A Phase 1 Study to Assess the Safety, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of ACE-232 in Patients With Metastatic Castration-Resistant Prostate Cancer (CRPC)

Inclusion Criteria: * Provide written informed consent * Metastatic Castration-resistant Prostate Cancer with ongoing androgen - deprivation therapy (ADT) or have bilateral orchiectomy * Difficult to treat or intolerant to standard treatment (post at least 1 line of NHA and taxane-based chemo in mHSPC or mCRPC), suitable for investigational treatment; * Has Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Has a life expectancy of at least 6 months * Adequate organ function and bone marrow function Exclusion Criteria: * Receiving any anti-cancer drugs or other treatment, major surgery, extensive radiation therapy, or local radiation therapy within protocol-defined wash-out period; * Concomitant use of medications or herbal supplements known to be moderate to strong CYP3A4 inhibitors/inducers, or P-gp inhibitors, known to prolong the QT interval. * Any previous treatment-related toxicities have not recovered. * Spinal cord compression or known brain metastases or leptomeningeal carcinomatosis. * Severe cardiovascular disorders. * Known gastrointestinal (GI) disorder or GI procedure * History of gastric and duodenal perforation. * History of pituitary dysfunction. * Poorly controlled diabetes mellitus. * Active or uncontrolled autoimmune disease * Active infections, or a known history of HIV infection, or a known active hepatitis B or C, or a known active tuberculosis. * Other malignancies requiring treatment within 3 years prior to the first dose of study drug * Known allergy or hypersensitivity to any of the excipients of ACE-232. * Has other medical conditions that at the discretion of the investigator interfere with safety or efficacy evaluation, or treatment compliance.