Immune Therapies for Myelodysplastic Syndromes and Acute Myeloid Leukemia

SIMPLE SUMMARY: Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are bone marrow cancers that have a poor prognosis. They have traditionally been treated with chemotherapy with limited success, and stem cell transplant, which many patients are too frail to receive. Perturbations in the immune system play a role in the development of MDS and AML. Recently, there has been progress in understanding how the immune system can be harnessed to treat these cancers. Effective immune therapies for MDS and AML have been developed at a rapid pace, including novel immune checkpoint inhibitor antibodies, bispecific T-cell-engaging antibodies, antibody drug conjugates, vaccine therapies, and cellular therapeutics including chimeric antigen receptor T-cells and natural killer cells. This review article highlights advances in this field for the practicing clinician to aid in understanding new developments for treating patients with MDS and AML. ABSTRACT: Myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) are hematologic malignancies arising from the bone marrow. Despite recent advances in treating these diseases, patients with higher-risk MDS and AML continue to have a poor prognosis with limited survival. It has long been recognized that there is an immune component to the pathogenesis of MDS and AML, but until recently, immune therapies have played a limited role in treating these diseases. Immune suppressive therapy exhibits durable clinical responses in selected patients with MDS, but the question of which patients are most suitable for this treatment remains unclear. Over the past decade, there has been remarkable progress in identifying genomic features of MDS and AML, which has led to an improved discernment of the molecular pathogenesis of these diseases. An improved understanding of immune and inflammatory molecular mechanisms of MDS and AML have also recently revealed novel therapeutic targets. Emerging treatments for MDS and AML include monoclonal antibodies such as immune checkpoint inhibitors, bispecific T-cell-engaging antibodies, antibody drug conjugates, vaccine therapies, and cellular therapeutics including chimeric antigen receptor T-cells and NK cells. In this review, we provide an overview of the current understanding of immune dysregulation in MDS and AML and an update on novel immune therapies for these bone marrow malignancies.