CD19 monoclonal antibodies work by targeting the CD19 protein that is present on the surface of pre-B and mature B lymphocytes and overexpressed in several different cancers, including CD19-positive B-cell leukemias or lymphomas.
  CD19 monoclonal antibodies may have slightly different ways of working. Some are considered bispecific T-cell engagers, and work by directing T-cells (an important part of our immune system) to target and bind with the CD19 protein that is present on CD19-positive B-cell leukemia or lymphoma cells. Others bind directly to the CD19 antigen and mediate the disintegration and rupture of the B-cell (also called B-cell lysis).