Hypomethylating agents and other novel strategies in myelodysplastic syndromes

Over the last decade, treatment approaches for patients with myelodysplastic syndromes (MDS) have improved significantly. Treatment of MDS is tailored to the specific risk characteristics of the patient. In general, patients are divided into lower- and higher-risk categories. Without therapy, prognosis of patients with higher-risk MDS is poor, and treatments should be directed to improve survival. Prognosis of patients with lower-risk MDS is more heterogeneous, and therapies are usually directed to minimize transfusion needs and potentially to alter the natural course of the disease. Treatment options for patients with higher-risk MDS include hypomethylating agents (azacitidine and decitabine), intensive chemotherapy (ICT), and allogeneic stem-cell transplantation (alloSCT). The use of the hypomethylating agents has transformed the approach to this patient population, in particular older individuals, for whom ICT and alloSCT are not an option. In lower-risk MDS, treatment strategies are used sequentially and usually include observation in patients with low risk and no transfusion dependency, growth factors, and lenalidomide for patients with alteration of chromosome 5 and anemia. The use of hypomethylating agents is less understood in this group of patients. AlloSCT is usually reserved for patients with lower-risk MDS closer to the time of transformation. In this short review, we discuss treatment alternatives for patients with MDS and delineate some of the ongoing challenges, including the development of better front-line strategies for patients with higher-risk disease, the concept of altering the natural course of the disease in lower-risk MDS, and the development of new treatment approaches for patients who do not benefit from hypomethylating agents.