Fludarabine, Busulfan, Antithymocyte Globulin, and Total Body Irradiation for Pretransplantation Conditioning in Acute Lymphoblastic Leukemia: Excellent Outcomes in All but Older Patients with Comorbidities

Hematopoietic stem cell transplantation (SCT) is routinely offered to suitable candidates with high-risk or advanced acute lymphoblastic leukemia (ALL). In this report, we update our experience with SCT in patients with ALL with a novel conditioning regimen. A total of 44 patients with high-risk or advanced (greater than first complete remission) ALL in remission underwent SCT after myeloablative conditioning with fludarabine + busulfan + total body irradiation. The median follow-up of surviving patients was 4.3 years (range, 1.0-9.0 years). The cohort consists of 32 patients with high-risk disease (median age, 40 years; range, 19-64 years) and 12 patients with advanced disease (median age, 25 years; range, 19-65 years) who underwent SCT: 25 with a related donor (21 fully matched) and 19 with an unrelated donor (16 fully matched). The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) was 53.2%, and that of grade III-IV acute GVHD was 20.6%. The incidence of chronic GVHD was 55%. The 100-day nonrelapse mortality was 13.6%. Five-year progression-free survival was 56.7%, and 5-year overall survival was 66.0%. Nine patients (20%) died in remission, 6 (14%) died after relapse, and 2 survived after a second SCT for relapsed disease. Outcomes were inferior in older patients with comorbidities compared with other patients.