Promising Cancer Vaccine in Development
A new universal cancer vaccine could enhance the immune system’s ability to fight tumors and potentially amplify the effectiveness of current cancer treatments, according to an animal study.
Much like vaccines that protect against viral infections such as the flu, many cancer vaccines aim to help the immune system identify specific proteins. However, while standard vaccines focus on preventing diseases, cancer vaccines are being developed to eliminate existing cancers and prevent recurrence.
Despite their differences, traditional vaccines and cancer vaccines have similar mechanisms. For example, the flu vaccine helps the immune system recognize unique proteins on influenza viruses, while cancer vaccines train immune cells to identify distinct features of cancer cells.
Yet, there’s a significant hurdle: the cancer proteins of interest are often unique to individual patients, meaning many vaccines need to be custom-made. Personalizing these vaccines can be time-consuming, during which a patient’s cancer may mutate, possibly rendering the vaccine ineffective.
“There can be a delay of months from obtaining a patient’s sample to receiving personalized therapy,” noted Dr. Elias Sayour, a pediatric oncologist at the University of Florida Health. He and his team are exploring the possibility of creating a cancer vaccine that doesn’t require such personalization but instead generates a broad immune response to combat cancer.
“The notion that something could be readily available, albeit in a general way, could really change how therapies are implemented and how we manage patients,” Sayour commented.
An “Off-the-Shelf” Cancer Vaccine
The experimental vaccine, outlined in a study published recently in the journal Nature Biomedical Engineering, utilizes messenger RNA (mRNA), a technology also used in the initial COVID-19 vaccines.
The mRNA serves as a guide for cells to produce specific proteins. In the case of the vaccine, it instructs the body to enhance its first-line immune defenses by activating the “innate” immune system rather than relying on the “adaptive” system.
This vaccine particularly aims to increase the production of type-I interferons—key proteins that manage inflammation and help identify and eliminate cancerous tumors. Experiments done on lab mice indicated that these signals are crucial for detecting tumors early and promoting an immune response, and blocking these signals can lead to uncontrolled tumor growth.
Furthermore, the experiments revealed that this early interferon activity is essential for a common cancer treatment known as immune checkpoint inhibitors, which allow immune cells to function more effectively against cancer.
Cancer has its ways to dodge these interferon signals, making the proposed vaccine act as an immune “reset,” Sayour explained.
The researchers paired the vaccine with a checkpoint inhibitor in mouse models of melanoma, observing better results than with checkpoint inhibitors alone in mice with treatment-resistant tumors. The vaccine also showed promising anti-cancer effects when used on its own against other types of cancers like glioma (brain cancer) and pulmonary osteosarcoma (lung cancer).
In this preliminary research, they tested several mRNA formulations to stimulate the interferon response, noting that each was effective. More in-depth studies are necessary to determine whether the mRNA itself or the proteins it instructs to produce are more critical for generating this generalized response.
While the initial study focused on solid tumors, which typically resist immunotherapy more than blood cancers, Sayour expressed optimism that this approach could be applicable to all cancer types and act as a preventive measure against recurrence.
“This innovative study provides encouraging evidence that a timely boost to the immune system can help tumors that previously did not respond become sensitive to immunotherapy,” commented Diana Azzam, an associate professor at Florida International University, who was not involved in the study.
Azzam emphasized that this method may be especially beneficial for “cold” tumors—cancers that usually elude strong immune responses—such as those in the pancreas or ovaries.
“Although further research is necessary to understand its efficacy in humans, encouraging results in mice lay a solid foundation,” Azzam added. It’s crucial to ensure that the vaccine promotes a beneficial immune response without causing long-term inflammation.
In the meantime, Sayour and his team have initiated a human trial testing a two-step approach: administering an off-the-shelf vaccine followed by a personalized one, focusing on patients with recurrent pediatric high-grade glioma or osteosarcoma.
“This method is designed to save critical time needed for personalized options and may rapidly boost immunity that can be harnessed by tailor-made therapies,” Sayour explained.
