Most of the antibodies currently used in therapy are monospecific or monoclonal – they specifically target a particular part of an antigen, called an epitope. The heterogeneous nature of the cancer allows frequent mutations and cross-talk among multiple signaling cascades, which ultimately leads to uncontrollable growth and proliferation of the tumor. Thus, antibodies that bind to two different epitopes on the same or different antigens (known as bispecific) are conceptually superior to monoclonal antibodies. The “dual-target” functionality of the bi-specific antibody consisting of two variable domains allows it to bind to multiple surface receptors or ligands in signaling pathways. Although this phenomenon was identified 30 years back, the first bispecific antibody [Removab – catamuxumab: binds to epithelial cell adhesion molecule (EpCAM) on tumor cells the CD3 antigen on T-cells] was approved for therapy in 2009 in Europe for the treatment of malignant ascites after long years of research and development. Continue reading →