Study of Nicotinamide with Oral Tetrahydrouridine and Decitabine for Sickle Cell Disease In this study, researchers are testing treatments for sickle cell disease (SCD), a condition where red blood cells are shaped like sickles, which can cause pain and other problems. They will try two medicines, nicotinamide and THU-decitabine, both alone and together. The study will last for 12 weeks for each medicine alone, and then 12 more weeks with both medicines combined. Participants can choose to continue for an extra 24 weeks with the combination treatment, totaling up to 48 weeks. Key Points:

• Duration: The study lasts up to 48 weeks, with optional extended treatment.
• Eligibility: Participants must be 18 or older, weigh at least 40kg, and have SCD.
• Exclusions: Those with recent severe infections, certain medical conditions, or ongoing treatments may not join.

This study is for adults with specific types of sickle cell disease who meet certain health criteria. Participants must not be pregnant, and those sexually active must use birth control. The study aims to find more effective treatments for sickle cell disease.