The subject invention provides novel methods for treating B cell malignancies, such as multiple myeloma, using a combination therapy. Said treatment in accordance with the subject invention comprises the administration of a B cell regulator, e.g., a galectin molecule, to a subject suffering from a B cell malignancy, and wherein said subject received, receives, or will receive a treatment with a conventional treatment for such B cell malignancy, e.g., immunotherapy. The administration of the galectin molecule boosts the expression of B cell specific antigens e.g., SLAMF7, on MM cells, thereby increasing the sensitivity of MM cells to anti-SLAMF7 Ab and therapeutic efficacy of Elotuzumab.