B-Cell ALL, Childhood

This trial will assess the feasibility of alpha/beta T-cell and B-cell depleted allogeneic hematopoietic cell transplantation (HCT) followed by blinatumomab therapy for high-risk B cell acute lymphoblastic leukemia (ALL) as a means of reducing rates of subsequent relapse and improving survival, while also minimizing treatment-related morbidity/ mortality and late effects. The conditioning regimens will be dependent on the patient's minimal residual disease (MRD) status prior to HCT using high throughput sequencing.