Established and novel agents for myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are the most commonly diagnosed myeloid malignancy, with >15 000 new cases identified in the United States yearly. Prognostic scoring systems supplant a formal staging approach and, in general, divide patients into those with lower-risk and those with higher-risk MDS. Although treatment goals for patients with lower-risk disease focus on minimizing transfusions and optimizing quality of life, in higher-risk MDS, the goal is to delay transformation to acute leukemia and to prolong survival. In lower-risk patients, isolated cytopenias are treated with erythropoiesis-stimulating agents or growth factors such as thrombopoietin mimetics. For patients with the del(5q) cytogenetic abnormality or those who fail these initial approaches, lenalidomide may be tried, as can experimental agents. Lower-risk patients with multiple cytopenias may be treated with immunosuppressive drugs or low-dose hypomethylating agents. For patients with higher-risk disease, hypomethylating agents are the preferred initial treatment approach, with evaluation for hematopoietic cell transplantation at diagnosis. Several novel agents are being developed for MDS patients who have failed hypomethylating drugs.