AACR – 2016 Conference

Scientists believe that personalized vaccines will save the world from cancer

Evgenia Efimova, Vesti

Scientists today are having a lot of discussions about the development and use of anti-cancer vaccines, which are created individually for each patient, depending on mutations in specific tumors.

Preliminary clinical trials raise hopes that such a cancer treatment technique may one day become commonplace. But only if drug developers increase and accelerate the production of such drugs. This topic was the focus of attention at the annual conference of the American Association for Cancer Research (AACR), held in New Orleans.

The researchers spoke about the preliminary data of clinical trials. They suggest that a personalized vaccine can trigger an immune response aimed at destroying cancer cells. Investors are optimistic. They are ready to invest in such programs and believe that these results will be able to give benefits to patients.

However, some researchers are afraid of the hype around this topic and remind that it is still too early to apply this technology. Moreover, this method still faces a lot of technical problems.

The very concept of a vaccine to treat cancer is already a challenge. Some tumor proteins are either mutated, or they are produced more or less than in normal skin. As a result, the human immune system may mistake these "unusual" proteins for foreign ones. Especially if it is prepared for their presence with the help of a vaccine. Recall that it contains fragments of mutated protein and actually incites the immune system against them (which in itself is not terrible if it does not lead to the development of autoimmune diseases).

After the introduction of the vaccine into the tumor, the "army" of T cells of the immune system must seek out and destroy cancer cells carrying the target protein. But there is an important note: decades of research in the field of cancer vaccines still bring disappointing results from clinical trials. However, recent advances, including a series of drugs that can enhance the effect of the vaccine, revive the hopes of scientists.

Also, DNA sequencing of tumor cells showed that there is an incredible variety of mutations in the "broken" cells. They can serve as targets for immune system cells.

Last year, scientists reported that they were able to trigger an immune response in three patients with melanoma (skin cancer) using a vaccine. Such a vaccine was previously "incited" to their potential tumor antigens.

The effect of the vaccine on tumor growth has not been fully studied, but by the end of 2015, several companies announced their desire to invest in the development of such projects. At least three such companies are known – Gritstone Oncology, Therapeutics of Cambridge and Caperna.

Research groups are also keeping up with investors. Robert Schreiber from the University of Washington spoke at the conference about six studies of this problem that are currently underway at his institute. Another researcher in this field, Catherine Wu from the Dana-Farber Cancer Research Institute, also provided information about other trials related to the treatment of melanoma. They show the reaction of T cells to the vaccine.

But the work on creating a vaccine will take about 12 weeks for the Wu team, and about eight weeks for scientists from the University of Washington. This technique is expected to slow down the growth of tumors in patients.

It is noted that there are several reasons why many researchers choose melanoma for control and verification clinical trials. A skin tumor, as a rule, conceals many mutations (sometimes thousands of them). This gives scientists the opportunity to choose those that can serve as antigens. The same approach can be used in the future for other cancers with a large number of mutations – lung, colon and bladder.

Some scientists worry that the personalized vaccine method is not suitable for people with tumors with fewer mutations. Meanwhile, they also need help. In the case of active development of personalized cancer treatment methods, fewer scientific resources will be devoted to them (despite the fact that the effectiveness of the personalized approach has not been proven).

Schreiber tries to parry: recently, experts have managed to develop a vaccine for a woman with a brain tumor – glioblastoma, which often has relatively few mutations. However, it was in this case that there were many mutations (some of which could have been caused by previous courses of treatment of the patient).

In summary, many scientists are concerned that the personalized approach leaves behind decades of research on antigens that may be common to all tumors. Such a "mass" approach has not yet been confirmed in clinical trials, but it would be much easier to create a cure for any type of cancer, and it would be cheaper for patients, since it can be produced on a large scale.

Portal "Eternal youth" http://vechnayamolodost.ru  27.04.2016