Before starting treatment, patients will have tests and check-ups for up to 4 weeks. Then, treatment happens in cycles that last 6 weeks. Most people will have up to six cycles. After treatment, doctors will check on patients for about 3 years with visits every 12 weeks. Some early visits may take a long time, up to 6 to 12 hours.

There are different groups in the study:

• Doublet group: Gets two medicines (AMO959 and AAA617).
• Triplet group: Gets three medicines (AMO959, AAA617, and ARPI).
• Food-effect group: Tests how food changes AMO959 levels.

In each cycle, AAA617 is given on Day 1. AMO959 is taken twice a day from Day 2 to Day 15. The triplet group also takes ARPI every day.

The study is open-label, which means you and the doctors know which treatment you are getting.
Patients will have regular visits, blood and urine tests, heart checks (ECGs), and scans like CT, MRI, bone scans, and PSMA-PET.

This study is for adults who have prostate cancer that has spread and is called PSMA-positive metastatic castration-resistant prostate cancer (mCRPC). Doctors are checking if these adults can join the study and take part in the treatments.

To join this study, patients must have prostate cancer that is PSMA-positive. This is checked with a special scan called PSMA-PET. Patients must be 18 years or older. Doctors will look at medical history and test results to make sure the study is a good fit. During the study, patients will keep getting a treatment called androgen deprivation therapy (ADT) unless they have already had surgery to remove the source of male hormones.

This study is being done to see if different amounts of a medicine called AMO959 can be safely given with another treatment called AAA617, and sometimes with a third medicine (abiraterone or enzalutamide). These medicines are for prostate cancer that has a protein called PSMA. The first part of the study is mainly to check safety and find the best dose, not to prove how well the treatment works.