SIBERITE-1 - A phase iii, multicenter, double-blind, placebo-controlled, treat-through study to assess the efficacy and safety of induction and maintenance therapy with ro7790121 in patients with moderately to severely active crohn’s disease - ga45331

The purpose of this study is to assess the efficacy and safety of RO7790121 in patients with moderately to severely active Crohn’s Disease (CD). RO7790121 is a monoclonal antibody TL1A which plays a central role in the regulation of gut mucosal immunity and is involved in inflammatory bowel disease. A high unmet medical need remains for treatments with better benefit-risk profiles that provide sustained control to improve the long-term prognosis of patients with CD. In this study, patients will get either the study drug or placebo. Potential participants will undergo screening tests, and if deemed eligible to take part in the study, will be randomised to a treat. group; there will be a 2 out of 3 chance of being assigned to the study drug group. The treatment part of the study will have three phases: Induction Phase - Participants will receive treatment via IV infusion on the first day of the study, then 2 weeks later, and then every 4 weeks until Week 10. Maintenance Phase - Visits approx.every 4 wks. Treatment given via subcutaneous injection every 4 weeks from the 12th week until the 52nd week of the study at a dose of either 450mg or 150mg. Open-Label Extension Phase (optional) OLE - all participants will receive the study drug (including participants who previously were given placebo). If a participant decides not to take part in the open-label extension phase of the study, they will be asked to return for three more FU visits. During the OLE phase of the study, participants will continue to have study visits and receive the study drug treatment via SC injections (given under the skin) approx. every 2-4 weeks for approx. 5 years after the last patient is enrolled in the study. Participants may have the option of being seen at home for these visits.