Saruparib (AZD5305) Plus Camizestrant Compared With CDK4/6 Inhibitor Plus Endocrine Therapy or Plus Camizestrant in HR-Positive, HER2-Negative (IHC 0, 1+, 2+/ ISH Non-amplified), BRCA1, BRCA2, or PALB2m Advanced Breast Cancer

To join this study, you need to be an adult woman (before, during, or after menopause) or an adult man. You must have advanced breast cancer that doctors have identified as 'hormone receptor-positive' and 'HER2-negative'. It's also important that your cancer has a specific genetic change (mutation) in one of these genes: BRCA1, BRCA2, or PALB2. Your general health should be good enough to participate, meaning you can mostly carry out your daily activities.

There are several reasons why you might not be able to join. For example, if you have a history of certain serious blood conditions (like MDS/AML) or problems that make you bleed easily. You also can't have other serious or uncontrolled health issues like certain heart conditions, active infections (such as hepatitis B or C, HIV, or tuberculosis), or cancer in other parts of your body that has spread to your brain or spinal cord. If you've recently had major surgery or radiation treatment, or if you have severe sickness or gut problems, you might not be eligible.

If you join this study, you'll be randomly assigned to one of three treatment groups, like flipping a coin. You'll have a 2 in 5 chance of getting the saruparib and camizestrant combination, a 2 in 5 chance of getting a standard CDK4/6 inhibitor with endocrine therapy, and a 1 in 5 chance of getting a CDK4/6 inhibitor with camizestrant. You'll receive your assigned treatment until your cancer gets worse, you experience side effects that are too difficult to manage, or you decide you no longer wish to participate.

The study involves regular check-ups with the study team. These visits will include various tests such as blood tests, scans (like CT or MRI), and possibly heart tests to monitor how you're responding to the treatment and to check for any side effects. You'll be taking medications, likely in pill form, or as injections, depending on your assigned treatment. The total duration of your participation will depend on how you respond to the treatment and until one of the stopping criteria is met.