Cytoreductive treatment with clofarabine/ara-C combined with reduced-intensity conditioning and allogeneic stem cell transplantation in patients with high-risk, relapsed, or refractory acute myeloid leukemia and advanced myelodysplastic syndrome

The combination of cytoreductive chemotherapy with reduced‐intensity conditioning (RIC) is a highly effective antileukemic therapy. Purpose of this retrospective analysis was to evaluate the antileukemic efficacy and toxicity of clofarabine‐based chemotherapy followed by RIC and allogeneic stem cell transplantation (SCT) for high‐risk, relapsed, or refractory acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS). From May 2007 until October 2009, a total of 27 patients underwent allogeneic SCT after treatment with clofarabine and ara‐C for 5 d and RIC (4 Gy TBI/cyclophosphamide/ATG). Prophylaxis of graft‐versus‐host disease (GvHD) consisted of cyclosporine and mycophenolate mofetil. Unmanipulated G‐CSF mobilized PBSC (n = 26) or bone marrow cells (n = 1) were transplanted from unrelated (n = 21) or matched related (n = 6) donors. Non‐hematological toxicities of this regimen mainly affected liver and skin and were all reversible. Seven patients relapsed within a median time of 5.7 months. The overall survival (OS) and relapse‐free survival rates were 56% and 52% at 2 yr, respectively. In this cohort of patients, cytoreduction with clofarabine/ara‐C (ClAraC) followed by RIC allogeneic SCT was well tolerated and showed good antileukemic efficacy even in patients with high‐risk AML or MDS, with engraftment and GvHD‐incidence comparable to other RIC regimens.