Stem Cell Transplant With Th2/Tc2 Cells to Treat Advanced Breast Cancer

Background: * In CC# 00-C-0119 we were able to demonstrate that allogeneic T cells could mediate a clinically relevant graft-versus-tumor (GVT) effect against MBC after a reduced-intensity, T cell depleted allogeneic hematopoietic stem cell transplant (alloHSCT). * Responses were observed after establishment of complete lymphoid chimerism, which was frequently delayed and required the use of planned donor lymphocyte infusions (DLI). DLI were associated with a significant incidence of graft-versus-host disease (GVHD). * In murine models, in vitro generated T cells of Th2/Tc2 phenotype can facilitate engraftment of HLA disparate allografts with significantly reduced GVHD as compared to T cell replete allografts that have not been manipulated. In addition, Th2/Tc2 cells provide an anti-tumor effect through the perforin/granzyme pathway. * Allogeneic Th2/Tc2 cells may facilitate rapid allo-engraftment post-transplant with reduced GVHD. In addition, the perforin-mediated anti-tumor activity of Th2/Tc2 cells should provide earlier benefit compared with T-cell depleted allografts. Objectives: -To determine the safety, as defined by the incidence of acute graft-versus-host disease, and feasibility of administering in vitro generated donor T cells of Th2/Tc2 phenotype to augment a T cell depleted allograft (T cell exchange) after reduced-intensity conditioning. Eligibility: * Patients with measurable, metastatic breast cancer and an HLA matched sibling donor * Patients must have received treatment with a taxane, an anthracycline, a hormonal agent and/or Herceptin, if the tumor expresses the respective receptors, and at least one treatment for metastatic disease that has not resulted in a complete response. Design: * Donors will initially have lymphocytes collected to generate the Th2/Tc2 product and then have blood stem cells collected following mobilization with filgrastim. The stem cell product will be T-cell depleted, and the T-cell dose will be adjusted to 1 x 10(5) CD3+ cells/kg. * Patients will receive induction (immune depleting) chemotherapy with the goal of reducing circulating CD4+ cell less than 50/microliter prior to proceeding to alloHSCT. * Patients will receive a reduced-intensity conditioning regimen consisting of fludarabine and cyclophosphamide. This will be followed by infusion of the T cell depleted allograft, which will be supplemented with Th2/Tc2 cells (i.e. T cell exchange). * Cyclosporine will be discontinued after 40 days to permit a full GVT effect. Patients may receive donor lymphocyte infusions at days +42, +70, +98 post-transplant to further potentiate a GVT effect. * Patients will be enrolled in three cohorts, with escalating Th2/Tc2 cell doses (0.5 - 12.5 x 10(7) cells/kg) given in a phase-I manner.