Study Comparing Orteronel Plus Prednisone in Participants With Chemotherapy-Naive Metastatic Castration-Resistant Prostate Cancer

Inclusion Criteria:

Each patient must meet all of the following inclusion criteria:

* Voluntary written consent
* Male patients 18 years or older
* Histologically or cytologically confirmed diagnosis of prostate adenocarcinoma
* Radiograph-documented metastatic disease
* Progressive disease
* Prior surgical castration or concurrent use of an agent for medical castration
* Either absence of pain or pain not requiring use of any opioid or narcotic analgesia in the 2 weeks prior to study entry
* Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
* Even if surgically sterilized, patients must practice effective barrier contraception during the entire study treatment and for 4 months after the last dose of study drug, OR abstain from heterosexual intercourse
* Meet screening laboratory values as specified in protocol
* Stable medical condition

Exclusion Criteria:

Patients meeting any of the following exclusion criteria are not to be enrolled in the study:

* Known hypersensitivity to orteronel, prednisone or gonadotropin-releasing hormone (GnRH) analogue
* Received prior therapy with orteronel, aminoglutethimide, ketoconazole or abiraterone
* Received antiandrogen therapy within 6 weeks for bicalutamide and 4 weeks for all others prior to first dose of study drug
* Continuous daily use of oral prednisone or oral dexamethasone for more than 14 days within 3 months prior to study
* Received prior chemotherapy for prostate cancer with exception of neoadjuvant/adjuvant therapy as part of initial primary treatment for local disease that was completed 2 or more years prior to screening
* Exposure to radioisotope therapy within 4 weeks of receiving first dose of study drug; exposure to external beam radiation within 2 weeks of start of screening until receiving the first dose of study drug
* Documented central nervous system metastases
* Treatment with any investigational compound within 30 days prior to first dose of study drug
* Current spinal cord compression, bilateral hydronephrosis or current bladder neck outlet obstruction
* Diagnosis or treatment of another malignancy within 2 years preceding first dose of study drug except nonmelanoma skin cancer or in situ malignancy completely resected
* Uncontrolled cardiovascular condition as specified in study protocol
* Known history of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C
* Unwilling or unable to comply with protocol
* Uncontrolled nausea, vomiting or diarrhea
* Known gastrointestinal disease or procedure that could interfere with oral absorption or tolerance of orteronel