Abstract: The present invention encompasses methods for reducing the number of target cells in a subject, such as cancer cells. The methods include administration of genetically-modified human immune cells expressing a chimeric antigen receptor or exogenous T cell receptor, which have specificity for an antigen on the target cells. Administration of the genetically-modified immune cells is preceded by the administration of a tolerance regimen, followed by administration of a lymphodepletion regimen, to improve efficacy of the therapy and persistence of the cells in vivo.

Abstract: A lymphocytotoxic, but hematopoietic stem cell-sparing, high-dose amount of an oxazaphosphorine drug such as, for example, cyclophosphamide, administered post-transplantation can be used to reduce transplant rejection, including graft-versus-host-disease (GVHD). In some embodiments, the transplants are bone marrow transplants or hematopoietic stem cell transplants carried out for the treatment of hematologic disorders, including hematologic malignancies and non-malignant hematologic disorders. In some embodiments, the transplants are carried out for the treatment of hereditary hemoglobinopathies, such as sickle cell anemia and thalassemia.