An Safety and Efficacy Study of Abiraterone Acetate in Participants With Advanced Prostate Cancer Who Failed Androgen Deprivation and Docetaxel-Based Chemotherapy

A Phase II Open Label Study of CB7630 (Abiraterone Acetate) in Patients With Advanced Prostate Cancer Who Have Failed Androgen Deprivation and Docetaxel-Based Chemotherapy

The purpose of this study is to assess the anti-tumor activities and safety of abiraterone acetate in participants with prostate cancer (a disease in which cells in the prostate gland [a gland in the male reproductive system found below the bladder and in front of the rectum] become abnormal and start to grow uncontrollably, forming tumors) who have failed taxane (docetaxel)-based chemotherapy.

This is an open-label (all people know the identity of the intervention), single arm, multicenter (when more than one hospital or medical school team work on a medical research study) study to evaluate the anti-tumor activities and safety of abiraterone acetate in participants with cancer who have failed taxane (docetaxel)-based chemotherapy. Abiraterone acetate 1000 milligram (mg) tablet or capsule will be administered orally (by mouth), once daily after an overnight fast until disease progression, lack of disease response after six 28-day cycles of treatment, or when unacceptable toxicity is encountered. Participants will be treated for up to 12 cycles. All participants will receive a concurrent low-dose glucocorticoid (such as prednisone 5 mg tablet twice daily/prednisolone 0.5 mg tablet once daily). Treatment will be continued in responding participants until death, or disease progression, or end of the study (which is Week 148). Efficacy will primarily be assessed through prostate specific antigen response according to Prostate Specific Antigen Working Group (PSAWG) criteria. Participants' safety will be monitored throughout the study. Participants who have completed 12 cycles of abiraterone acetate treatment, and continue to receive clinical benefit from such treatment, will be eligible to enter the extension study. Participants who enter the extension study will continue taking abiraterone acetate at the dose they were receiving at the end of the main study together with low-dose glucocorticoid. Efficacy and safety will be monitored throughout the extension study. Study treatment will end when the patient dies, is lost to follow-up, withdraws informed consent, experiences sustained side-effects, has disease progression, or the sponsor discontinues the extension study. After the end of study visit is completed for the extension study, participants will be followed every 12 weeks for survival for up to 3 years following entry into the extension study.

Inclusion Criteria:

• Histologically or cytologically confirmed adenocarcinoma (cancer that begins in cells that line certain internal organs and that have secretory properties) of the prostate, but not with neuroendocrine differentiation or of small cell histology
• Before chemotherapy for prostate cancer with regimen(s) containing paclitaxel or docetaxel
• Documented prostate-specific antigen (PSA) progression according to PSA working group eligibility criteria with a PSA greater than 5 nanogram per milliliter (ng/mL)
• Ongoing androgen deprivation with serum testosterone level of less than 50 nanogram per deciliter (ng/dL)
• Eastern Cooperative Oncology Group (ECOG) Performance Status of less than or equal to 2 (Karnofsky Performance Status greater than or equal 50 percentage)

Exclusion Criteria:

• Active or uncontrolled autoimmune disease that may require corticosteroid therapy
• Serious or uncontrolled co-existent non-malignant disease, including active and uncontrolled infection
• Uncontrolled hypertension
• Clinically significant heart disease as evidenced by a myocardial infarction in the past 12 months, severe or unstable angina, or New York Heart Association (NYHA) Class III or IV heart disease (participants with a history of atherosclerotic vascular disease requiring coronary or peripheral artery bypass surgery may be enrolled provided the surgery occurred at least 2 years before to enrollment and after consultation with a cardiologist to insure that the disease is stable)
• History of gastrointestinal disorders (medical disorders or extensive surgery) which may interfere with the absorption of the study medication