Tumor is a new organism formed by abnormal proliferation of cells due to the loss of control of local cells' growth at the gene level under the action of various tumorigenic factors. According to the biological characteristics of tumors and their different degrees of harm to the body, they can be divided into benign and malignant tumors. In China, malignant tumor is one of the main causes of death of patients, and its incidence and mortality are rising, becoming a very serious public health problem.

Tumor therapy has always been a hot area of drug research and development, in which biological drugs play an important role. The biological targeted therapy of tumor is to design the corresponding therapeutic drugs (antibodies, CAR-T, etc.) at the cellular and molecular level, aiming at the identified targets, so as to play the role of inhibiting and killing tumor.

Compared with monotherapy or traditional combination therapy, the dual target properties of bispecific antibodies have key advantages in improving the antitumor efficacy: (1) simultaneously blocking two different targets or mediators that play a major role in the pathogenesis of the disease; (2) Induction of cellular signaling pathways (e.g., proliferation or inflammatory pathways); (3) Retargeting to regulate ADCC; (4) Avoiding the progression of drug resistance and improving the anti proliferative effect; (5) The patient's own cytotoxic T cells are temporarily combined with targeted cancer cells, thereby activating cytotoxic T cells to cause tumor lysis.