A Study to Investigate the Efficacy of LT-02 in Patients With Mesalazine Refractory Ulcerative Colitis

Inclusion Criteria: * Men and women 18 years or older who have given written Informed Consent * Patients with proven ulcerative colitis * Active disease course for the last 6 weeks or longer with bloody diarrhea * Patients with an inadequate response to a treatment with mesalazine or a documented intolerance to mesalazine. Exclusion Criteria: * Infectious colitis, including cytomegalovirus or Clostridium difficile induced colitis, * Crohn's disease, * Colitis due to other reasons than ulcerative colitis like known diverticulitis, radiation colitis, ischemic colitis, microscopic colitis, or indeterminate colitis, * Treatment with other investigational medicinal product within 3 months prior to study entry