Unrelated donor and autologous marrow transplant therapy of chronic myelogenous leukemia (CML)

Marrow transplant from an HLA-matched sibling donor can cure CML. Best results are observed when patients are transplanted early in chronic phase. T-lymphocyte depletion of donor marrow can effectively prevent chronic graft versus host disease, but is associated with a high incidence of relapse. Hematologic relapse after marrow transplantation can be treated successfully with alpha-interferon, donor buffy coat cells or second transplant. HLA phenotypically matched and, in some cases, 1 HLA antigen mismatched unrelated donors can also be used successfully for marrow transplantation therapy of CML. Complications include an increased incidence of graft failure and graft vs. host disease. Chronic phase patients transplanted early in the disease course have the best outcome. The development of the National Marrow Donor Program in the United States and a network of donor registries throughout the world as well as the establishment of new techniques for histocompatibility testing will increase the availability of unrelated donors and expedite the donor search process. Autologous marrow transplantation can induce complete hematologic and cytogenetic remissions and may prolong survival when compared with results expected from conventional therapy for CML. Strategies are being developed to obtain benign primitive progenitors suitable for autologous marrow transplantation by positive selection techniques and to develop further post-transplant anti-leukemia cell therapy to use as an adjunct to autologous marrow transplantation for CML.