Multiple myeloma, immunotherapy and minimal residual disease.

Multiple myeloma (MM) is an incurable heterogeneous hematological malignancy in which relapse is characterized by re-growth of residual tumor and immune suppression with a complex biology that affects many aspects of the disease and its response to treatment. The bone marrow microenvironment, including immune cells, plays a central role in MM pathogenesis, survival, and drug resistance. The advances in basic and translational research, introduction of novel agents, particularly combination therapies, improved indicators of quality of life and survival. Minimal residual disease (MRD) detection by multiparameter flow cytometry (MFC) has revolutionized monitoring of treatment response in MM. The importance of MFC methodology will be further strengthened by the ongoing international standardization efforts. Results of MRD testing provide unique and clinically important information and demonstrated the prognostic significance of MRD in patients, leading to regulate treatment intensity in many contemporary protocols. In this review, we will summarize the principal approaches in MM immunotherapy, focusing how new agents have potential in the treatment of MM and application of MRD detection by MFC as a surrogate endpoint would allow quicker evaluation of treatment outcomes and rapid identification of effective new therapies.