6-Thioguanine, Cytarabine, and Daunorubicin (TAD) and High-Dose Cytarabine and Mitoxantrone (HAM) for Induction, TAD for Consolidation, and Either Prolonged Maintenance by Reduced Monthly TAD or TAD-HAM-TAD and One Course of Intensive Consolidation by Sequential HAM in Adult Patients at All Ages With De Novo Acute Myeloid Leukemia (AML): A Randomized Trial of the German AML Cooperative Group

Abstract

Purpose: To examine the efficacy of prolonged maintenance chemotherapy versus intensified consolidation therapy for patients with acute myeloid leukemia (AML). Materials and Methods: Eight hundred thirty-two patients (median age, 54 years; range, 16 to 82 years) with de novo AML were randomly assigned to receive 6-thioguanine, cytarabine, and daunorubicin (TAD) plus cytarabine and mitoxantrone (HAM; cytarabine 3 g/m2 [age < 60 years] or 1 g/m2 [age ≥ 60 years] × 6) induction, TAD consolidation, and monthly modified TAD maintenance for 3 years, or TAD-HAM-TAD and one course of intensive consolidation with sequential HAM (S-HAM) with cytarabine 1 g/m2 (age < 60 years) or 0.5 g/m2 (age ≥ 60 years) × 8 instead of maintenance. Results: A total of 69.2% patients went into complete remission (CR). Median relapse-free survival (RFS) was 19 months for patients on the maintenance arm, with 31.4% of patients relapse-free at 5 years, versus 12 months for patients on the S-HAM arm, with 24.7% of patients relapse-free at 5 years (P = .0118). RFS from maintenance was superior in patients with poor risk by unfavorable karyotype, age ≥ 60 years, lactate dehydrogenase level greater than 700 U/L, or day 16 bone marrow blasts greater than 40% (P = .0061) but not in patients with good risk by complete absence of any poor risk factors. Although a survival benefit in the CR patients is not significant (P = .085), more surviving patients in the maintenance than in the S-HAM arm remain in first CR (P = .026). Conclusion: We conclude that TAD-HAM-TAD-maintenance first-line treatment has a higher curative potential than TAD-HAM-TAD-S-HAM and improves prognosis even among patients with poor prognosis.