CFI-400945 is a new type of drug for breast cancer. Laboratory tests show that it works by blocking a specific protein called Polo-like Kinase 4 (PLK4) that is involved in cancer cell growth. CFI-400945 may slow down the growth of cancer cells or may cause cancer cells to die. This drug has been shown to shrink tumours in animals and has been studied in more than 60 patients. It appears to be well tolerated with few side effects. CFI-400945 seems promising but it is not clear if it can offer better results than standard therapy.~Durvalumab is a new type of drug for many types of cancer. Durvalumab is an immunotherapy drug and not a chemotherapy drug. Laboratory tests show that it works by allowing the immune system (PD-1 and PD-L1 interaction) to detect your cancer and reactivating the immune response. This may help to slow down the growth of cancer or may cause cancer cells to die. Durvalumab has been shown to shrink tumours in animals and has been studied in more than 6000 people. In laboratory studies, when used together with CFI-400945, results seem promising but it is not clear if it can offer better results than standard treatment alone. This is the first time that the combination of CFI-400945 and durvalumab has been tested in patients.
The purpose of this study is to find out the effect that CFI-400945 and durvalumab have on breast cancer.