Nonmyeloablative Allogeneic Stem Cell Transplantation for Chronic Myelogenous Leukemia in the Imatinib Era

Allogeneic stem cell transplantation (ASCT) is a potentially curative treatment for patients with chronic myelogenous leukemia (CML) and was previously considered the preferred treatment for newly diagnosed CML. The success of imatinib has changed treatment recommendations, and allogeneic transplants are now reserved for imatinib treatment failures. Previous imatinib treatment does not compromise the results of ASCT, but patients with overt transformed disease have poor results. It is unclear whether patients whose disease is considered to have failed imatinib should be referred immediately for ASCT or receive treatment with a second-generation tyrosine kinase inhibitors (TKI). Patients whose disease fails 2 TKIs should receive ASCT if possible. Nonmyeloablative preparative regimens reduce the toxicity and treatment-related mortality associated with the transplantation procedure and allow transplantations to be performed in older and medically infirm patients. This approach, including posttransplantation treatment with TKIs and donor lymphocyte infusion, produces a high fraction of durable molecular complete remissions.