Maintenance therapy in acute myeloid leukemia: What is the future?

Relapse remains the primary obstacle to long-term survival in patients with acute myeloid leukemia (AML) who achieve a remission following standard induction and consolidation therapy. Although allogeneic hematopoietic stem cell transplantation decreases the risk of relapse for many patients, relapse is common even among these patients. A number of approaches to maintenance therapy for AML have been studied with the goal of finding an agent with a tolerable side effect profile that may be given to patients in remission, typically for a prolonged period of time, in order to decrease the risk of relapse. Numerous trials that evaluated cytotoxic agents as maintenance therapy did not find any improvement in survival, but more recent studies of alternative approaches to maintenance including immunomodulation, epigenetic reprogramming, and targeted agents have been much more promising. In this article, we review the current evidence for various maintenance strategies for AML including immunotherapy, hypomethylating agents, and targeted therapies, particularly FLT3 inhibitors. We also discuss promising emerging approaches to maintenance for AML, including the incorporation of measurable residual disease assessment.