One day we may have a vaccine that prevents all types of cancer, especially more deadly types like lung cancer. This is an area of intensive medical research. For now, there are only three cancer vaccines approved by the US Food and Drug Administration. However, you may have read the news about a vaccine against lung cancer that was developed in Cuba under the name CIMAvax. Here’s what you need to know about this medicine.
What is a cancer vaccine?
Immune system it helps fight things that could make you sick, like bacteria or viruses. The vaccine increases the ability of your immune system to achieve this. This is important because cancer has a way of training the immune system so that it does not recognize tumor cells as harmful or non-aggressive cancer cells even though it recognizes them as a threat.
According to the National Cancer Institute, vaccines are called modifiers of the biological response, because they stimulate or restore the ability of the immune system to fight infections and diseases. Cancer vaccines can help prevent the development of cancer (preventive or prophylactic vaccines) or can cure cancer when it develops.
The FDA has approved two types of preventative vaccines, one for hepatitis B and the other for cancer associated with human papilloma virus (HPV). Hepatitis B virus can cause liver cancer and HPV (human papilloma virus) can cause cancer of the cervix, anal, vaginal, vulva and penis. The FDA has also approved a vaccine to treat prostate cancer.
In fact, there is no FDA-approved lung cancer vaccine, says Dr. David Carbone, a medical oncologist and director of the Oncology Center at Ohio State University’s Comprehensive Cancer Center.
CIMAvax lung cancer vaccine
Scientists at Cuba’s Center for Molecular Immunology have developed a vaccine against lung cancer called CIMAvax. Their studies showed that the vaccine was well tolerated and that patients were better off after receiving it. This claims Dr. Jorge Gomez assistant professor of medicine, hematology, and medical oncology at Mount Sinai Hospital in New York City. It should be noted that this doctor was not included in the research studies of the CIMAvax vaccine in Cuba.
CIMAvax is a vaccine against a molecule called EGFR. EGFR is a normal molecule found in both healthy cells and lung cancer cells. This molecule is particularly pronounced in some patients with lung cancer.
Dr. Gomez claims that in the 1990s, cancer researchers believed that EGFR could trigger the growth of lung cancer, so they developed drugs that targeted this molecule. This drug has no effect except in one specific case where the EGFR was significantly altered or mutated. “This has been a great success in the treatment of lung cancer, ie the recognition that some patients have abnormal EGFR that triggers cell growth.” says Dr. Gomez. In these patients, EGFR is always activated so that it continues to signal and stimulate growth. About 15% of patients with lung cancer, mostly non-smokers, had mutated EGFR. “We now have drugs that work significantly in this group of patients with lung cancer,” concludes Dr. Gomez.
However, Dr. Gomez claims that the CIMAvax vaccine stops the signaling of normal EGFR. In a clinical trial in Cuba designed to assess the efficacy and safety of the drug, 405 patients were randomly selected to receive the vaccine or not to receive it after completing 4 to 6 chemotherapy treatments. Participants who received at least 4 doses of CIMAvax survived an average of two months longer than patients who did not receive the vaccine. Unfortunately, Dr. Gomez says that was not a statistically significant difference. When the researchers used statistics in the analysis, they discovered a three-month increase in survival, which is still statistically very significant.
Studies outside Cuba
Because studies related to the CIMAvax vaccine have been performed outside the United States, the FDA will not use these results for approval for use in the United States. The Roswell Park Cancer Research Institute, located in New York, is currently enrolling participants in a two-part clinical trial in the U.S. for patients with stage IV lung cancer who have received chemotherapy and completed their first treatment.
The first phase is designed to test and study the appropriate dose of CIMAvax vaccine, the second phase is to treat patients with the vaccine to see how it works, says Dr. Gomez. In this study, participants will receive the CIMAvax vaccine in combination with the immunotherapeutic drug Opdivo, so this study is not a copy of a clinical trial conducted in Cuba. “The study in Roswell will not tell us whether the vaccine is better or not,” says Dr. Gomez. This is just a number that will show us how the CIMAvax vaccine works in combination with nivolumab (opdivo). We still need research to show if the vaccine can really improve the condition of cancer patients.
The CIMAvax vaccine is not the only lung cancer vaccine being studied in scientific studies in the United States. A clinical trial search found 160 studies related to the study of the lung cancer vaccine, although only about 19 are actively registered. However, Dr. Gomez claims that the tests did not give positive results.
U.S. clinical trials of the CIMAvax vaccine yielding encouraging results however do not predominate as a proven therapy. In the first set of data published in the Cuban Clinical Trial, there was no difference in overall survival.
Regardless of the clinical trial of the CIMAvax vaccine, the good news for patients with advanced lung cancer is that the pace of development of the therapy is drastically accelerating. Clinical trials are not just experiments on humans. Many therapies that were once in clinical trials have become a new way of treating cancer patients.