), but real-world comparative data remain limited. This study assessed their efficacy, persistence, and safety in regional Japanese hospitals. Methods: We retrospectively analyzed 148 UC treatment sessions (TOF, 60; FIL, 53; UPA, 35). The primary outcome was clinical remission (partial Mayo score ≤1 with rectal bleeding score 0). Secondary outcomes included clinical response, steroid-free remission, and treatment persistence. Adverse events and biologics (Bio)/JAKi subgroup data were collected. Results: At week 8, clinical remission rates were similar for TOF (46%), FIL (44%), and UPA (46%). At week 24, FIL had the highest remission rate (61%) vs. TOF (46%) and UPA (41%), a trend that continued at week 48 (59%, 41%, 44%). FIL also showed the highest remission in both Bio/JAKi-naïve and failure sessions at weeks 24 and 48. UPA had the highest clinical response at week 8 (67%). TOF showed stable remission over time (46%, 46%, 41%). Steroid-free remission was more frequent with FIL at weeks 24 (61%) and 48 (59%) than with TOF (46%, 41%) or UPA (35%, 33%). Persistence was similar across agents through week 24. Safety profiles aligned with prior data, though rare events such as Pneumocystis jirovecii pneumonia and interstitial pneumonia were noted. Conclusions: FIL showed favorable remission rates, especially in Bio/JAKi-naïve patients, and remained effective after prior failures, suggesting broad applicability. UPA and TOF showed similar remission rates in our cohort.