Grant: Project Grant

Despite over a hundred years of research there is still no Health Canada/FDA approved drug that can be taken at the time of radiotherapy to improve treatment outcome without increasing side effects in non-cancer tissues. Radiotherapy improvements have largely been realized through technology advances with greater precision and normal tissue sparing, however further gains are becoming increasingly difficult to obtain. The obvious alternate approach to overcoming this plateau is through the development of drugs that are able to selectively increase tumour sensitivity to radiotherapy. We are developing a novel, non-toxic drug that is targeted to a broad range of cancers when combined with radiotherapy. The main premise behind its strategy is that radiation is most effective when it combines with oxygen to make damage more permanent. An important reason cancers are resistant to radiation is that they contain a subset of cells at a relatively low concentration of oxygen. These hypoxic cells are key to tumour regrowth after radiation and are extremely rare in normal tissues. Our drug is designed to only become active under hypoxia, making it selective to cancer tissues. Once activated the drug acts to prevent cells from using oxygen, thereby allowing oxygen to build up and be available to sensitize cancer cells to radiation damage. The project will progress development of this new class of novel compounds to achieve efficient and selective synergy with radiotherapy, and possibly with another class of novel anti-cancer metabolism inhibitors. Because half of cancer patients are treated with radiation the impact of even a modest improvement in response would be significant. Indeed, since the scope of the radiotherapy patient population is now global the potential for improvement of quality of life and increasing cancer cure rates could not be greater.