Scientists managed to create a vaccine against cancer

In two small studies, scientists demonstrated the effectiveness of an anti-cancer vaccine that helps patients fight the disease using their immune system that begins to attack cancer cells.

Experimental vaccine

In both studies, scientists used an experimental cancer vaccine to treat patients who developed a lethal form of melanoma (skin cancer). Both studies showed complete disappearance of the tumor in most patients after they were given an anticancer vaccine. For patients in the second group, another type of treatment was used, which provides an improvement in the ability of the immune system to fight cancer. In some patients of this group, the tumors also completely disappeared.

Now researchers are working on the development of similar vaccines against such types of cancer as glioblastoma (one type of brain cancer), cancer of kidneys, blood cells and ovaries. This is told by Dr. Catherine Wu, who is a scientist at the Dana-Farber Cancer Institute in Boston. She led one of the studies. "Many patients suffering from other cancers can benefit from vaccination," Wu said.

Activation of protective cells

Any cancer treatment should be aimed at cancer cells and spare healthy ones. In this approach, scientists want to get vaccines that can carry molecules that affect only cancer cells. Such vaccines can help the immune system "see" in cancer cells a threat, prompting it to attract protective cells (including T-lymphocytes) to get rid of cancer.

Use of abnormal proteins

For the control of melanoma, individual research groups worked with two different types of vaccines. The results of the tests they published on July 5 in the journal Nature.

Melanoma is often accompanied by mutations caused by exposure to the skin of ultraviolet rays. These mutations often lead to the appearance of abnormal proteins - neoantigens, which are no longer present in the human body. Doctors believe that they can be useful targets for the vaccine. This was stated by Dr. Cornelius Melif of Leiden University in the Netherlands, who did not participate in the research.

Features of the first study

In the first study, Wu and her colleagues vaccinated six patients who had previously undergone surgery to remove the tumor. The vaccine used was personalized by scientists for each individual patient: they performed DNA analysis of cancerous and healthy patient cells to find specific mutations of the tumor and associated neoantigens.

Then the scientists used computer modeling to predict which neoantigens immune cells can distinguish best. Then they injected the vaccine to the patients. Each vaccine contained up to 20 patient-specific neoantigens.

After the procedure, scientists were able to confirm the safety of the vaccine, as well as its ability to induce immune reactions in patients. Twenty-five months after the vaccination procedure, no signs of cancer were found in four patients. Two other patients suffering from a progressive form of melanoma later underwent a course of so-called control therapy, which blocks the mechanisms by which cancer can suppress the immune system. After further treatment, both patients showed complete regression of the tumor.

"We were pleased to see a consistent and strong response in six patients," Wu commented. "This proves that vaccines are able to mobilize a constant army of T-cells of the body."

How the second study was conducted

In another study conducted by Dr. Ugur Sahin from the University of Johannes Gutenberg in Mainz, Germany, scientists analyzed cancerous tumors in 13 patients and selected up to 10 mutations in each person to develop vaccines made from RNA molecules. These are the compounds that are responsible for coding the instructions used to form proteins such as neoantigens.

In the course of working with patients, scientists have discovered that vaccines can enhance their immune responses. 8 out of 13 could completely get rid of tumors after two years of treatment. The remaining five relapsed. However, one patient from the five had regression after taking control therapy.

Side effects

During the first study, the scientists noted the side effects caused by treatment. More often, they manifested themselves in the form of flu symptoms, fatigue and rash at the injection site. During the second study, there were no serious side effects.

The first phase of the test

Both studies are the first phase of clinical trials in which a small number of patients are involved. It is important to check the safety of the treatment. Also, the goal of scientists during the first phase is to find the best dose of the new drug with the least side effects. The results of such small-scale studies need to be confirmed for a large number of patients.

Although it is still too early to celebrate a complete victory over cancer, however, it seems that scientists are at the beginning of this path.