Management of Multiple Myeloma and Myelodysplastic Syndrome: Focus on Lenalidomide

Lenalidomide belongs to a group of immunomodulatory drugs (IMiDs), fi rst known with the discovery of thalidomide in the 1950s, and which have then be tested in various malignancies for their clinical potential. It is described that these IMiDs exhibit multiple biologic effects on cytokine and cell-mediated responses. Lenalidomide was developed by chemical modifi cation of thalidomide to enhance the immunomodulatory potency but minimize the dose-limiting neu- rotoxic effects. This drug seems to have a positive clinical impact on hematologic malignancies including myelodysplastic syndrome, multiple myeloma, and chronic lymphocytic leukemia. Different potential mechanisms are discussed for lenalid- omide, including inhibition of angiogenesis, blockade of various cytokines and enhancement of immune system function. Even with strong improvement of the outcome of multiple myeloma, still most patients relapse and, therefore, drugs with new mechanisms of action are urgently needed to overcome this resistance. As for myelodysplastic syndromes, a heteroge- neous collection of hematopoietic disorders characterized by cytopenia, treatment options also have increased over the past 10 years, but still supportive care, cell-stimulating agents and chemotherapy with little impact on long-term outcome are offered to patients. In this review, we discuss the impact of lenalidomide on relapsed myeloma and transfusion dependent MDS as a novel strategy under assessment in preclinical and clinical trials. It was shown that Lenalidomide had clinical potential in both entities and its effectiveness might be enhanced by the rational combination with conventional agents.