Atreya R, Peyrin-Biroulet L, Klymenko A, et al. - In patients with moderate-to-severe, left-sided ulcerative colitis, the effectiveness and safety of different dose regimens of cobitolimod as induction therapy were evaluated. Researchers performed a randomized, double-blind, five-arm, placebo-controlled, dose-ranging phase 2b study. From 91 hospitals or outpatient clinics in 12 European countries, they enrolled patients with moderate-to-severe, left-sided ulcerative colitis who had an inadequate response to conventional or biological therapies. They randomized a total of 213 patients between June 30, 2017 and June 26, 2019 to different dosing regimens of cobitolimod and placebo. In comparison with placebo, two topical administrations of cobitolimod 250 mg were well tolerated and more effective in inducing clinical remission 6 weeks following the start of treatment. Toll-like receptor 9 activation was found to be a promising novel therapeutic target in ulcerative colitis and needs further evaluation, with phase 3 trials of cobitolimod planned.