- During dose escalation, patients must have received at least one prior therapy, need additional cytoreduction, and meet criteria for relapsed or refractory disease; relapsed disease is defined as a patient who previously achieved a CR or a PR, but after a period of six or more months demonstrates evidence of disease progression; refractory disease is defined as progression within six months of the last anti-leukemic therapy, or any response less than a CR or PR; patients who are previously untreated, and do not wish to receive chemotherapy or immunotherapy, are eligible for the dose expansion portion of the study