Combining immune checkpoint inhibitors with a targeted tumor-suppressing treatment might help patients’ own immune systems fight prostate cancer, according to new findings published in the journal Cancer Immunology Research.
To multiply and spread, cancer cells must be able to escape the immune system. One way they do this is by making checkpoint proteins, which keep immune cells (called T cells) from killing cancer cells in the body. Immune checkpoint inhibitors work by blocking checkpoint proteins so T cells can find and kill cancer cells.
Checkpoint inhibitors are effective for many kinds of cancer, but they rarely work in prostate cancer, PCF-funded research has shown. One reason is that prostate cancer has high levels of PIM kinases, which also suppress immune killing of cancer cells. In the new study, the researchers found that high levels of PIM kinases, especially PIM1, causes resistance to immunotherapy.
When they added a drug that blocks PIM1 kinase to an immune checkpoint inhibitor, the combination suppressed prostate tumor growth in both laboratory and animal models. These are preliminary results that will need further study—but the findings are promising, the researchers wrote. Other studies are also looking at how PIM inhibitors can fight cancer and other diseases.
This study is an example of essential laboratory research that forms the basis for every new therapy that comes into the clinic. Learn about how immunotherapy is currently used in prostate cancer treatment here.
