A lung cancer vaccine represents a scientific advancement in the ongoing effort to combat one of the leading causes of cancer-related deaths globally. This innovative approach seeks to harness the body’s own defense mechanisms to either prevent the disease from developing or to treat existing cancerous cells. The goal is to train the immune system to recognize and eliminate lung cancer, much like traditional vaccines protect against infectious diseases. This research offers new avenues for intervention beyond conventional treatments.
Types of Lung Cancer Vaccines
Lung cancer vaccines generally fall into two main categories based on their intended purpose: prophylactic, or preventive, vaccines and therapeutic, or treatment, vaccines.
Prophylactic vaccines are designed for individuals at a high risk of developing lung cancer. An example includes the LungVax project, which utilizes technology similar to the Oxford/AstraZeneca COVID-19 vaccine. It is designed to activate the immune system to kill abnormal lung cells before they become cancerous.
Therapeutic vaccines, by contrast, are administered to patients who already have lung cancer. Their objective is to stimulate the immune system to recognize and attack existing cancer cells, working alongside or following other treatments. Examples include messenger RNA (mRNA) vaccines, such as mRNA-4157 (V940), which use mRNA from a person’s own lung cancer tumor antigens to activate the immune system. Another type involves dendritic cell (DC) vaccines, where a patient’s own immune cells are trained outside the body to recognize cancer proteins and then re-introduced to stimulate an immune response.
How Lung Cancer Vaccines Work
Lung cancer vaccines operate by leveraging the mechanisms of the human immune system, teaching it to identify and neutralize cancer cells. This process involves presenting specific markers, known as antigens, to immune cells, triggering a targeted response.
Cancer cells often display unique proteins on their surface, called neoantigens, which arise from mutations within the cell’s DNA. These neoantigens act as “red flags” that the immune system can recognize as foreign. Vaccines introduce these specific neoantigens, or instructions to create them, into the body. This exposure primes the immune system, particularly T-cells and B-cells, to remember and respond to these markers.
When the immune system encounters these antigens through vaccination, T-cells become activated to directly kill cancer cells, while B-cells produce antibodies that help mark cancer cells for destruction. For instance, mRNA vaccines provide the body’s cells with instructions to produce these tumor antigens, leading to immune system activation. Similarly, dendritic cell vaccines involve treating a patient’s own dendritic cells with proteins from lung cancer cells, so when these cells are returned to the body, they can activate other immune cells to fight the cancer.
Current Status of Lung Cancer Vaccine Research
The development of lung cancer vaccines is an active and evolving field, with numerous approaches undergoing investigation in clinical trials. Most of these vaccines are still in various stages of research and are not yet widely available for general use.
Clinical trials are structured in phases to assess safety and effectiveness. Phase I trials typically involve a small group to evaluate the vaccine’s safety and identify side effects. Phase II trials expand to a larger group to further assess safety and determine if the vaccine elicits an immune response. Phase III trials involve hundreds or thousands of participants to confirm effectiveness, monitor side effects, and compare it to existing treatments.
Several promising candidates are under investigation. For example, the BNT116 messenger RNA vaccine, similar to COVID-19 vaccines, is in an early phase I trial for non-small cell lung cancer (NSCLC) patients and a phase II trial in combination with an immune checkpoint inhibitor. Another approach involves oncolytic virus vaccines, which use specialized viruses that target and destroy cancer cells while sparing healthy ones, and are being studied in combination with other lung cancer treatments. Researchers also face challenges in identifying tumor antigens that are strongly immunogenic and in overcoming the immune-tolerizing environment of the lung.
Who Could Benefit from Lung Cancer Vaccines
The potential beneficiaries of lung cancer vaccines vary depending on whether the vaccine is designed for prevention or treatment.
Preventive lung cancer vaccines are primarily aimed at individuals at a high risk of developing the disease. This includes current and former smokers, particularly those aged 55-74, and individuals with a significant family history of lung cancer.
Therapeutic lung cancer vaccines are intended for patients who have already been diagnosed with lung cancer. These vaccines are often considered an additional treatment option, either alongside or following conventional therapies such as surgery, chemotherapy, or radiation. They may be relevant for patients with specific stages or types of lung cancer, such as certain forms of non-small cell lung cancer. Clinical trials for therapeutic vaccines may be an option for individuals whose current lung cancer therapy is no longer effective, or those who have undergone treatment and wish to prevent recurrence.