Anti-cancer vaccine promises victory over myeloid leukemia
Researchers from the Kimmel Cancer Center at Johns Hopkins University have developed an experimental vaccine capable of reducing the number of cancer cells in the body of patients with chronic myeloid leukemia, as well as destroying residual tumor cells resistant to the action of certain anti-cancer drugs.
Myeloid leukemia (Greek myelos – bone marrow and leukos – white), or myeloid leukemia is one of the forms of blood cancer in which the number of white blood cells increases in the blood (1 ml of a healthy person's blood contains from 4 to 10 thousand white blood cells, in the advanced stage of the disease their number can reach 200-400 thousand in ml). The disease is steadily progressing, exhaustion and anemia develop in its final stage. Treatment: chemotherapy, radiation therapy, general tonic, if necessary – blood transfusion.
The vast majority of patients suffering from chronic myeloid leukemia are bound to chemotherapy for the rest of their lives. A little more than 90% of them achieve remission, but 10-15% cannot withstand long-term use of chemotherapy drugs.
Gleevec (imatinib, Gleevec), one of the first targeted anticancer drugs that has successfully proven itself in the treatment of chronic myeloid leukemia, has a destructive effect on leukemic cells in the patient's body, however, many patients after chemotherapy still manage to detect a certain number of surviving cancer cells. These residual cells are a source of relapses, especially if chemotherapeutic treatment is discontinued.
In addition, among the side effects of therapy, patients have a reduced number of blood cells, fluid retention in the body, nausea and other disorders of the gastrointestinal tract, increased fatigue and a feeling of fatigue. Many patients complain that over time this condition negatively affects the quality of their life.
Glivec also cannot be taken during pregnancy, and since a third of patients suffering from chronic myeloid leukemia are people aged 20-30 years, many of them are ready to give up taking the drug in the hope of starting a family.
In a study published in Clinical Cancer Research, scientists made a vaccine from myeloid leukemia cells, which were previously irradiated to weaken their malignant potential, and genetically modified, "tuned" to the production of the cytokine GM-CSF – granulocyte-macrophage colony stimulating factor, a signaling substance that stimulates the immune system. The cells treated in this way retain antigens – specific molecules by which the immune system can identify myeloid leukemia cells and destroy not only the "bait", but also the real cancer cells circulating in the body.
The experimental vaccine was tested on 19 patients with chronic myeloid leukemia who had been taking the drug Glivek for at least a year. Patients received 10 intradermal injections every three weeks for a total of four times. During the six-year follow-up, 13 patients had a decrease in the number of remaining cancer cells, and in 12 of them this indicator reached a record low, and in seven it was not possible to detect traces of residual myeloid leukemia cells at all.
Patients who participated in the vaccine trial had almost no side effects – only slight swelling and pain at the injection site, muscle pain and a slight fever.
The authors of the study state that their goal is to eradicate every single cancer cell in the patient's body. However, since the trial was conducted among a limited number of patients and was not compared with traditional methods of treatment, the researchers cannot confidently say that this effect was achieved exclusively with the help of a vaccine. In order to confirm the results obtained and expand the application of the method, it is necessary to continue further research.
If successful, the development of an anti-cancer vaccine capable of relieving patients from lifelong dependence on chemotherapy will undoubtedly be a significant step in the development of advanced cancer treatment methods.
Ruslan Kushnir
Portal "Eternal youth" http://vechnayamolodost.ru based on The Sydney Kimmel Comprehensive Cancer Center: Early Tests Show Vaccine Appears to "Mop Up" Leukemia Cells15.01.2010