A trial looking at a new drug called AZD9833 for people with breast cancer (Serena 1)

This trial is for people with advanced breast cancer. This means that the cancer:

• has come back in the same place after treatment (locally recurrence)

• has spread to other parts of the body (metastatic)

It is for people whose breast cancer cells are sensitive to the hormone oestrogen (oestrogen receptor positive or ER positive). And does not have receptors for a protein called HER2 (HER2 negative).