Fractionated doses of gemtuzumab ozogamicin with escalated doses of daunorubicin and cytarabine as first acute myeloid leukemia salvage in patients aged 50-70-year old: a phase 1/2 study of the acute leukemia French association.

This Phase 1/2 study aimed to determine optimal doses of daunorubicin (DNR; mg/m(2)) and cytarabine (mg/m(2)) to be combined with fractionated doses of gemtuzumab ozogamicin (GO, Mylotarg(®); 3 mg/m(2) on day 1, 4, and 7) satisfying safety requirements. Three dose levels of DNR/AraC were investigated namely (45, 100), (60, 100), and (60, 200). Patients included were acute myeloid leukemia in first relapse, aged 50-70 years. Hematological recovery was 31 days for neutrophil and 32 days for platelet counts. A documented infectious episode > Grade 2 occurred in 11/20 patients (55%). None of the 20 patients had signs of veno-occlusive disease. Overall, eleven patients reached complete remission (CR), two CR with incomplete platelets recovery. The results showed that combination of fractionated GO doses with DNR at 60 mg/m(2)/d for 3 days and cytarabine at 200 mg/m(2)/d for 7 days is tolerable and could be further investigated in the front-line therapy.