Research from the University of Oxford shows that the technology supporting the Oxford-AstraZeneca vaccine against Covid-19, combined with an immunotherapy approach, could help fight cancer.
The death rate from cancer may have been steadily decreasing for 25 years, in particular thanks to the improvement of treatments and diagnostic methods, these diseases still claim many victims each year (more than 157,000 in France in 2018). . Also, work is continuing around the world to identify one or more approaches to prevent or cure cancer. Some laboratories are focused on developing a vaccine. And there is progress.
A vaccine / immunotherapy combo
Recently, researchers at the University of Oxford developed a vaccine approach combined with immunotherapy. In tests in mice, the vaccine boosted the levels of anti-tumor immune cells, while immunotherapy made them more effective.
Recent advances in immunotherapy have led to unprecedented improvements in outcomes for patients with advanced cancers, notably through therapies targeting immune checkpoints (ABIs). These are ligand-receptor interactions that downregulate the function of effector T cells. Inhibition of these control pathways with monoclonal antibodies can enhance the priming of anti-tumor T cells and thereby restore their activity.
However, many patients do not respond to this type of treatment due to a lack of pre-existing anti-tumor cytotoxic T lymphocytes (CTLs). Here, the Oxford team developed a therapeutic vaccine to increase the levels of these cells in the body.
The serum, which is based on one of the same viral vectors used in the Oxford-AstraZeneca Covid-19 vaccine, was specifically aimed at increasing CD8 + T cell levels. These are primed to target two proteins called MAGE-A3 and NY-ESO-1, which only appear on the surface of cancer cells.
Impressive results in mice
In tests in mice, the vaccine did increase the levels of these cells, while immunotherapy allowed them to target tumors more aggressively. Together, these two approaches significantly reduced tumor size and improved subject survival rates compared to control mice or immunotherapy alone. Half of the mice in the test group were still alive after fifty days, while none of the mice in the control group survived more than thirty days.
“Our cancer vaccines elicit strong CD8 + T cell responses that infiltrate tumors and show great potential for improving the effectiveness of immune checkpoint blocking therapy and improving outcomes for cancer patients,” confirms Adrian Hill, co-author of the study.
Once these results have been validated, the Oxford researchers are now planning a first phase 1/2 a clinical trial. Offered to 80 patients with non-small cell lung cancer (NSCLC), it is expected to start at the end of the year.