Cancer treatment: from early diagnosis to gene therapy and preventive vaccine

Gene attack on cancer
Vladislav Novikov, STRF.ru

The Institute of Gene Biology of the Russian Academy of Sciences (IBG RAS) has created the production of test kits for cancer genodiagnostics designed to detect oncological diseases at the earliest stages and rationalize the choice of their treatment strategy. At the stage of obtaining permission to conduct clinical trials, there is a cancer vaccine, which will be a fundamentally new word in the prevention and treatment of oncological diseases.

There are two types of immunity in humans: innate and acquired. Innate immunity is responsible for the overall resistance of the body, is the first line of defense against pathogens. Acquired immunity is formed as a result of diseases or vaccination, it fights infections and is involved in the neutralization and removal from the body of foreign molecules that have previously entered the body. The system of innate immunity is evolutionarily more ancient, it has a greater potential compared to acquired immunity. It was the activation of the innate immune system that researchers from the IBG RAS used to fight cancer.

"A number of genes related to the formation and functioning of tumor cells in the body have been discovered at our institute," says Sergey Larin, head of the Laboratory of Gene Therapy at IBG RAS. "Scientists have found a correlation between the expression of these genes and the formation of tumor cells in the patient's body. The involvement of one of these genes in the regulation of the innate immune response was revealed. This was the starting point in the creation of a vaccine against cancer."

Active work in the field of stimulation of antitumor immunity for therapeutic purposes began at the IBG RAS in the mid-90s of the last century. In addition to the IBG RAS, the N. N. Petrov Research Institute of Oncology in St. Petersburg, the N. N. Blokhin Russian Cancer Research Center (RONC RAMS) in Moscow and other institutions participated in the work.

"Danger flag" on tumor cellsAt the beginning of the work, the molecular mechanisms of innate immunity were not known.

In 1996, Olga Kustikova, an employee of the IBG RAS, discovered the Tag7 gene. The protein encoded by this gene turned out to be an inducer of innate immunity. Work has begun to study its protective role in mice. The gene was injected into mouse tumor cells and then these tumor cells were injected into mice. It turned out that such genetically modified tumor cells did not cause the formation of tumors in mice, that is, the introduction of one gene changed the dynamics of tumor development. This confirmed the hypothesis that the proposed approach can be used for antitumor immunostimulation.

Later it turned out that if, after the introduction of modified tumor cells, mice were also injected with the original unmodified tumor cells, which usually kill the mouse, then such mice are protected. So specialists learned to put a "danger flag" on tumor cells, as a result of which the immune system began to recognize the tumor, and lymphocytes were able to distinguish tumor cells that had previously been "invisible".

The introduction of modified cells into the body adjusts the innate immunity so that with the development of an already unmodified tumor, the mechanism of the acquired immune response is triggered.

From experiments on mice to clinical trials of the vaccineThe first experiments on mice were started in the mid-90s, and the first clinical trials took place in 2000.

An ex vivo gene therapy scheme was used. Tumor cells were taken from the patient and genetic constructs encoding therapeutic genes were injected into them, which led to the expression of a therapeutic protein, and the tumor cells themselves were inactivated (blocked their reproduction) by irradiation. In the future, having done all the necessary tests to assess the quality and safety of such genetically modified cells, they were injected back into the patient in order to stimulate his own antitumor immunity. In fact, it was an individual vaccine. But this path turned out to be very difficult technically, long and expensive. And most importantly, this type of treatment could only help a limited number of patients.

In the course of this work, scientists managed to create a bank of tumor cells of patients. The composition of antigens was determined for each tumor. Then several universal cell lines were selected from this bank, which contain a wide range of known tumor antigens.

But it is important to note here that each tumor in patients occurs as a result of individual genetic breakdowns. Each oncological disease is individual according to the set of molecular changes that have occurred in each cell. This is one of the main reasons why not a single drug has yet been created that would allow killing absolutely all tumor cells.

Having accumulated such a bank and selected universal groups of cells from it, the researchers were able to create a universal vaccine that would not be suitable for everyone, but for a sufficiently large number of patients.

The main conclusion that scientists made based on the results of clinical trials conducted with a prototype of the vaccine currently being developed in the early 2000s: it is necessary to carefully monitor the selection of patients and the choice of individual treatment regimens for them. In laboratory conditions, the staff of the IBG RAS made a number of developments that made it possible to get as close as possible to the molecular certification of both vaccine cells and patient tumors. This made it possible to exclude potentially unresponsive patients from the trials.

In addition, in parallel, work has begun on the creation of tests that allow a meaningful and rationalistic approach to the choice of a further strategy for the treatment of such patients.

Genodiagnostics in the service of oncologistsTo date, the main ideology of the treatment of malignant tumors is the use of surgical, chemotherapeutic or radiotherapy techniques.

In the case of chemotherapy, traditional regimens are usually prescribed – therapy of the first, second, and third lines. If the patient was helped by first–line therapy, it means luck, and improvement, remission or complete recovery occurs. If the first-line therapy did not help, the next, often more toxic combination of drugs is prescribed. The second one did not bring results either – they are transferred to the third line. In order to understand the results of each therapy regimen, it takes time – from one to three months. Only after this period it is possible to draw conclusions about how effective this scheme is in a particular patient. Sometimes you have to wait up to six months for the effect.

One of the main causes of high mortality from cancer in Russia is the destruction of the medical examination system that existed in Soviet times.

Currently, in Russia, patients who go to the doctor about malignant tumors come, as a rule, at rather late stages, with an already common form of the tumor. Very often this is the third, fourth stage, when the process of metastasis has already affected the lymph nodes and vital organs. In such patients, the time to choose a line of therapy is significantly limited and there are actually a limited number of attempts to change the therapy regimen. The results of recent scientific studies allow us to use the relationship of genetic mutations in specific cancer cells with the effectiveness of currently existing treatment regimens.

In order for a normal cell to be reborn into a tumor cell, several independent mutations must occur in different parts of the genome. Such mutations allow tumor cells to adapt to different survival conditions, often quite harsh. While a normal cell would die in such conditions, a tumor cell is less demanding of oxygen content, nutritional growth factors, it is more resistant to various external influences. The accumulation of mutations leads to the fact that cancer cells turn into less dependent on surrounding cells, they become stronger and "angrier" than normal cells. At the moment when five or six mutations occur in a cell, the "machine" of intracellular division control breaks down. New mutations accumulate in the cells and, in medical terms, tumor progression begins. A set of mutations of a specific tumor cell is often called a "molecular portrait" of a tumor.

During chemotherapeutic exposure or radiation, most of the tumor cells die, but progressive mutations lead to the fact that the remaining part of cancer cells adapts and becomes insensitive to these influences. Here we have to apply an integrated approach: surgery, chemotherapy, radiotherapy and immunotherapy. For a number of tumors, none of these types of treatment individually gives one hundred percent effect.

"Today, a certain group of drugs is used to treat each type of cancer – for the treatment of lung cancer, breast cancer or glioblastoma (brain tumors – STRF.ru ), – Sergey Larin explains. – However, doctors all over the world are beginning to approach this more rationally: the sensitivity of a tumor to therapy is determined not by what cells it originated from, but by what mutations are accumulated in it, that is, the molecular portrait of a cancer cell. And it may turn out that a lung tumor should be treated with a breast cancer drug, and glioblastoma with the drugs that treated the lung tumor. Treatment is determined based on the molecular profile of tumor cells."

This approach avoids obviously ineffective treatment of the patient and saves public money. According to American researchers, the introduction of a number of molecular genetic tests saves on average from 20 to 100 thousand US dollars per patient per year. And the most important thing is that, in addition to saving budget funds, the quality of treatment increases. According to statistics, most of the patients whose choice of therapy was made taking into account the preliminary analysis of individual genetic characteristics respond better to the recommended drugs. In the USA, such an approach to the treatment of oncological diseases is actively developing now, but in our country it is still in its infancy.

From the state – 155 millionAgainst the background of the successes of fundamental science, there have been changes in the current legislation, which have significantly complicated the further introduction of original innovative drugs of Russian development.

After successful animal trials, the vaccine was supposed to undergo clinical trials, but recently the requirements for their conduct have become seriously tightened. Since September 1, 2010, clinical trials can only be carried out with industrial samples of the vaccine. It is very difficult to find sponsors of clinical trials among private pharmaceutical companies. Even the launch of experimental production requires enormous investments, and the cost of industrial production is even higher by an order of magnitude. If the tests fail and it turns out that this industrial line is not needed by anyone, it turns out that the pharmaceutical manufacturer has wasted money.

And then the state came to the rescue, which financed most of the research related to the development and development of industrial technology. In 2008, the Ministry of Education and Science initiated the implementation of the project "Development of technologies for genodiagnostics and gene therapy of cancer and the production of prototypes of test kits and gene-cell antitumor vaccines within the Federal Target Program "Research and Development in priority areas of development of the scientific and technological complex of Russia for 2007-2012" for a period of 2.5 years in the amount of 155 million rubles.

In addition to IBG RAS, an extensive network of co-executors participates in the work on the implementation of this state contract. These are the N. N. Petrov Research Institute of Oncology, the Federal Research and Clinical Center for Pediatric Hematology, Oncology and Immunology, a number of medical institutions in Siberia, the Nizhny Novgorod State Medical Academy, Binnopharm CJSC (Zelenograd) and a number of other scientific and commercial organizations.

Initially, the fundamental developments of scientists were primarily aimed at creating cancer immunotherapy technologies, but today the development of modern methods of gene diagnostics has been added to the main tasks. It is the early and timely detection of the disease that should change the existing statistics.

To date, the percentage of oncological diseases in Russia is not much higher than the statistics of most developed countries.

A small preponderance in our country is associated with the spread of smoking and alcoholism. At the same time, in the West, the disease is most often diagnosed at early stages, in our country – at late stages, which significantly reduces the chance of recovery.

"The main task that the state sets for us is to get a practically significant result and a drug," comments Sergey Larin. – Despite the fact that we are an academic institute, academic research ended at the stage of working with mice. That was five years ago. We have published a number of papers in the world's leading scientific journals. Now our task is to make a real, tangible product. To date, we have created several products. Registration documents of the Federal Service for Supervision of Healthcare and Social Development have already been received for some of them, and positive decisions on the issuance of such documents have been made for some of them."

The developed diagnostic test kits are designed to determine the predisposition and risk group for the development of oncological diseases. They allow you to choose and prescribe therapy for patients in a timely manner. There is already a practice of detecting malignant cells by molecular methods in the early stages, when tumor nodes were not detected by traditional methods (X-ray and tomography). Before the tumor metastasized, it is well treated surgically and there are more options in chemotherapy. Molecular genetic methods are highly sensitive: they allow you to identify single cells in 10-100 milliliters of blood.

Roszdravnadzor registration certificates have already been received for diagnostic kits developed by IBG RAS, and they will go on sale in the near future.

A production facility has been established on the basis of the institute, which has produced experimental batches of developed kits that represent a high-tech product for specific specialists. Since the volume of demand in our country is known, the existing production can well provide all specialized laboratories.

The ownership rights to the developments belong to the Russian Federation represented by the Ministry of Education and Science and the contractor of the contract – IBG RAS. All technological work on the creation of the vaccine, including the creation of production, was carried out on the basis of Binnopharm CJSC, one of the largest manufacturers of full–cycle biopharm substances in the Russian Federation.

Vaccine: not only treatment, but also preventionThe vaccine developed by IBG RAS will undergo clinical trials as a therapeutic agent.

This vaccine is not yet used in the usual preventive use scheme – we are talking about therapy. In the future, for a number of patients who will have an increased tendency to develop cancer, this vaccine can be used for preventive purposes. There is a group of so–called precancerous diseases - changes that are highly likely to transform into cancer. In the future, for such patients, this drug will be used in the classical vaccination scheme. Trials on preventive schemes will be initiated after receiving the results of therapeutic schemes.

Initially, the vaccine was conceived as a highly specific drug for melanoma (skin cancer). But within the framework of the state contract with the Ministry of Education and Science, results were obtained that significantly expanded the potential areas of its application for other forms of the disease.

It is ineffective to apply immunogenotherapy, which uses genetically modified tumor cells, in the case of late stages of oncological diseases with a widespread tumor process. The immune system is good at fighting metastases, with single tumor cells. "In the future, we hope to work in tandem with surgeons," says Sergey Larin. – They will remove the main tumor mass, and micrometastases scattered throughout the body, which surgeons cannot cope with, are a target for vaccine therapy. The main difficulty in fighting cancer is not to remove 90 percent of tumor cells or 99 percent. The problem is to remove 100 percent of tumor cells from the body. We hope that complex therapy, including immunostimulation, will allow us to do this."

Unlike traditional methods of cancer treatment, immunotherapy is quite harmless and harmless. The complications that occur are traditional for many vaccines: fever, a flu-like condition that can persist for one or two days.

Rusnano will help bring the vaccine to the marketThe contract of the Ministry of Education and Science was aimed at creating technologies for introducing the results of fundamental research into production.

The project funded the preclinical stage of trials, but the most expensive thing to date is to create an industrial production and conduct clinical trials.

"In the case of diagnostic reagent kits, clinical trials are not required," explains Sergey Larin. – We have conducted technical and medical tests, the results of which are quite predictable. Therefore, we managed to do a little more than was required under the state contract: our task was to develop a package of scientific and technical documentation, and we managed to get a registration certificate."

Production of the vaccine is currently ready to launch. The issue of further implementation of these works and financing of clinical trials of the vaccine is currently being discussed with Rusnano Group of Companies. In August 2010, the Scientific Coordination Council of Rusnano approved the project. The state Corporation plans to open financing for the development and production of a number of innovative drugs that will be produced by Binnopharm CJSC, and this vaccine is one of them.

In case of successful clinical trials, it is planned to conclude a license agreement between Rusnano Group of Companies, Binnopharm CJSC and IBG RAS, according to which the institute will receive royalties. It is expected that about three and a half to four years will pass from the start of financing of the Rusnano project before the vaccine enters the market.

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31.01.2011