Radioprotectant May Also Be a Radiobooster
Initially studied for its radioprotective effects on healthy cells, avasopasem may also increase cancer cells’ response to radiation treatment, researchers reported (https://www.science.org/doi/10.1126/scitranslmed.abb3768) in Science Translational Medicine.
Avasopasem is an experimental therapy that’s shown promise in reducing the incidence of oral mucositis in patients receiving head and neck radiotherapy. The next phase of those studies began testing the drug’s effect on cancer cells to ensure it didn’t protect them, too.
In both in vitro and animal studies, administration of avasopasem directly before radiation considerably improved cancer cells’ response to that radiation treatment, particularly at a single high dose (e.g., stereotactic ablative radiotherapy). Some of the mice also received another avasopasem treatment for several days after the radiation dose, and several of their tumors disappeared completely. The effect was seen across various tumor types, including lung, pancreatic, and head and neck.
Avasopasem’s mechanism of action is its ability to convert free radicals into hydrogen peroxide. Because healthy cells can remove the excess hydrogen peroxide, the conversion protects them from free radicals’ DNA-damaging effects. But most cancer cells lack the proper enzymes to clear hydrogen peroxide, so the increased levels cause them to form even more free radicals.
The drug is currently in phase I and II trials in humans with lung or pancreatic cancer.
Get a comprehensive guide to radiotherapy in the ONS/ONCC Radiation Therapy Certificate Course online (https://www.ons.org/courses/onsoncc-radiation-therapy-certificate-course).