This study is for kids and young adults with sickle cell disease (SCD), a condition where red blood cells are shaped like sickles and can cause pain and other problems. The study will test if a drug called ruxolitinib helps make bone marrow transplants work better. A bone marrow transplant is when healthy blood cells are put into someone’s body to help them get better. The study will last 4 years, with 2 years for enrolling 24 participants and 2 more years for follow-up.

Before the transplant, participants will get medicine to prepare their bodies. After the transplant, they will continue to take ruxolitinib. The study wants to see if this helps reduce graft failure (GF), which is when the transplant doesn’t work and the SCD comes back.

• Length: 4 years total (2 years enrolling, 2 years follow-up).
• Visits: Regular check-ups and follow-ups post-transplant.
• Risks: Potential side effects from medicines and transplant process.

Participants must have SCD and a relative who can donate bone marrow. They shouldn’t have certain infections or conditions. Pregnant individuals or those in another drug trial recently cannot join.