Familial Haploidentical (FHI) T-Cell Depleted (TCD) with T-Cell Addback Stem Cell Transplantation for Patients with High-Risk Sickle Cell Disease (SCD) (IND 14359)

Allogeneic stem cell transplantation (AlloSCT) from HLA-matched unaffected sibling donors (MSD) has been successful for high-risk SCD, and is the only known curative therapy (Freed/Cairo et al, BMT, 2012). We have recently demonstrated 100% event free survival and absence of sickle cell symptoms following reduced toxicity conditioning and HLA matched sibling bone marrow or cord blood AlloSCT (Bhatia/Cairo et al, BMT, 2014). However, 5 out of 6 children who might benefit from this therapy lack an HLA matched family donor. Identifiable matched unrelated adult donors (URD) in this ethnic group are extremely limited and results from unrelated cord blood transplants are poor (Radhakrishnan K/Cairo et al., BBMT 2013, Kamani et al., BBMT, 2012). We previously demonstrated the use of positive CD34 selection followed by T cell add back (2 x 105 CD3/kg) from unrelated donors in pediatric recipients with both malignant and nonmalignant disease lead to 100% engraftment with minimal acute GVHD (aGVHD). In a high-risk FHI TCD thalassemia study, 16/22 cases engrafted without aGVHD and with 90% overall survival (Sodani et al., Blood, 2010). FHI TCD AlloSCT could expand the donor pool and improve outcomes for patients with high risk SCD.