Sequential chemotherapy followed by reduced-intensity conditioning and allogeneic haematopoietic stem cell transplantation in adult patients with relapse or refractory acute myeloid leukaemia: a survey from the Acute Leukaemia Working Party of EBMT.

This study analysed the outcome of 267 patients with relapse/refractory acute myeloid leukaemia (AML) who received sequential chemotherapy including fludarabine, cytarabine and amsacrine followed by reduced-intensity conditioning (RIC) and allogeneic haematopoietic stem cell transplantation (HSCT). The transplants in 77 patients were from matched sibling donors (MSDs) and those in 190 patients were from matched unrelated donors. Most patients (94·3%) were given anti-T-cell antibodies. The incidence of acute graft-versus-host disease (GVHD) of grades II-IV was 32·1% and that of chronic GVHD was 30·2%. The 3-year probability of non-relapse mortality (NRM) was 25·9%, that of relapse was 48·5%, that of GVHD-free and relapse-free survival (GRFS) was 17·8% and that of leukaemia-free survival (LFS) was 25·6%. In multivariate analysis, unrelated donor recipients more frequently had acute GVHD of grades II-IV [hazard ratio (HR) = 1·98, P = 0·017] and suffered less relapses (HR = 0·62, P = 0·01) than MSD recipients. Treatment with anti-T-cell antibodies reduced NRM (HR = 0·35, P = 0·01) and improved survival (HR = 0·49, P = 0·01), GRFS (HR = 0·37, P = 0·0004) and LFS (HR = 0·46, P = 0·005). Thus, sequential chemotherapy followed by RIC HSCT and use of anti-T-cell antibodies seems promising in patients with refractory AML.