Contents
Scientists are working on vaccines to treat cancer. In the summer it was reported that one of the preparations would be tested in humans. In late January, the results of a four-year study of a personalized vaccine against melanoma, the most malignant skin cancer, were revealed. They show that it could hold back its development for years. There is, however, a “but”.
- Unlike vaccines to prevent infection, cancer vaccines do not prevent cancer, but remove already existing cancer cells.
- Melanoma-related cancer vaccine studies have shown that it induces a sustained immune response and may help control cancer, especially when combined with other immunotherapies
- The researchers point out that the study only included eight patients, and more research is needed to determine exactly how effective the vaccine is.
- More current information can be found on the Onet homepage.
How do cancer vaccines work?
In the summer of 2020, the “Clinical & Translational Immunology” magazine announced the planned launch of human trials to test the vaccine’s effectiveness against various types of cancer. – We hope that this vaccine will be used to treat blood cancers, such as myeloid leukemia, non-Hodgkin’s lymphoma, multiple myeloma, childhood leukemias, as well as solid tumors, including breast, lung, kidney, ovary, pancreatic and glioblastoma, she said leading the work of prof. Kristen Radford from the Translational Research Institute and the University of Queensland in Australia.
- The cancer vaccine is getting closer. Human tests are underway
On January 21, the journal Nature Medicine wrote about the effects of several years of research on a personalized vaccine against melanoma.
Unlike vaccines to prevent infection, cancer vaccines are a form of immunotherapy. Their task is not to prevent cancer, but to remove already existing cancer cells. Such preparations, in a way, “train” immune cells (T lymphocytes, ie white blood cells capable of recognizing antigens and identifying changed cells) in the best possible diagnosis of cancer and elimination of neoplastic cells, while sparing the healthy ones.
- How does the immune system work?
This is how the new experimental melanoma vaccine works. The product trains T lymphocytes to detect specific proteins on melanoma cells. In testing, researchers found that T cells “remember” these proteins for at least four years after vaccination. What’s more, over time they learn to recognize more proteins associated with this type of cancer.
All of this is possible when the cancer cells are killed. “Vaccine-induced T cells are likely to cause this killing,” said study author Dr. Catherine Wu of the Dana-Farber Cancer Institute and Harvard Medical School in Boston and the Broad Institute in Cambridge, Massachusetts. – Once killed, cancer cells decay, “spilling” their contents. T lymphocytes study these remains, recording information for possible future attacks, the doctor explains.
Research results: “durability of the immune response is striking”
What was the study published on January 21 in Nature Medicine? The experiment involved eight patients with advanced form of melanoma who recently underwent surgery for it. Tumors removed during surgery were sampled from patients and used to create personalized vaccines for each participant.
- Lymphocytes – the role in the body and deviations from the norm [EXPLAINED]
By studying the RNA of a given tumor, scientists were able to predict exactly which proteins (so-called neoantigens) would be ‘used’ in it. These tumor antigens are like a red flag for the immune system. The final vaccines therefore contained fragments of these neoantigens, so that the immune cells of the patients could “read” them and, in effect, “track” the cancer.
About four months after surgery to remove the tumors, participants received a personalized anti-cancer vaccine. Blood samples were taken from volunteers four years after administration of the preparation to test the T-cell response. Data on possible side effects were also collected (patients experienced only mild symptoms such as fatigue and flu-like symptoms).
- Genomic profiling as a chance to defeat cancer
“What is really striking is the durability of the immune response,” notes one of the study authors, oncologist Dr. Patrick Ott. Moreover, the immune response has changed over time, which means that T cells have learned to recognize neoantigens that were not present in the original vaccines.
Nobody expected vaccines to eliminate cancer on their own
At the end of the four-year follow-up period, all study participants were alive, and six of the eight volunteers had no symptoms of active cancer. Some experienced the cancer recurring earlier during the study period, receiving additional treatment.
“We thought from the outset that vaccines were a very important complementary therapy that could be used in conjunction with other potent agents,” said Dr. Catherine Wu. In other words, no one expected vaccines to completely eradicate cancer in patients on their own. And because several patients received treatment during the study, the team was able to see if the vaccine strengthened or weakened the other treatments.
In this regard, two patients were distinguished in whom the cancer had spread to the lungs and who therefore received additional treatment. They were treated with drugs that help to increase the activity of T lymphocytes. Thanks to the vaccine and the administered drugs, the detectable cancer was quickly eliminated in both patients.
‘It’s quite remarkable to see a complete immune response just after the initial treatment period, which was the case for both patients,’ said Dr Ott. – This is an early signal that the vaccine works with drugs and strengthens their effects.
More research is needed into the melanoma vaccine
Researchers involved in the study admit that the results are promising, and the data so far show that the vaccine elicits a sustained immune response and may help control melanoma, especially when combined with other immunotherapies. On the other hand, the researchers point out that the study only included eight patients, and more research is needed to determine exactly how effective the vaccine is.
“For this small number of patients, it is difficult to draw meaningful conclusions,” said Dr. Joshua Brody, director of the lymphoma immunotherapy program at the Icahn School of Medicine in Mount Sinai, New York (he did not participate in the study). ‘But we logically’ imagine ‘that vaccines enhance the effects of drugs administered to cancer patients, and that these findings should’ withstand ‘larger clinical trials, says the scientist.
Dr. Paweł Kaliński, director of cancer vaccines and dendritic cell therapy at the Roswell Park Comprehensive Cancer Center in Buffalo, New York, emphasizes that further tests will require a control group. This will show how patients who have undergone surgery and the vaccine are doing compared to those who have undergone surgery. Scientists will also need to find out which T-cell responses are associated with long-term positive outcomes, she points out.
You may be interested in:
- How many Poles were vaccinated against COVID-19 in the last week? And how do we compare with Israel?
- Enlarged lymph nodes – causes, symptoms, treatment [EXPLAINED]
- This is what skin cancer looks like. Symptoms that must worry you
The content of the medTvoiLokony website is intended to improve, not replace, the contact between the Website User and their doctor. The website is intended for informational and educational purposes only. Before following the specialist knowledge, in particular medical advice, contained on our Website, you must consult a doctor. The Administrator does not bear any consequences resulting from the use of information contained on the Website. Do you need a medical consultation or an e-prescription? Go to halodoctor.pl, where you will get online help – quickly, safely and without leaving your home.Now you can use e-consultation also free of charge under the National Health Fund.