High-dose etoposide, cyclophosphamide and total body irradiation with allogeneic bone marrow transplantation for resistant acute myeloid leukemia: a study by the North American Marrow Transplant Group.

We evaluated the toxicity and efficacy of high-dose etoposide, cyclophosphamide and total body irradiation (TBI) followed by allogeneic bone marrow transplantation (BMT) for patients with resistant, acute myeloid leukemia (AML). Between 9/84 and 11/92 we treated 70 patients with etoposide (900-1800 mg/m2), cyclophosphamide (120-180 mg/kg) and TBI (1000-1200 cGy) followed by allogeneic BMT from histocompatible siblings. Forty patients were in untreated first relapse. Median time from diagnosis to transplant was 10 months. Toxicity was similar to that observed with cyclophosphamide/TBI with the median duration of neutropenia (ANC < 500/microliters) being 19 days (range 10-27) and the median duration of thrombocytopenia being 23 days (range 13-173). Twenty-three patients remain in continuous complete remission at a median of 56 months after transplant (range 36-132 months). Probabilities of disease-free survival, persistent/recurrent disease and transplant related mortality are .32, .47, and .37 respectively. Multivariate analysis indicated that grade > or = 2 acute graft-vs-host disease and transplant in untreated first relapse were associated with increased DFS due to reduced relapse risk. We conclude that high-dose etoposide with cyclophosphamide and TBI followed by allogeneic BMT is effective therapy for resistant AML, producing durable remission in approximately one-third of those treated. Disease persistence or recurrence was the major cause of treatment failure. Further improvement in DFS following allogeneic BMT for resistant AML might be achieved by using less intensive GVHD prophylaxis or through infusion of donor peripheral blood cells in patients who fail to develop significant acute GVHD.