Evaluating the Addition of Elacestrant (Oral SERD) to Olaparib (PARP-inhibitor) in Patients With Advanced/Metastatic HR+/HER2- Breast Cancer

This study is looking for both men and women, aged 18 or older, who have been diagnosed with breast cancer that has spread or is locally advanced. Your cancer needs to be hormone receptor-positive and HER2-negative, and you must also have a specific inherited change in your BRCA1 or BRCA2 genes.

Before joining, you'll need to be well enough to take part, meaning you can largely carry out daily activities. You should not have serious health issues like active brain cancer or other severe conditions that could put you at high risk. You'll also need to have healthy bone marrow and kidney function.

Doctors will also need to review previous test results, including a sample of your tumour tissue, to make sure you fit all the study requirements. If you are a woman who could become pregnant, you'll need to use highly effective non-hormonal contraception.

If you decide to take part in this study, you will be randomly assigned to one of two groups. Two out of three people will receive both olaparib and elacestrant, while the other group will receive olaparib alone. Both drugs are taken by mouth every day. You will continue treatment for as long as it helps, or until you experience side effects that are too uncomfortable, or until the study ends.

Throughout the study, you'll have regular hospital visits. At the start of each treatment cycle, you will have blood tests to check your general health and how your body is handling the medication. Every three months, you'll have scans (like chest and abdominal CT scans) to check if the cancer is responding to treatment. You'll also be asked to complete questionnaires about your quality of life. If there are any concerns about your cancer growing, you might have extra scans. You can withdraw from the study at any time.