The Fab regions of rituximab binds to the CD20 antigen on B lymphocytes, while the Fc domain recruits antibodies and complements to mediate cell lysis.
Rituximab binds to the CD20 antigen, which is predominantly expressed on mature B cells and on >90% of B-cell non-Hodgkin's lympohomas. The antibody leads to selective killing of B-cells.
Most likely removed by opsonization via the reticuloendothelial system when bound to B lymphocytes, or by human antimurine antibody production