This clinical trial is focused on studying the long-term safety and effectiveness of a medication called Upadacitinib in people with Ulcerative Colitis. Ulcerative Colitis is a chronic condition that causes inflammation and sores in the lining of the large intestine. The medication being tested, Upadacitinib, is a type of drug known as a Janus kinase (Jak) 1 inhibitor, which works by blocking certain enzymes in the body that are involved in the inflammatory process.

The purpose of this study is to evaluate how safe and effective Upadacitinib is over a long period. Participants in the study will take Upadacitinib in the form of a modified-release tablet, which means the medication is designed to be released slowly in the body. The study will also include a placebo group, which means some participants will receive a tablet that does not contain the active medication. This helps researchers compare the effects of the medication against no treatment.

Throughout the study, participants will be monitored regularly to assess any side effects and to see how well the medication is working in managing their Ulcerative Colitis symptoms. The study is designed to last for several years, allowing researchers to gather comprehensive data on the long-term use of Upadacitinib. Participants will have regular check-ups and assessments to ensure their safety and to track the progress of their condition.