Immunotherapy for malignant neoplasms

We are used to fighting cancer with radiation therapy, a surgeon's knife, antitumor antibiotics that affect all rapidly dividing cells, including blood-forming organs. Doctors in the treatment of Jimmy Carter used a different method. They prescribed him a drug called pembrolizumab. The drug acts on the patient's body using the principle of immunotherapy. A few months after starting the medication, all metastases disappeared.

1. Tumors are coming
2. The search for a cure is in full swing
3. At the intersection of immunology and Oncology
4. About difficulties and prospects

Jimmy Carter

Jimmy Carter, the 39th President of the United States, turned 94 in 2018. In 2015, he had a malignant liver tumor removed. After the operation, oncologists reported that the patient's condition did not improve. The tumor has metastasized. But Jimmy Carter was cured.

Tumors are coming

Malignant neoplasms are among the top five causes of death. According to statistics from the world health organization, 25% of people face cancer during their lives.

Previously, medicine tried to defeat epidemics, to cope with tuberculosis, etc. Only after a person began to live up to 70 years, the problem of cardiovascular diseases, malignant pathologies worsened. But cancer is not a sentence. Soon the patient, who will be informed about the detection of his tumor, will take the diagnosis calmly. The disease can be cured. Progress in this direction is already today.

Over the past 20 years, the mortality rate from cancer has decreased by 20%. This is due to the improvement of surgical methods, the use of operating robots, the development of means of delivering radiation directly to the tumor. Progress has occurred due to radiation therapy: gamma and Cyberoam. But these methods work if the cancer has not had time to multiply in the body, there are no regional, distant metastases. However, often the initial treatment of the patient to the doctor is put already 3, 4 stage of the disease. The way out is to look for a cure for cancer, to apply new mechanisms of action.

The search for a cure is in full swing

Cancer drugs are being intensively sought in developed countries. Oncology is a topic discussed by many pharmaceutical manufacturers. In the field of immunomodulatory therapy, the facts necessary for the production of drugs are found almost every day.

This direction in Oncology differs from other methods of systemic approach that allows you to act on cancer cells throughout the body, regardless of location, stage of the disease. Other methods of treatment, except chemotherapy, affect the tumor locally.

From the point of view of philosophy, the chemotherapeutic method is a way of attacking malignant cells, in which healthy tissues are inevitably affected. After the courses, the use of anti-cancer antibiotics, patients feel bad, go bald, they have reduced the number of white blood cells, platelets in the blood, there are other complications. It is not only through attack that cancer cells can be destroyed. An effective way is to mobilize all means of suppressing tumor growth from within. This is the philosophical meaning of cancer immunoprophylaxis. The approach has been actively developing over the past 20 years.

The definition of immunotherapy was introduced in the mid-80s of the XX century by the outstanding oncologist from the USA Steve Rosenberg. Soon the first immunostimulator against cancer appeared, which was called alemtuzumab. It acted on the lymphocytic antigen CD52. The drug underwent long-term clinical trials, entered the international market in 2001. It is used in oncohematological pathologies.

There are about ten similar drugs, new drugs appear on average every 3 years. In 2014, I resigned pembrolizumab and nivolumab, in 2016 — tatlisumak.

At the intersection of immunology and Oncology

In the body of a healthy person, the immune system fights cancer cells, which sensitively reacts to their appearance, attacks before reproduction, consolidation in the tissue, organ. This is the basis of antitumor protection. It often happens that the immune system recognizes a malignant cell with great difficulty or can not do it at all. Immuno-oncological agents-drugs that enhance the ability of the immune system to fight the tumor.

The immune system protects against microorganisms, viruses. Own abnormal cells are destroyed in the normal mode. At the same time, living, healthy tissues are not damaged. Defense mechanisms that allow you to stop the already running immune response, prevent damage to normal cells.

To avoid destruction, malignant tumors use this stop. Cancer cells pretend to be healthy. The mechanism of blocking tumor suppression is triggered. One way to prevent this process is to administer a drug that removes the block. As a result, the body can destroy the tumor.

The work of immunity against cancer cells is not much different from killing accidentally caught in the blood of microbes. The scout cell detects it by specific antigenic markers located on the membrane. The obtained information is delivered to the peripheral organs of immunity, i.e. regional lymph nodes. There is a command that receives, processes the signal, directs T-lymphocytes to destroy the enemy with antibodies, phagocytosis, etc.in T-lymphocytes there is a special membrane protein PD-1, or a molecule of programmed death. When this compound is activated, the T-lymphocyte dies. In normalcy-after carry quests. However, tumor cells are able to start the process ahead of time.

The creation of cell vaccines for cancer immunotherapy for a specific patient involves a number of stages
In the foreground are studies, experiments to prevent programmed death of immune cells, the use of tumor (melanoma, glioma, etc.) cunning tactical weapons.

About difficulties and prospects

The principles of immunoprophylaxis are clear, in practice everything is a little different. There are dozens of studies related to the third phase of the drug.

There are cases where monoclonal antibodies do not work. This is due to the presence in the body of several varieties of tumor tissue markers.

A cancer called lung cancer is a malignant, aggressive tumor. Within the first 5 years after the detection of the disease, 85% of patients die. If a patient is diagnosed with stage 4, there is only one chance in 50 that he will live another 5 years. There are several varieties of this cancer. In one of them, tumor cells have the biomarker PD-L1. Such patients are about 25% of the total number of patients. It was for them that pembrolizumab proved effective. The rest of the drug does not help. But for some, life expectancy increases, the term of persistent remission is extended by 1 year.

Another promising area is immunoprophylaxis, i.e. the introduction of a recombinant vaccine (serum) based on tumor antigens into the organism. This prevents cervical cancer caused by human papilloma virus (HPV).

Immunotherapy uses not only monoclonal antibodies, but also dendritic cells. They are taken from the patient using extracorporeal methods, incubated with cancer antigen. The dendritic cells are then injected back into the patient. As a result, the immune system is activated, a lymphocytic response is formed.

Another method is the introduction of destroyed, lysed tumor tissue into the body. As a result, an immune response is also triggered.

Immunotherapy is the gateway to the future, which can be opened with the help of science, technological progress, equipped laboratories and trained personnel.