A Study of EPI-7386 in Combination With Abiraterone Acetate Plus Prednisone, or Apalutamide in Metastatic Castration-resistant Prostate Cancer (mCRPC)

A Phase 1b Study of EPI-7386 in Combination With Abiraterone Acetate Plus Prednisone or Apalutamide in mCRPC (ARES: Androgen Receptor Eradication Study)

The purpose of this study is to determine safety, including dose limiting toxicities, and the recommended phase 2 dose (RP2D) of EPI-7386 in separate combinations with (a) abiraterone acetate plus prednisone or prednisolone (AAP) and (b) apalutamide (dose-finding) and to determine the antitumor activity of EPI-7386 in separate combinations with (a) AAP and (b) apalutamide (dose-expansion).

Inclusion Criteria:

• Histologically confirmed prostate adenocarcinoma
• Must be able to continue Gonadotropin-releasing hormone agonist (GnRHa) during the study if not surgically castrate
• Eastern Cooperative Oncology Group (ECOG) performance status grade of 0, 1, or 2
• Must be able to swallow oral medicines
• Contraceptive use by men (and female partners of men enrolled in the study who are of childbearing potential or are pregnant) (birth control) use should be consistent with local regulations regarding the use of contraceptive methods for participants participating in clinical studies
• Willing and able to adhere to the prohibitions and restrictions specified in this protocol

Exclusion Criteria:

• Known central nervous system (CNS) metastases
• Non-metastatic castration-resistant prostate cancer (CRPC) (biochemical or locoregional disease only) is excluded from trial participation
• Evidence of predominant neuroendocrine/small cell carcinoma features in archival or baseline tumor biopsy specimen(s)
• Symptomatic or impending spinal cord compression, except if participant has received definitive treatment and demonstrates evidence of clinically stable disease
• Known disorder affecting gastrointestinal absorption