Clinical trials have begun around the world, to test an mRNA-based vaccine for lung cancer, relying on the same technology used in the development of the COVID-19 vaccines. Lung cancer is a significant global health challenge and the leading cause of cancer-related deaths.
Most patients are diagnosed when the disease is in its advanced stages and has already spread. Even with early diagnosis and surgery, the recurrence rate remains high.
The success of mRNA vaccines during the COVID-19 pandemic has opened the door to developing similar vaccines for lung cancer. This new approach aims to destroy tumor cells by mobilizing the immune system against the cancer, targeting the malignant cells without harming healthy tissue, and producing antibodies against cancer cells.
What does it mean to vaccinate against cancer?
mRNA, or messenger RNA, is a new technology that harnesses the immune system. An mRNA molecule carries instructions for producing a specific protein and is injected into the body like a vaccine. The mRNA enters cells and directs them to produce a protein that represents either the patient’s specific tumor or one linked to lung cancer. The immune system recognizes the protein, responds by killing cancer cells, and develops antibodies specifically against them.
Cancer is a complex disease. It grows and spreads by evading the immune system, effectively "hiding" from it. The vaccine reveals these hidden cancer cells, allowing the immune system to recognize and destroy them.
There are three main types of mRNA vaccines under development:
- Proteins that express a characteristic unique to lung cancer.
- Proteins that enhance the immune response against cancer.
- Proteins that target each patient’s specific tumor.
How does this method work?
Researchers isolate cancer cells from the body, sequence their DNA, and identify the unique proteins (called "neoantigens") of the tumor. Using computational models, researchers can predict which neoantigens are likely to trigger a strong immune response in each patient without causing the immune system to attack healthy cells. Once identified, the vaccine instructs the body’s cells to produce these proteins, essentially "teaching" the immune system to detect and destroy cancer cells that have disguised themselves.
What’s the connection between these vaccines and COVID-19 vaccines?
The COVID-19 pandemic accelerated the development of mRNA vaccine technology, which had been studied for many years, particularly for its potential in cancer treatment.
Can this vaccine prevent cancer from developing?
mRNA vaccines don’t prevent cancer but are designed to treat existing cancer or reduce the risk of recurrence. A recent study published in The Lancet showed a reduction in the recurrence rate of melanoma after surgery when the vaccine was used alongside an immune checkpoint inhibitor.
What are the main challenges in developing an effective cancer vaccine?
The biggest challenge lies in precisely targeting the correct neoantigens to provoke a strong immune response. Not all neoantigens elicit a sufficient immune reaction. Additionally, tumors consist of various types of cells, and metastatic tumors pose an even greater challenge. For example, a liver metastasis might differ from lung cancer cells, so not all tumor cells may respond to the vaccine. Despite these hurdles, this marks significant progress in combating cancer.
Dr. Talia Shentzer-KutielPhoto: Rambam Health Care CampusHow does the vaccine differ from other cancer treatments?
Immunotherapies generally stimulate the immune system to attack cancer cells more aggressively, but this can also lead to side effects, as an overactive immune response might harm healthy cells. Traditional cancer treatments like chemotherapy are less targeted, attacking fast-dividing cells, including healthy ones, which leads to side effects like hair loss and digestive issues.
In contrast, mRNA vaccine technology is far more specific. It activates the immune system to target only tumor cells, minimizing harm to healthy tissues. As a result, the risk of side effects with this vaccine is considerably lower than with other treatments.
When will these vaccines be available to patients in Israel?
The innovative mRNA-based cancer vaccines are currently in advanced research and development stages, but there is no exact timeline for when they will be widely available in Israel. If ongoing international and local trials continue to show positive results, these vaccines could become available in the coming years—a significant breakthrough for cancer patients in Israel as well.
The author is a senior physician and researcher specializing in lung cancer at the oncology department of Rambam Health Care Campus