Multiple myeloma (MM) has been mostly incurable due to its highly complex and 
heterogeneous molecular abnormalities and the support from myeloma 
microenvironment factors. A therapeutic strategy which effectively targets 
relevant and specific molecule to myeloma cells, and which is potent in 
overcoming tumor microenvironment-mediated drug resistance needs to be 
developed. One of the promising fields is the development of immunotherapy using 
monoclonal antibodies (MoAbs) against myeloma-specific antigens. This review 
focuses on the basic and clinical aspects of two emerging and promising novel 
MoAbs for MM, elotuzumab which targets CS1 and daratumumab which targets CD38. 
Both antigens are relatively specific to myeloma cells and expressed in more 
than 90% of MM patients, and mediate adhesion of myeloma cells to bone marrow 
stromal cells. We also discuss the unique characteristics of the two MoAbs by 
comparing with other MoAbs being developed for MM.