Queensland scientists are helping to speed up the development of a new type of immunotherapy by discovering how it activates the immune system to fight cancer.
It’s hoped the antibody therapy – which entered phase I clinical trials in the United States in early 2019 – could in future treat a broad range of cancers.
The head of QIMR Berghofer’s Immunology Department, Professor Mark Smyth, and his colleagues have been testing the antibody, which was developed by US company Tizona Therapeutics.
The findings have been published today in the journal Cancer Discovery, a publication of the American Association for Cancer Research.
“This antibody is designed to block the activity of an enzyme called CD39, which sits on the surface of harmful inflammatory cells,” Professor Smyth said.
“Blocking CD39 with the antibody releases an extracellular chemical signal called ATP.
“In laboratory tests, we’ve shown that this sets off a chain of events that ultimately kills the cancer-promoting inflammatory cells and releases proteins – called cytokines – that help immune cells called T cells fight the cancer.
“In other words, the antibody eliminates some of the enemy soldiers and helps to rally the immune system’s own troops.
“We’ve shown that this is a new way we can target the immune system to fight cancer.”
It was already known that CD39 is the first enzyme in a cascade chain reaction that converts ATP into adenosine, a cancer-promoting and immune suppressing metabolite.
“In this study, we have shown in laboratory tests that inhibiting CD39 with an antibody helps to fight cancer, not just by stopping the generation of adenosine, but also through the immune-activating functions of extracellular ATP,” Professor Smyth said.
“Importantly, our laboratory tests have also shown that it works well in combination with existing immunotherapies.”
The team’s findings will help to guide the design of future clinical trials of antibodies targeting CD39.
The study was primarily funded by the National Health and Medical Research Council of Australia, the Melanoma Research Alliance and Tizona Therapeutics Incorporated.