Ulcerative colitis (UC) is a disease that causes the large intestine and rectum to swell and bleed. This study is testing a new medicine called lutikizumab, given through a vein (IV) or under the skin (SC), to see if it helps adults with UC. It will compare lutikizumab to another medicine called adalimumab. The study will check for any side effects and how the disease changes.

Participants will be put into different groups. Some will get lutikizumab and others will get adalimumab for 12 weeks. If they respond well to lutikizumab, they will continue with it for up to 52 weeks. If they respond to adalimumab, they will keep getting it for the same period. Those who don't respond will switch to lutikizumab.

• Study Length: Up to 52 weeks.
• Regular hospital or clinic visits required.
• 200 participants from around the world will join.

Participants must have had UC for at least 90 days and show an unsatisfactory response to certain medications. They cannot join if diagnosed with Crohn's disease or have only rectal inflammation.