Inclusion Criteria:

1. Patient age 3-50 years old with refractory acute leukemia (primary refractory or
refractory relapse I or II) unresponsive to up to 2 salvage lines with a matched
donor (related or unrelated, matched defined as 8/8 HLA matching).

2. A donor willing and capable of donating peripheral blood stem cells and preferably
also bone marrow cells, and lymphocytes if indicated.

3. Each patient / patient's guardian must sign written informed consent.

4. Patients must have an ECOG PS ≤ 1; Creatinine <1.5 mg/dl; Ejection fraction >45%;
DLCO >70% of predicted; Serum bilirubin <2 mg/dl; elevated GPT or GOT < 2 x normal
values before transplant I.

Exclusion Criteria:

1. Not fulfilling any of the inclusion criteria.

2. In complete or very good partial remission.

3. Beyond 2nd relapse.

4. Received > 2 lines of salvage therapy.

5. Active CNS involvement of the leukemia

6. Active life-threatening infection.

7. Overt untreated infection.

8. HIV seropositivity, Hepatitis B or C antigen positivity with evidence of active
hepatitis.

9. Donor contraindication (HIV seropositive confirmed by Western Blot, Hepatitis B
antigenemia, HCV, evidence of bone marrow disease, unable to donate bone marrow or
peripheral blood due to concurrent medical condition).

10. Previous autologous or allogeneic stem cell transplantation.

11. Inability to comply with study requirements.