Safety, Pharmacokinetic and Proof-of-Concept Study of ARN-509 (Apalutamide) in Castration-Resistant Prostate Cancer (CRPC)

The purpose of this study is to assess the safety and activity of ARN-509 in men with advanced castration resistant prostate cancer. Patients will first be enrolled into Phase 1 of the study to identify a tolerable dose for the Phase 2 portion of the study. In the Phase 2, 3 different cohorts of patients will be enrolled to evaluate the safety and activity of ARN-509.

NON-METASTATIC CRPC Inclusion Criteria 1. Histologically or cytologically proven prostate cancer with high risk for development of metastases, defined as either a PSA value \>=8 ng/mL within the last 3 months or PSA Doubling Time \ 450 msec 8. History of seizure or condition that may predispose to seizure 9. Evidence of severe or uncontrolled systemic disease or HIV infection METASTATIC CRPC, TREATMENT-NAIVE Inclusion Criteria 1. Histologically or cytologically proven prostate cancer with progressive disease based on either PSA or radiographic progression 2. Ongoing androgen depletion therapy with a Gonadotropin Releasing Hormone (GnRH) analogue or inhibitor, or orchiectomy (i.e., surgical or medical castration) 3. Castrate levels of serum testosterone of less than or equal to 50 ng/dL 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 5. A life expectancy of at least 3 months Exclusion Criteria 1. History of, or current metastases in the brain or untreated spinal cord compression 2. Prior treatment with MDV3100 3. Prior treatment with abiraterone 4. Prior treatment with ketoconazole 5. Concurrent treatment with medications known to have seizure potential 6. Concurrent treatment with corticosteroids. If they are already on steroids, patients will be allowed to enroll on the study but will need to taper off as soon as possible. 7. QTc \> 450 msec 8. History of seizure or condition that may predispose to seizure 9. Evidence of severe or uncontrolled systemic disease or HIV infection METASTATIC CRPC, CHEMOTHERAPY-NAIVE, POST-ABIRATERONE Inclusion Criteria 1. Histologically or cytologically proven prostate cancer with progressive disease based on either PSA or radiographic progression 2. Ongoing androgen depletion therapy with a Gonadotropin Releasing Hormone (GnRH) analogue or inhibitor, or orchiectomy (i.e., surgical or medical castration) 3. Castrate levels of serum testosterone of less than or equal to 50 ng/dL 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 5. A life expectancy of at least 3 months 6. Patients must have received a minimum of 6 months of abiraterone treatment prior to disease progression Exclusion Criteria 1. History of, or current metastases in the brain or untreated spinal cord compression 2. Prior treatment with MDV3100 3. Prior treatment with ketoconazole 4. Concurrent treatment with medications known to have seizure potential 5. Concurrent treatment with corticosteroids. If they are already on steroids, patients will be allowed to enroll on the study but will need to taper off as soon as possible. 6. QTc \> 450 msec 7. History of seizure or condition that may predispose to seizure 8. Evidence of severe or uncontrolled systemic disease or HIV infection