Lowering cancer drug dose could open tumors to immunotherapy

Research undertaken at the Harry Perkins Institute of Medical Research in Perth has shown that administering anti-cancer drugs at a hundred-fold lower dose than standard protocols could improve the tumor’s response to immunotherapy.

Perkins Head of Cancer Microenvironment, Professor Ruth Ganss from the University of Western Australia (UWA), said the new research had shown an alternative path to high doses of anti-cancer drugs to fight tough cancers like melanoma, brain cancer or pancreatic cancer.

Prof. Ganss has dedicated her life to studying the microenvironment around solid tumors. This microenvironment consists of “sticky” support tissue and blood vessels that feed the cancer and make the tumor impenetrable to cancer-fighting drugs and immunotherapy.

Prof. Ganss’s latest research, published this week in the Journal of Clinical Investigation, showed that when the dose of anti-cancer drugs was considerably reduced, the tumor initially grew, but then the blood vessels surrounding the tumor normalized, allowing immunotherapy to penetrate the tumor and be more effective.

“The anti-cancer drugs we are interested in are already clinically approved, this opens the way for us to propose new dosing and timing protocols for patients,” said Prof. Ganss.

“Our clinical collaborators have been excited by the results that show an alternative method of administering drugs and immunotherapy together.

“The next stage in our research is a clinical trial where we will analyze tissue samples in patients with these hard-to-treat cancers.

“My team and I are excited to have found new ways of modulating cancer blood vessels with already clinically approved drugs, and now we can hopefully produce an outcome which lends itself to better, more effective treatments for the very sick and prolonging their lives.”

Two other researchers from the Perkins, Professor Jonas Nilsson, Head of Melanoma Discovery, and Professor Alistair Forrest, Head of Systems Biology and Genomics were among the research team, as well as scientists from the U.S. and Germany.