This randomized phase II trial studies the best way to give abiraterone acetate in treating patients with castration-resistant prostate cancer. Abiraterone acetate is effective in treating castrate resistant prostate cancer and is taken in the fasting state. However, the body's absorption of abiraterone is increased with food intake. This study will test the whether a lower dose of abiraterone taken with food has a similar effect on prostate specific antigen (PSA) compared to full dose taken fasting.
PRIMARY OBJECTIVES: I. To compare the pharmacodynamic effect of reduced dose (250mg daily) abiraterone acetate in the prandial state (250mg-Fed) to the full, standard 1000mg daily dose in the fasting state (1000mg-Fasting) as assessed by change in serum prostate-specific antigen (PSA). SECONDARY OBJECTIVES: I. To evaluate the effect of prandial states on plasma levels and the intra-patient pharmacokinetic variability of abiraterone acetate. II. To evaluate the safety profile of reduced dose abiraterone acetate taken in the prandial state. III. To evaluate the pharmacodynamic effect of reduced dose abiraterone acetate in the prandial state as assessed by reduction in the extra-gonadal androgen dihydroepiadrosterone sulfate (DHEA-S) and dihydroepiandrostenedione (DHEA). IV. To evaluate the effect of prandial state on time to disease progression (Working group criteria). OUTLINE: Patients are randomized to one of two treatment arms. ARM I: Patients receive abiraterone acetate orally (PO) daily first thing in morning after an overnight fast of at least 8 hours. ARM II: Patients receive abiraterone acetate PO daily within 30 minutes of a conventional low-fat breakfast. In both arms, courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Both arms will also be treated with prednisone 5mg twice daily. After completion of study treatment, patients are followed up within 30 days.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
72
Given PO
Emory University Winship Cancer Institute
Atlanta, Georgia, United States
University of Chicago
Chicago, Illinois, United States
North Shore University Health System
Evanston, Illinois, United States
Ingalls Memorial Hospital
Harvey, Illinois, United States
Illinois Cancer Care
Peoria, Illinois, United States
National University Hospital
Singapore, Singapore
Change in PSA Level
Data were analyzed on a log scale: log(week 12) - log(baseline) = log ratio. Smaller (more negative) values indicate a better outcome.
Time frame: From baseline to 12 weeks
Progression-free Survival (PFS)
Time to PSA progression (25% increase from baseline), radiographic progression, or death.
Time frame: Assessed up to 3 years
Adrenal Androgen Production (DHEA-S)
Extragonadal serum adrogen
Time frame: Cycle 4 (4 months)
Number of Participants With Adverse Events (AEs)
Patients with grade 3 or higher AE (CTCAE Version 4.03)
Time frame: Assessed up to 1 year
Peak Plasma Concentration of Abiraterone
Analyzed on a log scale due to skewness of distribution
Time frame: Up to 4 months
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