Long-term remission of Philadelphia chromosome–positive acute lymphoblastic leukemia after allogeneic hematopoietic cell transplantation from matched sibling donors: a 20-year experience with the fractionated total body irradiation–etoposide regimen

Abstract

Abstract Allogeneic hematopoietic cell transplantation (HCT) is the only known curative modality for patients with Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ ALL). Sixty-seven patients with HLA-matched sibling donors received fractionated total body irradiation (FTBI) and high-dose VP16, whereas 11 patients received FTBI/VP16/cyclophosphamide, and 1 patient received FTBI/VP16/busulfan. The median age was 36 years. At the time of HCT, 49 patients (62%) were in first complete remission (CR1) and 30 patients (38%) were beyond CR1 (> CR1). The median follow-up was 75 months (range, 14-245 months). The 10-year overall survival for the CR1 and beyond CR1 patients was 54% and 29% (P = .01), respectively, and event-free survival was 48% and 26% (P = .02), respectively. There was no significant difference in relapse incidence (28% vs 41%, P = .28), but nonrelapse mortality was significantly higher in the beyond CR1 patients, (31% vs 54%, P = .03, respectively). By univariate analysis, factors affecting event-free and overall survival were white blood cell count at diagnosis (< 30 × 109/L vs > 30 × 109/L) and disease status (CR1 vs > CR1). The median time to relapse for CR1 and for beyond CR1 patients was 12 months and 9 months, respectively. Our results indicate that FTBI/VP16 with or without cyclophosphamide confers long-term survival in Ph+ ALL patients and that disease status at the time of HCT is an important predictor of outcome.