A Study of ARV-766 Given by Mouth in Men With Metastatic Castration-resistant Prostate Cancer Who Have Progressed on Prior Approved Systemic Therapies

Inclusion Criteria:

Part A and B:

Histological, pathological, or cytological confirmed diagnosis of adenocarcinoma of the prostate.
Progressive mCRPC
Ongoing androgen deprivation therapy (ADT) with a gonadotropin releasing hormone analog or inhibitor, or orchiectomy (surgical or medical castration).
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

Part A:

• Progression on at least 2 prior approved systemic therapies for metastatic prostate cancer (at least one must be a second-generation androgen inhibitor, e.g., abiraterone, enzalutamide, darolutamide, apalutamide).

Part B:

Participants must have received at least one but no more than three prior second generation anti-androgen agents (e.g., enzalutamide or abiraterone).
Participants must have received no more than two prior chemotherapy regimens.

Exclusion Criteria:

Part A and B:

Known symptomatic brain metastases requiring steroids (above physiologic replacement doses).
Active inflammatory gastrointestinal disease, chronic diarrhea, known diverticular disease, or previous gastric resection or lap band surgery.
Radiation therapy within 4 weeks of first dose of study drug or prior irradiation to >25% of the bone marrow.
Receipt of an investigational drug(s) within 4 weeks prior to anticipated first dose
Systemic anti-cancer therapy within 2 weeks of first dose of study drug (except agents to maintain castrate status). For bicalutamide, mitomycin C, or nitrosoureas the exclusion period must be 6 weeks and for abiraterone 4 weeks.