Fred Tanneau/AFP
COVID-19 mRNA vaccines could trigger the next revolution in cancer treatment. Scientists have found that these vaccines can potentially help patients whose tumors do not respond well to traditional immunotherapy.
mRNA-based COVID-19 vaccines, which have saved 2.5 million lives worldwide during the pandemic, can help boost the immune system to fight cancer. That’s the conclusion of a new study last week in the journal Nature.
While developing mRNA vaccines for brain tumor patients in 2016, the team, led by pediatric oncologist Elias Sayour, discovered that mRNA can train immune systems to destroy tumors – even though mRNA is not linked to cancer.
Based on this discovery, it was hypothesized that mRNA vaccines designed to attack the SARS-CoV-2 virus, which causes COVID-19, could also have antitumor effects.
The team analyzed the clinical results of more than 1,000 patients with melanoma and advanced lung cancer, treated with a type of immunotherapy called immune checkpoint inhibitors. This treatment is a common approach that doctors use to train the immune system to destroy cancer. It does this by blocking a protein that tumor cells produce to deactivate immune cells, allowing the immune system to continue destroying the cancer.
Notably, who received the vaccine against Pfizer or Moderna mRNA-based COVID-19 within 100 days of initiating immunotherapy, was more than twice as likely to be alive after three yearscompared to those who did not receive either vaccine.
Surprisingly, patients with tumors that normally do not respond well to immunotherapy also saw very significant benefits, with improved almost five times higher in overall survival after three years.
This link between improved survival and receipt of an mRNA vaccine against COVID-19 remained strong even after controlling for factors such as disease severity and associated conditions.
To understand the underlying mechanism, animal models were used. COVID-19 mRNA vaccines have been found to act as an alarm, activating the body’s immune system to recognize and destroy tumor cells, overcoming cancer’s ability to disable immune cells. When combined, vaccines and immune checkpoint inhibitors coordinate to unleash the full power of the immune system to destroy cancer cells.
Why it’s important
Immunotherapy with immune checkpoint inhibitors has revolutionized cancer treatment in the last decade, producing cures in many patients who were previously considered incurable. However, these therapies are ineffective in patients with “cold” tumors that can avoid detection by the immune system.
The new findings suggest that mRNA vaccines may precisely deliver the spark that the immune system needs to transform these “cold” tumors into “hot”.
If this is confirmed in the next clinical trial, the team hopes that this widely available, low-cost intervention could extend the benefits of immunotherapy to millions of patients who would not otherwise benefit from this therapy.
What other investigations are being carried out
Unlike vaccines for infectious diseases, which are used to prevent an infection, therapeutic cancer vaccines are used to help train the immune systems of cancer patients to better fight tumors.
Currently, scientists work to create personalized mRNA vaccines for cancer patients. This involves taking a small sample of a patient’s tumor and using machine learning algorithms to predict which proteins in the tumor would be the best targets for a vaccine. However, this approach can be expensive and difficult to manufacture.
In contrast, the mRNA vaccines against COVID-1 do not need to be personalized, they are already widely available at low cost or free of charge worldwide, and can be administered at any time during a patient’s treatment.
New findings that mRNA COVID-19 vaccines have substantial antitumor effects bring hope that they may help extend the anticancer benefits of mRNA vaccines to everyone.
What’s next
To this end, the research team is preparing to test this treatment strategy in a clinical trial in lung cancer patients.
People who receive an immune checkpoint inhibitor will be randomly assigned to receive or not receive a COVID-19 mRNA vaccine during treatment.
This study will determine whether COVID-19 mRNA vaccines should be included as part of standard treatment for patients receiving an immune checkpoint inhibitor. Ultimately, this approach is expected to help many patients treated with immunotherapy – especially those who currently lack effective treatment options.
In an article in , the authors of the new study praise that this work exemplifies how a tool born out of a global pandemic can provide a new weapon against cancer and quickly extend the benefits of existing treatments to millions of patients.
By leveraging an already familiar vaccine in a new way, we hope to extend the life-saving benefits of immunotherapy to cancer patients who have previously been left behind.
