Filenews 20 January 2024 - by Marilena Panayi
At the forefront of international news is the huge scientific development that seems to promise a strong blow to the scourge of cancer.
The results of the studies, which of course are ongoing, and concern the development of personalized vaccines that seem to deliver critical blows to specific types of cancer, inevitably aroused the interest of the international community and the world is watching, with bated breath, the developments.
But what is this revolution that came and shook the waters? How do vaccines work? What do they promise and how much should we place our hopes in them?
Despite the fact that the development of these vaccines does not bring the end of the road in the battle against cancer, scientists appear optimistic, citizens are watching, drug manufacturers are in full activity. At the forefront are mRNA vaccines. The first potential "victims" of these vaccines are pancreatic cancer and melanoma (skin cancer).
Simply and popularly, the vaccines being developed target cancerous tumours and prevent their further growth.
The results so far are encouraging, with the use of mRNA technology, known from the recent pandemic and their success in dealing with the coronavirus. The data, of course, regarding the action and the way the new vaccines work are completely different.
In order to understand the technology that is currently evolving, it would perhaps be more appropriate to refer to the etymology of the word "vaccine".
Strictly speaking vaccine, it is called the "timeless loan" and this term clearly reflects the way preventive vaccines work that we all know and admittedly and proven to save the human species for decades from pathogens, which before the appearance of vaccines were literally reaping. In ancient Greek "embolo" (en-vallo). That is, I enter. In the case of therapeutic vaccines, it is the introduction of substances that drive the body itself, targeted to fight hostile cancer cells.
The scientific data that prevail at the moment, explains to "F" the associate professor of the University of Nicosia Christos Petrou.
"What was recently announced and aroused worldwide interest concerns the results of studies. Pharmaceutical companies Moderna and Merck presented promising results from a phase 2b clinical trial that investigated a combination of messenger RNA (mRNA) vaccine and an anticancer drug to treat melanoma.
The investigational melanoma vaccine, which uses the mRNA platform, in combination with the monoclonal antibody pembrolizumab, appears to reduce the risk of relapse. Mortality rates were reduced by 44% in this phase II clinical trial, which is already underway."
In the case of therapeutic vaccines, "it is obvious that there will not be one universal cancer vaccine, but rather several personalized ones. That is, a vaccine will not be manufactured and given to all patients who develop a particular type of cancer. Each vaccine, that is, each treatment, will be individualized."
How vaccines work
In the traditional sense, preventive vaccines prepare the human immune system so that the moment a pathogen (e.g. virus) enters the body, they can recognize, attack and neutralize it. In other words, the "perpetual loan" is activated at the moment of need.
But in the case of therapeutic vaccines, such as those currently being developed for cancer, things are somewhat different. These vaccines show the body the target to hit at that particular moment.
That is, "the vaccines that are now being developed lead to the identification of proteins present in specific cancer cells. For example, a virus has antigens on its surface that cause the immune system to attack it when the need arises. Cancer cells also have antigens on their surface." (To further understand how they work, we could turn the scientific term "antigens" into "targets." That is, the vaccines now being manufactured identify specific targets in cancer cells and hit them.)
"Tumor-related antigens are proteins found in cancer cells. Normal cells either don't have these antigens, or if they do, they have a much smaller amount. Vaccines to treat cancer help the immune system recognize these antigens found in cancer cells and lead to their destruction, so that targeting selectively targets cancer cells and does not affect normal and healthy cells."
This whole process, the mobilization of the internal defense mechanism that exists in each person, and leads to the "recognition" of the "enemy" is called "immunotherapy". It is the treatment that targets the patient's own immune system, stimulating it and releasing the special cells that attack and destroy cancerous tumours.
Obstacle: heterogeneity between cancer types
A big problem for the widespread treatment of cancer with immunotherapy, Petrou explained, "is the heterogeneity that prevails between different types of cancer or the mechanisms that tumours can develop to avoid treatment." Simply put, each type of cancer has its own different characteristics, which differ even from person to person. That is why "it is important to have personalized treatments that the new field of precision medicine offers. That is, through these new technologies that are being developed, it will be possible to take a sample from a tumour, perform a biopsy and create specific antibodies or mRNAs that lead to the production of specific antibodies by the same organism and effectively target cancer cells. Of course, if some types of tumours are the same, that is, they have the same characteristics and the same antigens on the surface of their cells, then there could be a class of mRNA vaccines given to a large group of patients with the same type of tumour."
Specifically for mRNA technology, "some technical problems in administration have now been solved and the technology can be applied, both in the treatment of cancer, but also in the future for other diseases."
Another disadvantage of the new technology is the fact that it works to "wake up" the immune system. "The problem is the aging of the immune system (elderly) or previous chemotherapy or radiotherapy that has suppressed the immune system."
Preventive cancer vaccines
Humanity in the last two decades has in its hands preventive vaccines against cancer and specifically against the human papillomavirus that causes cervical cancer. "Immunization against the human papillomavirus reduced cervical tumours caused by this disease by 87% among vaccinated people." At the same time, "vaccines against hepatitis B helped prevent liver cancer."
