Researchers at the University of Florida (UF) and MD Anderson Cancer Center report a convincing correlation between vaccination with mRNA COVID-19 vaccines and improved survival in patients receiving immunotherapy for certain cancers.
Main findings
A retrospective analysis of patient records revealed that patients with advanced lung or skin cancer who received an mRNA COVID-19 vaccine within 100 days of starting immunotherapy lived significantly longer than those who were not vaccinated.
In one cohort of patients with advanced non-small cell lung cancer, median survival for vaccinated patients was approximately 37.3 months, compared with approximately 20.6 months for unvaccinated patients.
Among patients with metastatic melanoma, the median survival for the 43 vaccinated patients had not yet been reached, while the median survival for the 167 unvaccinated patients was approximately 26.7 months. These preliminary results suggest that the vaccine may act not only as a prophylactic agent against SARS-CoV-2, but also as a stimulus that “stimulates” the immune system in a way that enhances cancer immunotherapy. According to senior investigator Elias Sayor, MD, this is a “defining moment in more than a decade of research…We will be able to design even better non-specific vaccines that mobilize and reset the immune response in a way that could essentially become a universal off-the-shelf cancer vaccine for all cancer patients.”
What does research tell us and what we don’t know?
Importantly, this study was retrospective and based on a review of medical records, so a causal relationship cannot be definitively proven. The authors emphasize that a randomized clinical trial is currently being planned to validate the study results.
Mechanistic studies in animal models support the hypothesis that mRNA vaccination causes activation of innate immunity, thereby enhancing the efficacy of immune checkpoint inhibitors (the type of drugs used in the immunotherapies studied). For example, in mouse models, an mRNA vaccine targeting the COVID-19 spike protein, when combined with checkpoint blockade, helped transform previously unresponsive tumors into responsive ones.
Potential impacts and things to be aware of
If verified, the implications would be significant. Widely available, low-cost mRNA vaccines may become a standard adjunct to immunotherapy, potentially increasing the number of patients who will benefit and expanding the scope of immunotherapy for cancers that currently have poor responses.
But experts warn that many factors remain unresolved.
Whether timing, cancer type, and immunotherapy regimen all influence the observed benefits. The precise biological mechanisms by which vaccine-immune system interactions improve tumor responses. Whether this effect is seen not only in advanced lung and skin cancers, but also in other cancers and broader patient populations.
This study by UF and MD Anderson provides exciting evidence that mRNA COVID-19 vaccines, when administered at the onset of immunotherapy, may significantly improve survival rates for certain cancer patients. Although still in its preliminary stages, this study opens up the possibility of repurposing common vaccine platforms in oncology, and if confirmed in prospective trials, this change could redefine how vaccinations and cancer treatments are combined.
The researchers cautioned that more research is needed and that patients should not base treatment decisions solely on this data. For now, this is a promising lead, not a new standard of care.
A team of researchers from the University of Florida and MD Anderson reported in an analysis of patient records (more than 1,000 patients) that cancer patients who received an mRNA COVID-19 vaccine within 100 days of starting immunotherapy lived significantly longer than those who did not.
Separately, university researchers published preclinical studies (in mice) of an experimental mRNA cancer vaccine (not a COVID-19 vaccine) in the journal Nature Biomedical Engineering.
