Ruxolitinib-Enhanced Haplo HCT for Children and Young Adults With Sickle Cell Disease

While haplo HCT following a RIC regimen cures most patients with SCD, graft failure (GF) can occur and result in return of SCD. GF occurs more often in pediatric SCD patients and can be associated with significant morbidity and/or mortality. Development of strategies which reduce the risk of GF is needed to further improve haplo HCT outcomes for SCD, particularly in pediatric patients. This trial hopes to demonstrate that addition of ruxolitinib to a RIC regimen will reduce the incidence of GF without increasing conditioning-related toxicities. The RUX-HAPLO study is a Phase 1/2 single-arm, multi-center, open-label trial for pediatric and young adult patients undergoing haplo HCT for SCD. The study will enroll up to 24 participants over approximately 2 years. All participants will receive cytoreduction with hydroxyurea (HU) for at least 60 days (Day -70 to Day -10) prior to the start of conditioning. All participants will then receive a RIC regimen consisting of cyclophosphamide, fludarabine, thiotepa, ATG and TBI beginning on Day -9. Ruxolitinib will begin during conditioning and will continue post-HCT. Participants will also receive GVHD prophylaxis with post-transplant cyclophosphamide, in addition to sirolimus or a calcineurin inhibitor. The primary objective is to estimate 1-year event-free survival (EFS) with primary or secondary GF or death counting as events for this endpoint.