Experimental Vaccine Aims to Prevent Lung Cancer
Viviana Cetola
Reporter, Life News Today
For the first time, an experimental vaccine designed to prevent lung cancer is being evaluated in a clinical trial in humans. LungVax, developed by researchers at the University of Oxford and University College London, is initially intended for people who are at an increased risk of developing the disease. The project represents a novel approach in the fight against one of the deadliest types of cancer because, rather than treating a tumor once it has developed, it seeks to prepare the immune system to recognize and eliminate abnormal cells before they become cancerous.
Lung cancer continues to be one of the leading causes of cancer death in the United Kingdom and accounts for approximately one fifth of all cancer deaths in the country. One of the greatest challenges is that it can develop for a considerable period without producing noticeable symptoms, which means that many cases are diagnosed after the tumor has already reached an advanced stage. Although treatments have improved and survival depends greatly on the type and stage of the tumor at the time of diagnosis, only about 10 percent of people diagnosed with lung cancer survive for ten years or longer.
The possibility of preventing some of these tumors before they appear is the fundamental idea behind LungVax. Cancer does not develop suddenly. Instead, cells can accumulate changes in their DNA over time until they acquire characteristics that promote uncontrolled growth. Some of these mutations produce altered proteins that can generate fragments known as neoantigens, which can be presented on the surface of cells and act as signals that allow the immune system to distinguish abnormal cells from normal ones.
LungVax seeks to take advantage of these biological differences to stimulate the body's natural defenses. The vaccine contains genetic instructions designed to teach the immune system to recognize certain antigens associated with abnormal cells, with the goal of triggering a T cell response against them. If these cells can be identified and destroyed early enough, researchers hope it may be possible to prevent some of them from continuing to accumulate changes that could eventually lead to the formation of a tumor.
The technology used by LungVax is related to the platform used to develop the Oxford and AstraZeneca COVID-19 vaccine. LungVax uses ChAdOx2, a modified adenoviral vector that delivers genetic information to cells and stimulates an immune response. The fundamental difference is that a vaccine against an infectious disease teaches the body to recognize components associated with an infectious agent, while LungVax is intended to direct the immune response against signals associated with cells that are undergoing changes linked to cancer.
Studies conducted before the clinical stage allowed researchers to observe an immune response against the selected targets, but this does not mean that LungVax has already been proven to prevent lung cancer in humans. The vaccine remains experimental, and one of the primary reasons for conducting this clinical trial is to determine how the human body responds to it. Researchers will primarily evaluate its safety, possible side effects and the cellular immune response produced by vaccination before considering studies involving much larger groups of people.
The first stage of the study will include a total of 40 participants divided into two groups of 20 people. The first group will consist of adults who have undergone surgical treatment for stage IA or IB non-small cell lung cancer and who remain at risk of recurrence or of developing a new tumor. The second group will include people identified as being at increased risk through England's National Health Service lung cancer screening program, but in whom imaging studies performed before enrollment in the trial have not detected cancer.
Participants will receive four doses of LungVax by intramuscular injection over a period of 18 months and will be followed for two years after their first vaccination. Researchers will carefully monitor possible adverse effects and measure the response of immune cells to the antigens included in the vaccine. If the initial results show an acceptable safety profile and a promising immune response, the research could later progress to larger studies designed to determine whether LungVax can actually prevent or delay the development of a new cancer or the recurrence of the disease.
The development of this vaccine has been made possible in part by years of research into the genetic evolution of lung cancer. Studies such as TRACERx have allowed scientists to follow the changes tumors undergo as they grow, accumulate mutations and, in some cases, spread to other parts of the body. This information has helped researchers better understand which alterations appear during the evolution of cancer and which of them could potentially become targets for a preventive immune response.
The idea of using vaccines to reduce the incidence of cancer is not entirely new, although LungVax represents a different strategy from preventive vaccines that are already in use. The human papillomavirus vaccine, for example, can prevent infections with types of HPV responsible for most cervical cancers and has produced a significant reduction in these cancers among vaccinated populations. LungVax, by contrast, does not attempt to prevent an infection that could later cause cancer, but instead seeks to teach the immune system to recognize characteristics of abnormal lung cells that may be progressing toward malignant transformation.
This difference makes LungVax an example of a new prevention strategy based on knowledge gained from genetics, immunology and tumor biology. If it is ultimately shown to be safe and effective, this type of vaccine could provide an additional tool in the future for certain individuals at particularly high risk. However, years of clinical research will be necessary to determine whether the immune response produced by the vaccine actually results in fewer cases of cancer and, eventually, a reduction in deaths caused by the disease.
Researchers also caution that a preventive vaccine would not replace the measures currently known to reduce the risk of lung cancer. Avoiding tobacco use and quitting smoking remain among the most important actions people can take to lower that risk. Even if LungVax produces favorable results, it would initially be intended for specific groups and should not be interpreted as protection that eliminates the risks associated with smoking.
The LungVax clinical trial represents an important but still early step toward the possibility of preventing certain cancers through an intervention directed at the immune system. The initial studies must answer fundamental questions about its safety and its ability to produce an appropriate immune response before its preventive effectiveness can be evaluated in larger populations. For now, its significance lies both in what it may eventually achieve and in the change in perspective it represents, attempting to intervene during the earliest stages of the biological process that leads to cancer, before a tumor capable of threatening a patient's life has developed.
Sources: University of Oxford, University College London, National Institute for Health and Care Research, ISRCTN registry and Cancer Research UK.
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