The Efficacy and Safety of Cobitolimod in Participants With Moderate to Severe Active Left-Sided Ulcerative Colitis

Inclusion Criteria Induction: * Male or female ≥ 18 years of age. * Established diagnosis of UC. * Moderate to severe active left-sided UC assessed by central reading. * Have inadequate response, loss of response or be intolerant of at least one of the following treatments: Oral GCS, AZA/6-MP, Biologics, JAK-inhibitors, or other approved advanced therapies for UC. * Allowed to receive a therapeutic dose of the following UC drugs during the study: Oral GCS therapy (≤20 mg prednisone or equivalent/day) , Oral 5-ASA/SP compounds, AZA/6-MP. * Ability to understand the treatment, willingness to comply with all study requirements, and ability to provide informed consent. Exclusion Criteria Induction: * Suspicion of differential diagnosis. * Acute fulminant UC and/or signs of systemic toxicity. * UC limited to the rectum or extending beyond the splenic flexure. * Have failed treatment with more than three advanced therapies of two different therapeutic classes. * Have had surgery for treatment of UC. * History of malignancy, unless treated with no relapse of the disease and ≥ 5 years since last treatment (cured). * History or presence of any clinically significant disorder. * Concomitant treatment with cyclosporine, methotrexate, tacrolimus, or advanced therapies or similar immunosuppressants and immunomodulators. * Treatment with rectal GCS, 5-ASA/SP or tacrolimus. * Long-term treatment (\>14 days) with antibiotics or NSAIDs . * Serious known active infection including history o…