Inclusion Criteria:

- primary refractory or relapsed AML

- confirmed diagnosis of AML (de novo or secondary) as defined by WHO classification
(Vardiman 2002)

- aged at least 18 years

Exclusion Criteria:

- initial diagnosis of acute promyelocytic leukemia as defined by
French-American-British criteria (Bennett 1976)

- patient in blast crisis stage of chronic myeloid leukemia

- received high-dose cytarabine (total cumulative dose of >6g/m sq)in last 6 months

- interval of <6 months between first onset of last complete remission and current
relapse

- those with primary refractory leukemia who have received more than three previous
induction cycles

- relapsed patients who have received more than three previous treatment regimens