Crossover pharmacokinetics (PK) study to assess oral administration of abiraterone acetate capsule and tablet formulations in fasted and fed states in patients with prostate cancer

5168 Background: Abiraterone acetate (A) is an oral compound with metabolites that selectively inhibit CYP 17(17OH/ 17,20 lyase), blocking adrenal androgen synthesis and exhibiting anti-tumor activity in castration resistant prostate cancer (CRPC). Methods: Patients were divided into fed or fasted groups, and treated at 1000mg/day as a single dose in either capsule or tablet formulation on day 1, then the opposite formulation one week later on day 8, and from day 15, continuous dosing of 1000mg of the tablet formulation. PK samples were taken pre-dose and 1, 2, 4, 6, 8, 24, 48 and 72 hr post dose on days 1 and 8. Statistical analysis employed a two- period crossover model, using non-compartmental analysis. Results: A was well tolerated and side effects readily managed by mineralocorticoid antagonists. Overall 31 patients were enrolled, with PK results from 19 patients presented here. Area under the curve (AUC), was not significantly different between the two formulations for either the fed (p=0.412) or th...