This study is for people who were in a previous study with the drug **povorcitinib**. This drug is being checked for its safety and how well it works. Here are some important things to know: - **Eligibility**: You must have completed a previous **povorcitinib** study without problems and it must have helped you. You also need to follow study rules. - **Commitment**: The study needs you to not become pregnant or father a child during the study. You should also be ready to follow all study instructions. - **Exclusions**: If you had to stop the drug in the past due to safety, or took certain medicines or vaccines recently, you can't join. Pregnant or breastfeeding women are also not allowed. It's important to check your health and talk to your doctor to make sure you can join. Make sure to understand the study length, visits, and any risks or benefits before deciding. Note: This summary is for informational purposes only. Always consult with a healthcare professional before making decisions about medical participation.