This is a study to test how well a new medicine, SAR443122, works for adults with ulcerative colitis (UC), a disease that causes swelling in the colon. It's a double-blind study, meaning neither the participants nor the doctors know who gets the medicine or a placebo (a fake treatment). The study has different groups trying different doses to find the best one. The study lasts up to 58 weeks, with 52 weeks of treatment and 6 weeks for screening and follow-up.

• The study includes a 12-week initial treatment and a 40-week maintenance phase. If the medicine helps, you can continue; otherwise, there's a chance to try a higher dose.
• Participants should have moderate to severe UC and meet specific health criteria.
• Excludes people with other diseases like Crohn's or certain infections.

Consider joining if you have been unsuccessful with other treatments and are willing to commit to the study's duration and requirements. Always discuss with your doctor before participating in any clinical trial to understand the risks and benefits fully.