Bi-specific T-cell engagers

BiTE antibodies (Bite stands for "Bi-specific T-cell engagers") are artificial molecules engineered to contain binding sites for the T-cell receptor (TCR) and for tumor-associated or tumor-specific antigens in a single moiety.

BiTE antibodies consist of two scFv fragments linked by a peptide bridge.

One of the two scFv fragments exhibits selectivity for an antigen on a target cell. The other scFv fragment is able to bind specifically to surface proteins of T cells. In this way, BiTE antibodies can be used to direct a T-cell-mediated immune response against specific target cells, such as tumor cells. They are considered a new option in tumor therapy.

Blinatumomab is the first BiTE antibody used therapeutically. This bispecific antibody construct has dual specificity for CD19 and CD3 and belongs to the class of bispecific T cell engager antibodies that can potentially activate all of a patient's cytotoxic T cells for targeted lysis of tumor cells.

1. Locatelli F et al (2021) Effect of Blinatumomab vs Chemotherapy on Event-Free Survival Among Children With High-risk First-Relapse B-Cell Acute Lymphoblastic Leukemia: A Randomized Clinical Trial. JAMA 325: 843-854.
2. Nagorsen D et al (2012) linatumomab: a historical perspective. Pharmacol Ther 136:334-342.