If you are found to be eligible to take part in this study, you will be assigned to Group 1 and receive apalutamide, abiraterone, and prednisone. After 8 weeks of receiving treatment in Group 1, you will then have blood (about 4 teaspoons) drawn for biomarker testing. The result of this biomarker test will determine whether you will continue the study in Group 2 or Group 3.