Cyclophosphamide, cytosine arabinoside and TBI as a conditioning regimen for allogeneic bone marrow transplantation in patients with leukemia

This is a prospective study designed to determine the toxicity, efficacy an d antileukemic effect of high-dose cytosine arabinoside (ara-C), cyclophosp hamide and total body irradiation (TBI) as a myeloablative regimen prior to allogeneic bone marrow transplantation for patients with hematologic malig nancies. Fifty-eight patients with hematologic malignancies were treated wi th cyclophosphamide, high-dose ara-C and total body irradiation (TBI) follo wed by allogeneic bone marrow transplantation. Fifty patients had good prog nosis disease and eight had poor prognosis disease, Cyclosporine and short- course methotrexate were used for graft-versus-host disease (GVHD) prophyla xis, The conditioning regimen consisted of ara-C 3000 mg/m(2) twice a day x six doses an days -7, -6, and -5; cyclophosphamide 1800 mg/m(2) on days -4 and -3; and TBI 1400 cGy mid-line dose at 5 cGy/min in eight total fractio ns administered twice a day on days -4, -3, -2, and -1, The bone marrow was infused on day 0 (zero), Toxicity related to the conditioning regimen was comparable to that reported with other conditioning regimens, except for di arrhea which appears to be more frequent, The actuarial survival at 1 year was 69% (58-82) and at 5 years was 54% (42-69) with the numbers in parenthe ses representing the 95% confidence interval of the Kaplan-Meier estimate, After a median follow-up of 28 months, 31 of 58 (53%) patients are alive wi thout evidence of disease. Only four of the 58 patients (7%) have relapsed, Cyclophosphamide, ara-C and TBI is a safe and effective myeloablative regi men for patients with leukemia. The overall relapse rate in our study was 7 % with a median follow-up of 28 months and appears to be lower than relapse rates reported in other series, This is probably-due to the added antileuk emic effect of ara-C, This regimen should be compared with other myeloablat ive regimens in a controlled study.