Funded by Lloyd Family Clinical Scholar Fund
The human immune response can not only eliminate infections caused by viruses, bacteria and fungi, but can also kill cancer cells. Immunity is mediated by white blood cells. Among the different types of white blood cells, killer T cells can eliminate cancer cells, whereas regulatory T cells and some types of macrophages can block anti-cancer immunity and actually support cancer growth. The ability of killer T cells to eradicate cancer cells can be blocked by “immune checkpoint” proteins within the tumor microenvironment. Drugs have been developed to inhibit immune checkpoints (CTLA-4, PD-1 and PD-L1); thereby releasing the “brakes” on killer T cells to fight cancer. Using a combination of immune checkpoint inhibitors more than half of patients with widespread melanoma can experience long-term remission and possible cure.
Unfortunately, immune checkpoint inhibitors have been largely unsuccessful in patients with advanced prostate cancer. To better understand why they are not more effective, Dr. Subudhi’s team has evaluated the immune profile of primary and metastatic prostate cancers. They have found that the bone metastatic site is a highly immunosuppressive environment. This likely accounts for the poor clinical responses seen in patients with metastatic prostate cancer treated with a single agent immune checkpoint inhibitor. The overall goal of Dr. Subudhi’s clinical trials program is to improve survival in patients with advanced prostate cancer by enhancing T cell functions while eradicating the immunosuppressive cells within the cancer. Ultimately, his aim is to make immunotherapies in prostate cancer as effective as they are in melanoma.