Avasopasem Shields Normal Cells from Radiation, Helps Kill Cancer Cells
What is the aim of Cancer treatments? Cancer treatments aim to kill cancer cells. Other treatments often used to help people with cancer, called supportive therapies, protect normal tissues or make the side effects from cancer treatments more bearable. What if one drug could play both of these roles at the same time? In new studies in mice, researchers found that a drug called avasopasem manganese (AVA), which has been found to protect normal tissues from radiation therapy, can also make cancer cells more vulnerable to radiation treatment. AVA provides this dual effect by exploiting the differences in the way normal and tumour cells produce hydrogen peroxide, explained Douglas Spitz, PhD, professor of radiation oncology at the University of Iowa, who helped lead the study. With any cancer treatment, “you try to find this sweet spot where you’re balanced between an effective therapeutic dose for killing cancer cells, but not causing excessive harm to normal tissues,” said Michael Espey, PhD, of NCI’s Division of Cancer Treatment and Diagnosis, who was not involved in the study. “If you can [have a single drug that] lowers the toxicity in normal tissues while increasing the toxicity in cancer cells, then you really have sort of a game-changer.” More work is needed to see if the effects observed in mice can be replicated in people. But in April, Galera Therapeutics, which manufactures AVA, reported positive findings from a small clinical trial of AVA added to a targeted form of radiation therapy in people with pancreatic cancer. Two other ongoing clinical trials are also testing AVA in combination with radiation therapy in lung and pancreatic cancer. Building on Cells’ Natural Defense Mechanisms In radiation therapy, high doses of x-rays or other charged particles are aimed at a tumour. The radiation can damage cancer cells’ DNA to the point where the cells stop dividing or die. While a single radiation dose is administered in minutes, many of the resulting changes in cells that cause them to die take days to occur. When a dose of radiation hits a cell, its high energy creates compounds called free…
