Abiraterone Acetate Formulation and Methods of Use

1 . A unit dosage form of abiraterone acetate, wherein a 500 mg dose of the unit dosage form is bioequivalent to a 1000 mg dose of Zytiga® in healthy male subjects in the fasted state.

2 . The unit dosage form of abiraterone acetate of claim 1 , wherein the ratio of the log of the geometric mean of the AUC (0-∞) for a 500 mg dose administered to healthy male subjects in the fasted state compared to a 1000 mg dose of Zytiga® administered to healthy male subjects in the fasted state is selected from: 0.6 to 1.4, 0.7 to 1.3, 0.8 to 1.2 and 0.9 to 1.1.

3 . The unit dosage form of abiraterone acetate of claim 1 , wherein the ratio of the log of the geometric mean of the C(max) for a 500 mg dose administered to healthy male subjects in the fasted state compared to a 1000 mg dose of Zytiga® administered to healthy male subjects in the fasted state is selected from: 0.6 to 1.4, 0.7 to 1.3, 0.8 to 1.2 and 0.9 to 1.1.

4 . The unit dosage form of abiraterone acetate of claim 1 , wherein the [D90] of the abiraterone acetate is greater than 300 nm and less than one of: 7500 nm, 7000 nm, 6000 nm, 5000 nm, 4500 nm, 4000 nm, 3000 nm, 2000 nm, 900 nm, 800 nm, and 700 nm.

5 . The unit dosage form of abiraterone acetate of claim 1 , wherein the [D50] of the abiraterone acetate greater than 100 nm and is less than one of: 3500 nm, 3000 nm, 2500 nm, 1600 nm, 1400 nm, 1200 nm, 1000 nm, 800 nm, 500 nm, 400 nm, and 300 nm.

6 . The unit dosage form of abiraterone acetate of claim 1 , wherein the [D4,3] of the abiraterone acetate is greater than 300 nm and less than one of: 7000 nm, 6000 nm, 5000 nm, 4000 nm, 3000 nm, 2500 nm, 2400 nm, 2200 nm, 2000 nm, 1900 nm, 1700 nm, 1500 nm, 1300 nm, 1100 nm, 900 nm, and 800 nm.

7 . The unit dosage form of abiraterone acetate of claim 1 , wherein the dissolution rate of the abiraterone acetate in the unit dosage form is such that when a sample containing 100 mg of abiraterone acetate is tested in 900 ml of pH 4.5 phosphate buffer with 0.1% sodium lauryl sulfate using USP Apparatus II at 75 rpm, at least 70% of the abiraterone acetate dissolves in between 5 and 15 min or between 5 and 10 min.

8 . The unit dosage form of abiraterone acetate of claim 1 , wherein the dissolution rate of the abiraterone acetate in the unit dosage form is such that when a sample containing 125 mg of abiraterone acetate is tested in 900 ml of pH 4.5 phosphate buffer with 0.12% sodium lauryl sulfate using USP Apparatus II at 75 rpm, at least 70% of the abiraterone acetate dissolves in between 5 and 15 min or between 5 and 10 min.

9 . The unit dosage form of abiraterone acetate of claim 1 containing 125 mg of abiraterone acetate.

10 . The unit dosage form of abiraterone acetate of claim 1 , wherein a 500 mg dose, upon oral administration to a population of healthy male subjects in the fasted state, provides a mean blood plasma Cmax of 50-120 ng/ml.

11 . The unit dosage form of claim 10 , wherein a 500 mg dose, upon oral administration to a population of healthy male subjects in the fasted state, provides a median blood plasma tmax of 1 to 2.5 hrs.

12 . The unit dosage form of abiraterone acetate of claim 1 , wherein a 500 mg dose, upon oral administration to a population of healthy male subjects in the fasted state, provides a mean blood plasma AUC (0-∞) of 240-650 h*ng/ml.

13 . The unit dosage form of claim 1 containing 125 mg of abiraterone acetate.

14 . The unit dosage form of abiraterone acetate of claim 1 , wherein the 90% confidence interval of the mean blood plasma Cmax is a value between 50 and 120 ng/ml when a 500 mg dose is administered to healthy male subjects in the fasted state.

15 . The unit dosage form of abiraterone acetate of claim 1 , wherein the 90% confidence interval of the mean blood plasma AUC (0-∞) is a value between 240 and 650 h*ng/ml when a 500 mg dose is administered to healthy male subjects in the fasted state.

16 . The unit dosage form of claim 14 containing 125 mg of abiraterone acetate.

17 . The unit dosage form of any of claim 1 further comprising an antioxidant.

18 . A unit dosage form of abiraterone acetate containing 125 mg of abiraterone acetate, wherein the median particle size of the abiraterone acetate, on a particle volume basis, is between 2000 nm and 100 nm.

19 . The unit dosage from of claim 18 , wherein the dissolution rate of the abiraterone acetate in the unit dosage form is such that when a sample containing 125 mg of abiraterone acetate is tested in 900 ml of pH 4.5 phosphate buffer with 0.12% sodium lauryl sulfate using USP Apparatus II at 75 rpm, at least 70% of the abiraterone acetate dissolves in between 5 and 15 min or between 5 and 10 min.

20 . The unit dosage form of claim 18 , wherein the 90% confidence interval of the mean blood plasma AUC (0-∞) is a value between 240 and 650 h*ng/ml when a 500 mg dose is administered to healthy male subjects in the fasted state.

21 . The unit dosage form of claim 18 , wherein the 90% confidence interval of the mean blood plasma Cmax is a value between 50 and 120 ng/ml when a 500 mg dose is administered to healthy male subjects in the fasted state.

22 . A method for treating castration resistant prostate cancer comprising administering to a patient in need thereof a daily 500 mg dose of a dosage form abiraterone acetate, wherein the 500 mg dose is bioequivalent to a 1000 mg dose of Zytiga® in healthy male subjects in the fasted state and a glucocorticoid.

23 . The method of claim 22 wherein the glucocorticoid is selected from the group consisting of prednisone, prednisolone and methylprednisolone.