Based on guidance from the FDA and EMA, the phase III program for cobitolimod will consist of two sequential induction studies and a yearlong maintenance study with patients that have responded to cobitolimod as induction therapy. The phase III program will form the basis for marketing approval by confirming cobitolimod’s overall efficacy and safety profile in a large enough group of patients with moderate to severe, left-sided ulcerative colitis with an inadequate response or failure to tolerate conventional therapy, biological therapy or JAK inhibitors. The important initial CONCLUDE study is a randomised, double-blind, placebo-controlled induction study that will include approximately 440 patients. The primary endpoint will be clinical remission at week 6, which is the same primary endpoint as used in the successful phase IIb study CONDUCT. Apart from the dosing 250 mg given at baseline and week 3, which was the highest dose and the one that showed the best efficacy in the phase IIb study, the phase III study will also evaluate a higher dose, 500 mg, in an adaptive study design. Patients responding to cobitolimod in the induction study will be eligible to continue in the one-year maintenance study, where they will be treated with either cobitolimod or placebo once every three weeks.