- Patient has been administered any other systemic chemotherapeutic drug (including Gemtuzumab) within 21 days prior to trial enrollment and start of the conditioning regimen. Hydroxyurea is permitted if indicated to control induction refractory disease, and IT chemotherapy is allowed if indicated as maintenance treatment for previously diagnosed leptomeningeal disease, that has been in remission for at least 3 months prior to enrollment on this study.