HIGH-DOSE ETOPOSIDE, CYCLOPHOSPHAMIDE, AND TOTAL-BODY IRRADIATION WITH ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR PATIENTS WITH ACUTE MYELOID-LEUKEMIA IN UNTREATED FIRST RELAPSE - A STUDY BY THE NORTH-AMERICAN MARROW TRANSPLANT GROUP

Relapse is a major cause of treatment failure following allogeneic bone marrow transplantation (BMT) for acute myeloid leukemia (AML). To reduce the risk of relapse following BMT for patients with hematologic malignancy, our group developed a novel preparative regimen which combines high-dose etoposide with cyclophosphamide and total body irradiation (VPCyTBI). We now report the outcome of therapy with VPCyTBI followed by allogeneic BMT for 40 patients with AML in untreated first relapse. With the exception of increased stomatitis, the toxicity of this regimen was similar to that reported by others for CyTBI. Forty-four months after transplant the actuarial probabilities of disease-free survival (DFS), persistent or recurrent leukemia, and transplant related mortality were .29, .44, and.47 respectively. DFS was improved (P < .01) and risk of persistent or recurrent leukemia reduced (P = .005) among patients with significant (grade greater than or equal to 2) acute GVHD. Patients with 30% or more blasts on pre-BMT bone marrow examination were not at increased risk for persistent or recurrent leukemia. We conclude that VPCyTBI with allogeneic BMT is effective therapy for AML in untreated first relapse and that a randomized trial comparing this regimen with CyTBI is warranted. (C) 1995 by The American Society of Hematology.