Feasibility of an intensified myeloablative conditioning regimen consisting of busulfan, fludarabine, cytarabine, and total body irradiation before single cord blood transplantation in elderly patients

The optimal conditioning regimen for stem cell transplantation in elderly patients remains to be established. We developed a novel preparative regimen using fludarabine 180 mg/m 2 , intravenous busulfan 12.8 mg/m 2 , cytarabine 8 g/m 2 , and 4-Gy total body irradiation before cord blood transplantation (CBT) in patients older than 55 years with various hematological malignancies. All but one patient received graft-versus-host disease (GVHD) prophylaxis consisting of cyclosporine (CsA) and short-term methotrexate (sMTX). Thirty-three patients were included in this study, with a median age of 64 years (range 56–70). The disease risk index was high or very high in 67% of patients, and 73% had a disease status other than complete remission. The probabilities of overall survival and disease-free survival at 3 years were 60 and 57%, respectively. The cumulative incidences of relapse and non-relapse mortality at 3 years were 18 and 25%, respectively. Regimen-related toxicities were generally tolerable. Disease-free survivors ( n = 20) stopped immunosuppressants at a median of 7.4 months (range 2.6–25.0), in all cases by the time of the last follow-up. In conclusion, this highly myeloablative conditioning regimen resulted in a high probability of disease-free, GVHD-free, immunosuppressant-free survival after single CBT. (190 words)