Additional Study Information: You are being asked to take part in this study because you have been diagnosed with advanced prostate cancer and the standard drugs to treat your disease (metastatic castration-resistant prostate cancer mCRPC) are no longer effective or no effective treatment is known for your type of cancer. This research study will test an investigational drug called CC-94676 (the study drug; also known as BMS-986365). "Investigational" means the study drug being tested has not been approved by the United States Food and Drug Administration (FDA). CC-94676 is a new experimental drug developed by the sponsor, Celgene Corporation. In your type of cancer, abnormal activity of a protein called the androgen receptor (AR) may cause some cancers to grow. CC-94676 works by destroying the AR proteins, which may slow cell growth or kill cancer cells. CC-94676 has been shown to slow cancer growth and kill cancer cells in laboratory studies. This study is the first time CC-94676 is being given to humans. The primary purpose of this clinical research study is to test, for the first time in people, the safety (any good or bad effects) of the new experimental drug, CC-94676. Additional purposes of the study are: to explore if CC-94676 can control your disease, to explore how long CC-94676 stays in your body (pharmacokinetic or PK testing), and to explore what effect CC-94676 has on biomarkers in your blood and tumor. This study also includes testing of your blood and tumor biopsy samples for biomarkers. Biomarkers are substances such as proteins, genes, and other molecules found in blood, other body fluids or tissues that tell us how the drug is working in your body.