Long-term clinical outcomes with filgotinib in ulcerative colitis: 12-month results from the FILGUITO study

BACKGROUND Filgotinib, a JAK1-preferential inhibitor, has demonstrated efficacy in pivotal clinical trials for moderate-to-severe ulcerative colitis (UC), leading to regulatory approvals. While emerging real-world studies provide short-term effectiveness data, comprehensive long-term evidence—particularly beyond 6 months—remains scarce, especially in heavily biologic-experienced populations. AIM To evaluate the 12-month effectiveness, safety, and predictors of response to filgotinib in a real-world cohort of patients with moderate-to-severe UC treated across multiple centers in Andalusia, Spain. METHODS This multicenter, ambispective observational study (FILGUITO registry) included 104 adults with moderate-to-severe UC initiating filgotinib therapy. Demographic, clinical, laboratory, and endoscopic data were collected at baseline and at 8 weeks, 6 months, and 12 months. Effectiveness outcomes included clinical remission (Mayo partial score < 3 with no subscore > 1 and no rectal bleeding), clinical-biochemical remission (clinical remission plus fecal calprotectin < 250 μg/g), and steroid-free remission (clinical remission with no corticosteroid courses from week 8). Safety was assessed through adverse event monitoring. RESULTS The median age was 40.7 years (IQR: 29.5-51.0), with 56.7% male patients. The majority (79.8%) had prior advanced therapy exposure, with a median of 1 prior biologic (IQR: 1-3). Clinical remission rates were 60.8% at 8 weeks, 61.4% at 6 months, and 60.3% at 12 months (all P < 0.001 vs baseline). Clinical-biochemical remission reached 33.0%, 38.6%, and 31.0% at the same timepoints. Steroid-free remission was achieved in 60.0% at 6 months and 56.9% at 12 months. Median fecal calprotectin decreased significantly from 2000 μg/g at baseline (IQR: 755.8-2392.5) to 153 μg/g at 12 months (IQR: 21.3-569.0, P < 0.001). Treatment discontinuation occurred in 22.1% of patients by 12 months, primarily due to lack of response. Serious adverse events were rare (2.8%), with a favorable safety profile. Patients with only one prior biologic showed higher remission rates compared to those with multiple prior treatments. CONCLUSION Filgotinib demonstrates sustained clinical effectiveness and a favorable safety profile over 12 months in a real-world UC cohort with extensive prior biologic exposure. Effectiveness is optimized at earlier treatment lines, though meaningful benefit persists in heavily pre-treated populations.