Supportive care, growth factors, and new therapies in myelodysplastic syndromes

Treatment of myelodysplastic syndromes (MDS) has evolved to encompass a broad spectrum of therapies aiming to inhibit apoptosis, promote hemopoiesis, and reduce proliferation of clonal immature cells. A small but expanding cohort of patients with MDS may be cured, but for the majority the aim of treatment is to prolong survival and to improve quality of life. Patients with low-risk MDS mainly suffer from the effects of severe anemia and an important therapeutic goal is to maintain acceptable hemoglobin levels by optimal transfusion regimens or by erythropoietin ± granulocyte-colony-stimulating factor, which normalizes hemoglobin levels or abolish transfusion need in around 40% of patients. Lenalidomide has emerged as a drug of choice for patients with low-risk MDS and a 5q deletion, leading to complete erythroid response and cytogenetic remission in 2/3 of patients. A small cohort of younger patients may show excellent responses to anti-thymocyte globulin. Patients with more advanced disease may respond to treatment with the hypomethylating agents azacytidine and decitabine, who both have been shown to prolong time to leukemic transformation / death in MDS. In addition, there are several new agents under clinical investigation targeted to potential mechanisms of disease and progression in MDS. New therapeutic drug include inhibitors of angiogenesis, histone deacetylation, tyrosine kinases and farnesylation, as well as drugs interacting with apoptotic mechanisms. The role of these, alone and in combination with more established therapies will be discussed.