Tumor bio-targeted therapy is tumor bio-targeted immune therapy. It selectively transfers drugs and active substances to kill cancer cells in the tumor. The treatment effect of drug targets the special cell, tissue and organ without affecting normal cells, tissue and organ to maximize curative effect and reduce side effects.
Targeted therapy refers to a therapy which aims at specific cancer cells. Molecular cancer therapy targets specific cancer cells or certain protein or a molecule of cancer cells. It can be divided into three types:
The first type targets a specified organ. For example, a specific drug is only effective for a particular organ. This is called organ targeted.
The second type is cell targeted, which refers to the drug selectively and specifically combine with a particular type of cancer cell after it enters the human body to cause apoptosis.
The third type is molecular targeted, which refers to a therapy aiming a certain molecular of a certain protein in cancer cells or a fragment of nucleotide or gene product to be treated. The target of bio-targeted therapy has these three aspects: cell growth factor receptor, intracellular signal transduction system and neo vessels.
The greatest advantage of bio-targeted therapy is, these drugs can focus on the special segment of the cancer metabolism and its targeting accuracy. Its effect is remarkable and it cannot harm normal tissues when it kills cancer cells. Therefore, bio-targeted therapy is considered the most promising therapy in the future of cancer treatment.
Currently targeted drug normally used can be divided into three types:
1.Small molecule drug (effective on intracellular signaling system)
Small molecule drugs usually transmit inhibitor via signals. Cancer growth and proliferation needs is signal transduction pathway which is specifically blocked by small molecule drug to achieve the goal of treatment. For example, Gleevec (known as Imitinib) is applied to treat chronic myelogenous leukemia and gastrointestinal stromal cancer; Sprycel (known as Dasatinib ) is applied to treat chronic myeloid leukemia which has a drug resistance; Iressa (known as Gefitinib) and Tarceva (known as Erlotinib) , taking EGFR as a target, it is to treat non-small cell lung cancer.
2.Monoclonal antibodies (effective on cell growth factor receptor)
For example, Herceptin (known as Trastuzumab) is to treat breast cancer of HER2 gene positive (overdose expression), Erbitux (known as Cetuximab), taking EGFR as a target, it is to treat colon cancer and non-small cell lung cancer and etc… These drugs can identify cancer cells via combining specificity of the antigen anti-body.
3.Anti-angiogenesis Drugs
There are bevacizumab and endostatin. Bevacizumab (avastin, rhuMab-VEGF) is VEGF ligand monoclonal anti-body. Endostatin is a kind of endogenous anti - angiogenic factor, separating from hemangioendothelioma.
With the exception of the above targeted drugs applied in clinical medicine, the other various targeted drugs have been developing.
