Dose-reduced conditioning for allografting in 44 patients with chronic myeloid leukaemia: a retrospective analysis

This retrospective study describes the outcome of patients with chronic myeloid leukaemia after allografting using dose-reduced conditioning with fludarabine and busulphan. Forty-four Philadelphia chromosome (Ph)-positive patients were transplanted in nine German centres; 26 patients were in chronic phase, 11 in accelerated phase and seven in blast crisis. Thirty-four patients achieved complete remission, with 18 alive and disease-free at a median follow-up of 562 d (range 244-922 d). Grade II-IV acute graft-versus-host disease (GVHD) incidence was 43%. Twenty patients died, 15 of causes unrelated to relapse. Risk factors predisposing to graft failure by univariate analysis were an unrelated donor (8/23 compared with a related donor 2/21, P = 0.07) and interferon therapy within 90 d of transplant (4/6 versus 3/17, P = 0.025). At the last follow-up, of 31 patients for whom molecular or cytogenetic data were available, 16 (52%) were polymerase chain reaction-negative, and seven (23%) were Ph-negative by fluorescent in situ hybridization. These findings demonstrate that dose-reduced conditioning with fludarabine and busulphan provides durable engraftment and a low rate of relapse. However, in this population, many of whom were not eligible for high-dose conditioning due to age, reduced performance status, previous complications or extensive pre-treatment, these data highlight the need for effective anti-infectious and GVHD prophylaxis. In addition, this study supports the discontinuation of interferon therapy at least 90 d before transplant