Orteronel in Treating Patients With Metastatic Hormone-Resistant Prostate Cancer

PRIMARY OBJECTIVES:

I. To assess the relationship between circulating tumor cell (CTC)-based androgen receptor (AR) expression level and >=-50% prostate-specific antigen (PSA) decline following 12 weeks of therapy with TAK-700 (orteronel).

SECONDARY OBJECTIVES:

I. To assess changes in PSA and CTC levels and time to PSA progression (best response, decline at 12 weeks as continuous variable, etc.) with or without prior docetaxel-based treatment.

II. To assess measurable disease response and time to radiographic disease progression for castration-resistant prostate cancer (CRPC) with or without prior docetaxel-based treatment.

III. To explore relationships between endocrine and clinical responses.

IV. To confirm the safety of TAK-700 administered without prednisone in patients with metastatic CRPC.

OUTLINE: Patients receive orteronel orally (PO) twice daily (BID) on days 1-28. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.