Patients undergo bone marrow aspirate and biopsy to assess response. Patients with a major hematological improvement OR with grade 3-4 hematological toxicities during the first 2 courses of therapy AND/OR ≥ 50% reduction in bone marrow cellularity compared to baseline proceed to optimization therapy A. Patients not meeting any of the above criteria proceed to optimization therapy B. Patients with disease progression are removed from study.