Phase 1 Study of ACE-232 to Treat Patients With Metastatic Castration-Resistant Prostate Cancer

Inclusion Criteria:

• Provide written informed consent

• Metastatic Castration-resistant Prostate Cancer with ongoing androgen - deprivationtherapy (ADT) or have bilateral orchiectomy

• Difficult to treat or intolerant to standard treatment (post at least 1 line of NHAand 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, extensiveradiation therapy, or local radiation therapy within protocol-defined wash-outperiod;

• Concomitant use of medications or herbal supplements known to be moderate to strongCYP3A4 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 hepatitisB or C, or a known active tuberculosis.

• Other malignancies requiring treatment within 3 years prior to the first dose ofstudy drug

• Known allergy or hypersensitivity to any of the excipients of ACE-232.

• Has other medical conditions that at the discretion of the investigator interferewith safety or efficacy evaluation, or treatment compliance.