New targeted drug for colorectal cancer in the United States

Tumor molecular targeted therapy drugs refer to drugs developed for the special biological characteristics of tumor cells, which can specifically inhibit tumor growth and metastasis. Targeted therapy is a new tumor treatment method after surgery, radiotherapy, and chemotherapy. It is highly targeted and molecularly specific, and has the advantages of high efficiency and low toxicity. It is a new weapon and new hope for tumor treatment. At present, there are two main targeted drugs approved by the State Food and Drug Administration for marketing in China: bevacizumab and cetuximab. These two drugs also represent two types of anti-tumor molecular targeted drugs, namely anti-peripheral vascular growth factor and anti-epidermal growth factor.

Bevacizumab belongs to the class of anti-tumor angiogenesis drugs. It is a humanized monoclonal antibody against vascular endothelial growth factor. It does not act directly on tumor cells, but neutralizes the main molecule that causes tumor angiogenesis in the body - vascular endothelial growth factor (VEGF). Tumor cells grow rapidly. It is generally believed that when the tumor grows to 2-3mm3, new blood vessels must grow in to maintain the nutritional needs required for tumor growth. When the action of vascular endothelial growth factor is blocked, tumor angiogenesis is impaired, and tumor death and regression will occur. In addition, bevacizumab can also reduce the pressure between tissues, which is more conducive to the entry of chemotherapy drugs into tumor tissues to exert their effects. Therefore, bevacizumab is often used in combination with chemotherapy in clinical practice.
Cetuximab is a monoclonal antibody against epidermal growth factor receptor (EGFR), which can block the binding of EGFR to the receptor, thereby inhibiting the growth of tumor cells. In addition, after binding to tumor cells, it can also assist immune cells in the body to capture and kill tumor cells, which is the so-called "antibody-dependent cell-mediated cytotoxicity".