What does targeted therapy bring to the table?

Chemotherapy has been one of the main modalities of oncology treatment for decades. However, the toxicity that chemotherapy causes to patients makes them very fearful of chemotherapy. In essence, chemotherapy not only kills tumor cells, but also causes severe damage to many healthy cells, especially bone marrow hematopoietic cells, and is quite toxic to vital organs such as liver, kidneys, and heart, reducing the quality of patient’s survival to some extent. In order to overcome these toxicities, searching for specific substances related to tumor growth in the body and targeting them for specific inhibition to control tumor growth is the basic principle of molecularly targeted drugs. After years of research, there are now major breakthroughs in molecularly targeted therapies. To specifically target tumors, we need to find the “uniqueness” of tumors, that is, the difference between normal cells and tumor cells, in order to destroy tumor cells without affecting normal cells. At present, scientists have developed molecular targeting drugs against tumor cells and anti-angiogenesis, and some drugs have both characteristics, which are so-called multi-target drugs, not only anti-angiogenesis, but also against tumor cells. Now we know that there are more than 300 genes associated with the development of tumors. According to statistics, there are more than 100 targeted drugs on the market and under investigation. The first influential one is Imatinib (Gleevec), used to treat gastrointestinal mesenchymal tumors (a malignant tumor originating from the mesenchyme of the digestive tract). Gefitinib is highly effective against non-small cell lung cancer with EGFR mutations. Others are monoclonal antibodies, which have also been very effective in combination with chemotherapeutic agents. It is particularly exciting that for patients with a single mutation, a single drug can control the tumor very well. Recently, Pfizer developed Crizutinib, which treats ALK-positive non-small cell lung cancer with an efficacy of nearly 90%. This gives tremendous confidence to the majority of physicians. Now, we can say that we have really entered a new anti-tumor era, where we can control the development of tumor by suppressing one tumor gene, just like diabetes and hypertension, and turn tumor into a chronic disease that can be controlled. In the development of molecular targeted therapeutic drugs, China started late, but developed fast. We have achieved a jump in development. At present, there are nearly 20 kinds of drugs under development in China, accounting for about 1/10 of the world, and the development momentum is promising. It is believed that new anti-cancer targeted drugs developed in China will be available in the near future for the benefit of Chinese cancer patients. Since the first molecular targeted drugs were introduced, molecular targeted drugs have been involved in the treatment of almost all kinds of tumors in just a decade. Although the efficacy of some drugs is still not satisfactory, it can be expected that the next decade will be a period of rapid development of molecular targeted drugs. We eagerly expect that tumor control is no longer a fantasy!