Allogeneic Natural Killer (NK) Cells in Patients With Advanced Metastatic Breast Cancer

We believe that administration of related allogeneic (donor) natural killer cells along with IL-2, rather than autologous natural killer cells will provide the most effective anticancer therapy in this setting, and wish to test this approach. To do this, we will select a related donor who is partially HLA-matched with the study subject, to increase the likelihood that donor natural killer cells will kill the subject's cancer cells. We will also give chemotherapy drugs to increase the subject's tolerance for the donor natural killer cells. We will test the use of donor natural killer (NK) cell infusions. The immune system has a special way that it sees and identifies cancer cells or foreign agents (like viruses). The subject's own NK cells may not attack their cancer because NK cells see the tumor cells as "self" (a coating on the cell surface identifies a cell as "self" or "non-self"). We have reason to believe that NK cells may not kill cancer cells because NK cells have special receptors that "turn them off" when they encounter cancer cells (by seeing them as "self"). We may be able to get around this problem by using donor NK cells. Finally, subjects will receive a dose of subcutaneous IL-2 3 times a week (for 2 weeks) which has been proven safe in our previous studies to stimulate the natural killer cells.