Blood test may predict prostate cancer drug response, avoiding painful biopsies

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Histologically or cytologically confirmed adenocarcinoma of the prostate * Able to swallow the study drug whole as a tablet * Willing to take abiraterone on an empty stomach * Willing to use a method of birth control with adequate barrier protection * Metastatic disease as documented by positive bone scan or metastatic lesions other than liver or visceral metastasis on CT, MRI * Asymptomatic or mildly symptomatic from prostate cancer * Surgically or medically castrated * Previous anti-androgen therapy and progression after withdrawal * Life expectancy of at least 6 months Exclusion Criteria: * Active infection or other medical condition that would make corticosteroid use contraindicated * Uncontrolled hypertension * Severe hepatic impairment * History of pituitary or adrenal dysfunction * Clinically significant heart disease as evidenced by myocardial infarction or arterial thrombotic events in the past 6 months, severe or unstable angina, or NYHA Class III or IV heart disease * Have any condition that, in the opinion of the investigator, would compromise the well being of the subject or the study or prevent the subject from meeting or performing study requirements * Have poorly controlled diabetes * Have a history of gastrointestinal disorders that may interfere with the absorption of the study agents * Have a pre-existing condition that warrants long-term corticosteroid use in excess of study dose * Have known allergies, hypersensitivity or intolerance to abiraterone acetate or prednisone or their excipients * Pathologic finding consistent with small cell carcinoma of the prostate * Liver, visceral organ or brain metastasis * Prior cytotoxic chemotherapy or biologic therapy for the treatment of CRPC * Radiation therapy for treatment of the primary tumor within 6 weeks of Cycle 1, Day 1 * Radiation or radionuclide therapy for treatment of metastatic CRPC tumor within 2 or 6 weeks, respectively, of Cycle 1, Day 1 * Previous treatment with ketoconazole for prostate cancer for greater than 7 days * Prior systemic treatment with an azole drug * Prior flutamide treatment within 4 weeks of Cycle 1, Day 1 * Bicalutamide, nilutamide within 6 weeks of Cycle 1, Day 1 * Active or symptomatic viral hepatitis or chronic liver disease * History of a different malignancy except for the following circumstances: disease-free for at least 5 years and deemed by the investigator to be at low risk for recurrence of that malignancy. Individuals with the following cancers are eligible if diagnosed and treated within the past 5 years: basal cell or squamous cell carcinoma of the skin * Administration of an investigational therapeutic within 30 days of Cycle 1, Day 1