Feagan BG, Danese S, Loftus EV, et al. - Researchers conducted this phase 2b/3, double-blind, randomized, placebo-controlled trial including two induction studies and one maintenance study in 341 study centers in 40 countries with the aim to determine the efficacy and safety of filgotinib, a once-daily, oral Janus kinase 1 preferential inhibitor, in the treatment of ulcerative colitis. Enrollment was performed of patients who were aged 18–75 years with moderately to severely active ulcerative colitis for at least 6 months before enrolment (induction study A: inadequate clinical response, loss of response to or intolerance to corticosteroids or immunosuppressants, naive to tumor necrosis factor [TNF] antagonists and vedolizumab [biologic-naive]; induction study B: inadequate clinical response, loss of response to or intolerance to any TNF antagonist or vedolizumab, no TNF antagonist or vedolizumab use within 8 weeks before screening [biologic-experienced]). A total of 2,040 patients were screened for eligibility between Nov 14, 2016, and March 31, 2020. In induction study A, they enrolled 659 patients and randomly assigned them to receive filgotinib 100 mg (n = 277), filgotinib 200 mg (n = 245), or placebo (n = 137). Induction study B was performed enrolling 689 patients; these patients were randomly assigned to receive filgotinib 100 mg (n = 285), filgotinib 200 mg (n = 262), or placebo (n = 142). As per findings, patients showed good tolerability towards filgotinib 200 mg; it was identified as efficacious in inducing and maintaining clinical remission compared with placebo in patients with moderately to severely active ulcerative colitis.