Immune modulatory agents in hematopoietic malignancies

Immune modulatory drugs have been successfully used to treat patients with multiple myeloma (MM), myelodysplastic syndromes displaying loss of 5q (del5q MDS) and chronic lymphocytic leukemia (CLL). Immune modulatory drugs are used in first-line therapy in combination with functionally complementary compounds, but have also shown efficacy in refractory disease. However, their exact mode of action remains unclear. Here we describe the clinical impact of these compounds on MM, del5q MDS and CLL, discuss their mode of action with respect to intracellular targets, focus on the phenotypic changes that immune modulatory compounds induce in the tumor microenvironment and how they modulate the immune response.