How can immunotherapy be used to work wonders? Experts take you to understand tumor immunotherapy

Text/Yangcheng Evening News All Media Reporter Zhang Hua

Figure/respondent provided

We all know that tumor has always been a difficult problem to overcome in medicine, and tumor drug treatment has also undergone three revolutions, from chemotherapy to targeted to today’s immunotherapy. Immunotherapy has brought tumor treatment into a new era of treatment. The patient’s survival has also been greatly improved. Chen Size, director of the Research Department of the First Affiliated Hospital of Guangdong Pharmaceutical University (Clinical School of Medicine) and professor of oncology, pointed out that with the wide application of PD1/PDL1 immune checkpoint inhibitors in clinical practice, we found that immunotherapy actually wants to achieve good efficacy. , Screening of dominant populations and combination with radiotherapy, chemotherapy, and targeted drugs are also very important.

The human body has three lines of immune defense

Generally speaking, what we think of as immunity is the body’s resistance to pathogens (germs, viruses) and harmful substances. In a broad sense, it is a special protective physiological function of biological organisms. Through immunity, biological organisms can recognize “self” and exclude “non-self”, that is, a series of processes such as the body’s recognition, elimination or elimination of foreign objects, in order to maintain the balance and stability of the internal environment.

So, how can we predict immune efficacy, and which patients will have better results with immunotherapy? This is not only an urgent need of patients, but also a hot spot of clinical research in recent years. Recently, Chen Size, director of the Scientific Research Department of the First Affiliated Hospital of Guangdong Pharmaceutical University (Clinical School of Medicine) and professor of oncology, said in an interview with reporters that the human body has three lines of immune defense to protect ourselves:

1. The skin and mucous membranes together constitute the first line of defense of the human body. For example, the mucous membranes of the respiratory tract can block and kill viruses or bacteria and avoid virus invasion;

2. The second line of defense is composed of non-specific immune cells such as phagocytes and body fluid bactericidal substances;

3. The third line of defense is to play a role through three immune organs and immune cells.

Immunotherapy requires genetic testing to select suitable patients

Many cancer patients benefit from immunotherapy, but not all cancer patients can benefit from it. Therefore, how to predict immune efficacy is not only an urgent need for patients, but also a research hotspot in recent years. Chen Sze pointed out that immunotherapy requires genetic testing to select suitable patients, and multiple immunotherapy predictors to determine whether it is suitable for immunotherapy.

Chen Size said, “It has been clinically found that high PD-L1 expression indicates more sensitivity to immunotherapy; MSI-H/dMMR patients are more sensitive to immunotherapy and can benefit from immunotherapy drugs. The greater the probability of benefit from immunotherapy; generally, the more TILs in tumor-infiltrating lymphocytes, the higher the efficacy of PD-1 inhibitors.”

What is the mechanism of tumor immunotherapy? Experts pointed out that, in simple terms, it is how to activate the immune system to recognize and remove tumor cells. Among them, the recognition of tumor cells by the immune system is a key link in tumor immunotherapy. In fact, it is a game of cat and mouse between the human immune system and tumor cells. At present, immune checkpoint inhibitors commonly used in tumor immunotherapy are mainly to release the inhibitory switch of tumor cells on immune cell killing, restore the normal activity and function of immune cells, and achieve the purpose of eliminating tumor cells.

Immunotherapy “combination boxing” to deal with advanced tumors is more effective

Compared with traditional chemotherapeutics and targeted drugs, once immunotherapy takes effect, the effect is durable, and the duration of remission can be doubled. Professor Chen Size said that for patients with advanced lung cancer after immunotherapy, statistics show that the five-year survival period can be increased from 5% to more than 30%. However, tumor treatment is actually a complex “engineering”, and it is difficult to achieve good results by relying solely on a certain treatment method. Therefore, at present, “combination punches” such as immunotherapy combined with targeted drugs and combined chemotherapy are implemented to deal with it. advanced tumor.

Taking lung cancer as an example, medical researchers in my country have used chemotherapy combined with immunotherapy to treat advanced non-small cell lung cancer. The study found that the disease control rate of chemotherapy combined with immunotherapy was 56%, which was significantly higher than that of chemotherapy alone, 37.5%. Survival was more than 1 year, and 47.6% of patients had no disease progression within 1 year.

Professor Chen Sze also gave an example, for example, CAR-T therapy is chimeric antigen receptor T cell immunotherapy, which is a new type of precise targeted therapy for the treatment of tumors. At present, the First Affiliated Hospital of Guangdong Pharmaceutical University has carried out CAR-T clinical trials for non-small cell lung cancer and esophageal cancer, as well as clinical studies of kaduclizumab (PD1/CTLA4 bispecific antibody) in the failure of single immunotherapy , If patients fail immunotherapy, they can also be considered for enrolling in these three clinical trials.

It is reported that the CAR-T clinical trial for non-small cell lung cancer currently being implemented in the hospital is the world’s first study of PD-1 knockout MUC-1 CAR-T in the treatment of advanced non-small cell lung cancer. Preliminary results show that PD-1 knockout MUC-1 CAR-T therapy is safe and tolerable, with some patients’ tumors shrinking significantly, and all enrolled patients’ symptoms improved.

In general, with the continuous advancement of medicine, the advent of immunotherapy has brought better survival benefits and improved quality of life for patients. (For more news, please pay attention to Yangcheng Pie

Source | Yangcheng Evening News Yangcheng School

Editor in charge | Liu Xinyu

Proofreading | Xie Zhizhong