Selection of optimal remission consolidation therapy for individual patients with acute myelogenous leukemia

Prior to the initiation of remission induction therapy patients with AML a combination of 13-cis retinoic acid and a interferon was administered for 3 days with measurement of the % leukemia cells in S phase prior to and after the administration of these two agents. Patients then received remission induction therapy consisting of idarubicin on days 1, 2, 3 and cytarabine on days 1–7. Patients whose leukemia entered CR [66%] received 3 courses of remission consolidation therapy with courses #s 1 and 3 being identical to remission induction therapy and course #2 consisting of cytarabine 2 gm/m 2 q 12 h on days 1–4. Patients received a combination of retinoic acid and a interferon between each course of remission consolidation therapy. 44% of patients remain in remission at 5 years. 69% of leukemias with intermediate cytogenetic characteristics and with a LI less than the median value prior to the 3 day administration of RA/IFN are in remission at 5 years while the same is the case for 26% of leukemias whose LI was greater than the median value. Considering the post RA/IFN LI, 88% of intermediate cytogenetic leukemias with a LI less than the median value are in remission at 5 years. 76% of leukemias with favorable cytogenetic characteristics are in remission at 5 years. Leukemias with these cytogenetic characteristics have low % cells in S phase. Leukemias with favorable cytogenetic characteristics or with intermediate cytogenetic characteristics and a low % S phase cells constitute 48% of newly diagnosed standard prognosis AML. When treated with the remission consolidation regimen described here these patients have a 76% to 88% likelihood of being in remission beyond 5 years. Studies are underway to determine if a reduction of the LI of cytogenetic intermediate AML whose LI exceeds the median value will result in a prolongation of the remission durations of these patients.