Efficacy of filgotinib in moderate to severe ulcerative colitis: a prospective study using partial mayo score, ulcerative colitis endoscopic index of severity, and geboes histopathology score

Filgotinib (FIL), a Janus kinase (JAK) inhibitor, shows clinical efficacy in moderate to severe ulcerative colitis (UC), but no prospective studies have examined endoscopic and histopathological outcomes. This study aimed to evaluate the therapeutic efficacy of FIL in moderate to severe UC using the Partial Mayo Score (PMS), Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and Geboes Histopathology Score (GHS).

Twenty-two patients with clinically moderate to severe refractory UC were enrolled. Remission was defined as PMS 0, UCEIS 0, and GHS <2.0 (sigmoid and rectum). Achievement rates were prospectively evaluated at 12, 24, and 52 weeks after FIL initiation compared to baseline.

Among the 22 patients, comprising Biologic-Naïve (BN, n=12) and Biologic-Experienced (BE, n=10) cohorts, achievement rates were highest for PMS 0, followed by UCEIS 0, and lowest for GHS < 2.0. PMS 0 achievement for BN/BE were 75% (P=0.001)/50% (P=0.031) at 12 weeks, 75% (P=0.003)/70% (P=0.016) at 24 weeks, and 75% (P=0.002)/70% (P=0.016) at 52 weeks. UCEIS 0 achievement for BN/BE were 58.3% (P=0.008)/20% (P=0.016) at 12 weeks, 41.6% (P=0.019)/40% (P=0.016) at 24 weeks, and 50% (P=0.002)/50% (P=0.016) at 52 weeks. GHS <2.0 (sigmoid) achievement for BN/BE were 25%/0% at 12 weeks, 33.3%/10% at 24 weeks, and 25%/10% at 52 weeks. GHS <2.0 (rectum) achievement for BN/BE were 50%/0% at 12 weeks, 41.6%/20% at 24 weeks, and 33.3%/40% at 52 weeks.

FIL appears to be an effective treatment for UC, demonstrating potential for achieving not only clinical remission but also endoscopic and histopathological remission.