These bispecific molecules are created by linking the targeting regions of two antibodies. One arm of the molecule is engineered to bind with a protein found on the surface of cytotoxic T cells, and the other arm is designed to bind to a specific protein found primarily on tumor cells.
When both targets are engaged, the BiTE® molecule forms a bridge between the cytotoxic T cell and the tumor cell, which enables the T cell to recognize the tumor cell and fight it through an infusion of toxic molecules. The tumor-binding arm of the molecule can be altered to create different BiTE® molecules that target different types of cancer.
A BiTE® antibody construct is a type of fusion protein that is designed to harness the power of the immune system to treat cancer.
BiTE® molecules are deigned to form a bridge between cancer cells and cytotoxic T cells—white blood cells that can destroy other cells that pose a threat. One arm of the BiTE molecule binds to CD3, an antigen found on the surface of T cells. The other arm is engineered to bind to a tumor-associated antigen (TAA).1
When both arms of the BiTE® molecule are bound to their specific targets, a synapse forms between the T cell and the cancer cell. The T cells release perforin to form a pore in the wall of the cancer cells, and toxic molecules called granzymes flow through the pore, leading to the death of the cancer cell.
1. Baeuerle PA, Kufer P, Bargou R. Curr Opin Mol Ther. 2009;11:22-30.