A Study to Evaluate the Safety and Efficacy of Relugolix in Men With Advanced Prostate Cancer

Inclusion Criteria

• Has histologically or cytologically confirmed diagnosis of adenocarcinoma of the prostate.
• Is a candidate for, in the opinion of the investigator, at least 1 year of continuous androgen deprivation therapy for the management of androgen-sensitive advanced prostate cancer with 1 of the following clinical disease state presentations:
• Evidence of biochemical (PSA) or clinical relapse following local primary intervention with curative intent, such as surgery, radiation therapy, cryotherapy, or high-frequency ultrasound and not a candidate for salvage treatment by surgery; or
• Newly diagnosed androgen-sensitive metastatic disease; or
• Advanced localized disease unlikely to be cured by local primary intervention with either surgery or radiation with curative intent.
• Has a serum testosterone at the Screening visit of ≥ 150 ng/dL (5.2 nanomoles [nmol]/liter [L]).
• Has a serum PSA concentration at the Screening visit of > 2.0 ng/milliliter (mL) (2.0 microgram [μg]/L), or, when applicable, post radical prostatectomy of > 0.2 ng/mL (0.2 μg/L) or post radiotherapy, cryotherapy, or high frequency ultrasound > 2.0 ng/mL (2.0 μg/L) above the post interventional nadir.
• Has an Eastern Cooperative Oncology Group performance status of 0 or 1 at initial screening and at baseline. Key

Exclusion Criteria

• In the investigator's opinion, is likely to require chemotherapy or surgical therapy for symptomatic disease management within 2 months of initiating androgen deprivation therapy.
• Previously received gonadotropin-releasing hormone analog or other form of androgen deprivation therapy (estrogen or antiandrogen) for > 18 months total duration. If androgen deprivation therapy was received for ≤ 18 months total duration, then that therapy must have been completed at least 3 months prior to baseline. If the dosing interval of the depot is longer than 3 months, then the prior androgen deprivation therapy must have been completed at least as long as the dosing interval of the depot.
• Previous systemic cytotoxic treatment for prostate cancer (for example, taxane-based regimen).
• Metastases to brain per prior clinical evaluation.
• Participants with myocardial infarction, unstable symptomatic ischemic heart disease, cerebrovascular events, or any significant cardiac condition within the prior 6 months.
• Active conduction system abnormalities.
• Uncontrolled hypertension.