A Study of Opevesostat (MK-5684) in China Participants With Metastatic Castration-Resistant Prostate Cancer (mCRPC) (MK-5684-001)

The main inclusion and exclusion criteria include but are not limited to the following:

Inclusion Criteria:

* Has histologically or cytologically confirmed adenocarcinoma of the prostate without small cell histology.
* Has prostate cancer while receiving androgen deprivation therapy (ADT), or post-bilateral orchiectomy, within 6 months before screening.
* Has evidence of progression \>4 weeks since last flutamide treatment or \>6 weeks since last bicalutamide or nilutamide treatment.
* Has evidence of metastatic disease documented by either bone lesions on bone scan and/or soft tissue shown by CT/MRI.
* Has disease that progressed during or after treatment with at least 1 line of next-generation hormonal agents (NHAs) for hormone-sensitive prostate cancer (HSPC) or castration-resistant prostate cancer (CRPC) for at least 8 weeks (at least 14 weeks for participants with bone progression).
* Has received at least 1 line of taxane-based chemotherapy for HSPC or CRPC and have had progressed disease during or on treatment, or refused or ineligible to receive chemotherapy.
* Has a life expectancy of \>3 months.

Exclusion Criteria:

* Has history of a second malignancy, unless potentially curative treatment has been completed with no evidence of malignancy for 3 years.
* Has presence of gastrointestinal condition, e.g. malabsorption, that might affect the adsorption of study intervention.
* Has a history of pituitary dysfunction.
* Has poorly controlled diabetes mellitus.
* Has active or unstable cardio/cerebro-vascular disease, including thromboembolic events.
* Has undergone major surgery, including local prostate intervention (except prostate biopsy), within 4 weeks of the date of allocation.
* Has received an anticancer monoclonal antibody (mAb) within 4 weeks of allocation, or has not recovered from adverse events (AEs) due to mAbs administered more than 4 weeks before the date of allocation.
* Received prior systemic anticancer therapy including investigational agents within 4 weeks before the date of allocation.
* Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any form of immunosuppressive therapy within 7 days prior to the start of study intervention.
* Has a known active central nervous system (CNS) metastases and/or carcinomatous meningitis.
* Has an active autoimmune disease that has required systemic treatment in the past 2 years.
* Has a history of or current human immunodeficiency virus (HIV) infection.
* Has a concurrent Hepatitis B or Hepatitis C virus infection.
* Has a history of allogenic tissue or solid organ transplant.