Anti-CD19 strategies in hematological malignancies

Differentiation antigen CD19 (CD19) is a surface protein with an important role in both normal and malignant B-cell physiology. CD19 is an attractive target for novel immunotherapies in B-cell hematopoietic malignancies, as it is B cell-specific with few exceptions, widely and reliably expressed on malignant and normal B cells, and absent from pluripotent stem cells, as well as terminally differentiated plasma cells. A variety of approaches to anti-CD19 therapy have been explored, with several new techniques on the horizon. In this review, we discuss various methods of targeting CD19, including modified monoclonal antibodies, Fc-engineered antibodies, radioimmunotherapeutics, antibody-drug conjugates, bispecific agents and anti-CD19 chimeric antigen receptor (CAR) T cells.