Patients with refractory and relapse leukemia had poor outcome even with allogeneic stem cell transplantation. In our previous retrospective study, the overall survival is 14.6+/-8.8% while 90% patients eventually relapsed with marrow ablative conditioning mostly standard iv-Bu-Cy or Cy-TBI. The accumulated TRM is 29.5+/-11.5%. Thus our data suggested that the conventional transplantation approach may not be able to overcome the refractory disease. A new strategy to combined a low dose regimen following intensive chemotherapy for tumor reduction seems to be effect in both relapsed. high-risk and refractory AML or ALL. In this study, we focus on a new treatment strategy for particular refractory AML patients.

This is a single arm phase II trial to test the efficacy and feasibility of new sequential intensive chemo and transplantation approach for refractory leukemia. Patients with refractory acute myeloid or lymphoblastic leukemia are enrolled in this trial. Patients will received intensive chemotherapy including Fludarabine, cytarabine and idarubicin as (FLAG-IDA). Seven days after the chemotherapy, sequential transplantation conditioning regimen as fludarabine and busulfan will be given.

Inclusion Criteria:

• adult patients with refractory or relapse acute myeloid leukemia not in remission after 2 cycles of induction chemotherapy early relapse (1st remission less than 6 months) not in remission after 1 cycle of re-induction chemotherapy multiple relapse
• age 16-60 years
• with inform consent
• no contraindication for allogeneic transplantation: active infection, allergy to FLu/Bu/CTX, liver and renal function damage
• HLA matched related (6/6) or unrelated donors (at least 8/10)

Exclusion Criteria:

• age less than 18 years or over 61 years
• liver function/renal function damage (over 2 X upper normal range)
• with mental disease