A randomized comparison of intensive maintenance treatment for adult acute myelogenous leukemia using either cyclic alternating drugs or repeated courses of the induction-type chemotherapy: AML-6 trial of the EORTC Leukemia Cooperative Group

Maintenance Therapy in AML

Recent advances in therapeutics coupled with steady improvements in supportive care for patients with acute myeloid leukemia (AML) have led to improved outcomes. Despite these advances, even in patients that achieve a complete remission with initial therapy high rates of relapse remain a clinical dilemma. For decades, investigators have attempted strategies of maintenance therapy to prolong both remission duration and overall survival in patients with AML. These approaches have included cytotoxic chemotherapy, immunotherapy, hypomethylating agents, and targeted small molecule therapy. Overall, the evidence in favor of maintenance therapy is limited. Recent strategies, especially with hypomethylating agents have begun to show promise as maintenance therapy in improving clinical outcomes. Ongoing and future studies will continue to elucidate the true role for maintenance therapy options in patients with AML. In this review we summarize prior and ongoing maintenance therapy approaches in AML and highlight some of the most promising strategies.

Cytosine arabinoside in the treatment of acute myeloid leukemia: the role and place of high-dose regimens

Cytosine arabinoside (AraC) is one of the most active drugs in the treatment of acute leukemias and is widely applied at all phases of therapy. In spite of extensive clinical and experimental investigations, its intracellular metabolism and especially its mechanism of action are still not fully elucidated. Controversy also continues about the most appropriate way and dose of administration; which differs by more than 100 fold in clinical studies ranging from low-dose, over standard and intermediate dose regimens, to high-dose protocols. The present review is focused on the role and place of high-dose AraC treatment in acute myeloid leukemia (AML). Based on available clinical and experimental data, the following conclusions can be drawn: Not considering possible but not yet demonstrated beneficial long-term effects, the incorporation of high-dose AraC into induction therapy has not resulted in an improvement of overall remission rate, with the possible exception of patients with slow initial cytoreduction after a first course of conventional treatment. Promising results, however, emerge from high-dose AraC-based consolidation protocols, which need confirmation in prospectively randomized comparative trials. In relapsed and refractory AML, higher than conventional doses undoubtedly enhance the efficacy of AraC salvage therapy. The question of whether the antileukemic activity of intermediate-dose regimens with 500-1,000 mg/m2 AraC is equivalent to that of high-dose protocols applying 2,000-3,000 mg/m2 AraC, however, remains open but may soon be answered by ongoing controlled clinical and pharmacologic investigations.