Researchers Develop mRNA Vaccine That Stimulates Immune Response Against Cancer Tumors

Scientists at the University of Florida (UF) have developed an experimental mRNA vaccine that, when combined with standard immunotherapy drugs known as immune checkpoint inhibitors, produced a strong antitumor effect in mice, which could lead to a new way of treating cancer without relying solely on surgery, radiation or chemotherapy. The vaccine doesn’t target specific tumou proteins, but rather activates the immune system as if it were fighting a virus. This effect was achieved by boosting the expression of a protein called PD-L1 within tumors.

This study builds upon a breakthrough first-ever human clinical trial, which found an mRNA vaccine quickly reprogrammed the immune system to attack glioblastoma, an aggressive brain tumor. Among the most impressive findings in the four-patient trial was how quickly the new method, which used a “specific” or personalized vaccine made using a patient’s own tumor cells, spurred a vigorous immune system response to reject the tumor.

In the new study, the research team adapted their technology to test a “generalized” mRNA vaccine, meaning it was not aimed at a specific virus or mutated cells of cancer but engineered simply to prompt a strong immune system response. The mRNA formulation was made similarly to the COVID-19 vaccines, rooted in similar technology, but wasn’t aimed directly at the well-known spike protein of COVID.

If future studies in humans show similar results, the research could pave the way for a universal cancer vaccine that helps treat many types of difficult, treatment-resistant cancers.

“This finding is a proof of concept that these vaccines potentially could be commercialized as universal cancer vaccines to sensitize the immune system against a patient’s individual tumor,” said Elias Sayour, MD, PhD, a pediatric oncologist at UF Health and a McKnight Brain Institute investigator and co-leader of a program in immuno-oncology and microbiome research.