Dietary Fat Levels and Abiraterone Acetate Uptake in Patients With Metastatic Hormone-Resistant Prostate Cancer

PRIMARY OBJECTIVES:

I. To assess the dietary effects of a low fat and high fat diet at a low abiraterone acetate
dose (250 mg) on drug levels compared to standard dose administered in a fasting condition.

SECONDARY OBJECTIVES:

I. To potentially guide decisions in the future to use low dose abiraterone in a fed state
and decrease overall cost.

II. To evaluate the potential relationship between esterase activity and abiraterone
metabolism in an exploratory analysis.

III. To determine the feasibility of using patient-collected dried blood spot (DBS) samples
for pharmacokinetic monitoring.

OUTLINE: Patients are randomized to 1 of 2 treatment arms.

ARM I: Patients receive standard dose abiraterone acetate orally (PO) once daily (QD) (held
on days 2, 3, 9, and 10), and low-dose abiraterone acetate PO QD on days 3 and 10. Patients
eat a low fat breakfast on day 3 and a high fat breakfast on day 10.

ARM II: Patients receive abiraterone acetate as in Arm I. Patients eat a high fat breakfast
on day 3, and a low fat breakfast on day 10.

Inclusion Criteria:

- Histologically confirmed adenocarcinoma of the prostate

- About to initiate or currently being treated with abiraterone acetate 1000 mg orally
once daily

- Clinically able to receive abiraterone acetate in the opinion of the investigator in
accordance with standard prescribing practices

- Ability to consume a low fat and high fat diet

- Expected duration of continuous abiraterone therapy > 8 weeks

- Signed and dated informed consent

Exclusion Criteria:

- Patients taking medications that strongly inhibit or induce cytochrome P450 (CYP)3A4
within 28 days prior to the start of the study will be excluded