Mini Allo Stem Cell Transplantation for the Treatment of Solid Tumors

The trial is a pilot study in which patients with metastatic solid tumors will undergo non-myeloablative allogeneic hematopoietic stem cell transplantation. Patients whose immunosuppressive therapy has been tapered off, are without GVHD, and have evidence of residual or progressive disease will undergo DLI.

In recent years there have been attempts to harness the graft-versus-tumor effect of allogeneic bone marrow transplant to treat patients with metastatic solid tumors. Researchers at the NIH recently reported on 19 patients with refractory metastatic renal-cell carcinoma who had suitable donors and received a preparative regimen of cyclophosphamide and fludarabine followed by an infusion of a peripheral-blood stem-cell allograft from an HLA-identical sibling or a sibling with a mismatch of a single HLA antigen.49 They note that at the time of the last follow-up, 9 of the 19 patients were alive 287 to 831 days after transplantation (median follow-up: 402 days). Two had died of transplantation-related causes and 8 of progressive disease. In 10 patients (53%) metastatic disease regressed: 3 had a complete response, and 7 had a partial response. The patients who had a complete response remained in remission 27, 25, and 16 months after transplantation. Regression of metastases was delayed, occurring a median of 129 days after transplantation, and often followed the withdrawal of cyclosporine and the establishment of complete donor T-cell chimerism. They concluded that these results were consistent with a graft-versus-tumor effect and that non-myeloablative allogeneic stem cell transplantation can induce sustained regression of metastatic RCCA in patients who have had no response to conventional immunotherapy.