Inclusion Criteria:

- Histologically or cytologically confirmed prostate cancer with progressive disease
defined as either:

- 2 or more new lesions on bone scan or

- Progressive disease on computed tomography (CT)/magnetic resonance imaging (MRI)
according to Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria
or

- Rising prostate-specific antigen (PSA): PSA evidence for progressive prostate
cancer consists of a minimum PSA level of at least 2 ng/ml, which has
subsequently risen on at least 2 successive occasions, at least 2 weeks apart

- Evidence of castration resistance defined as disease progression despite a
testosterone level < 50 ng/dL (or surgical castration)

- Patients must have received prior docetaxel based chemotherapy for metastatic
castrate resistant prostate cancer (CRPC)

- Any prior therapy for castrate disease is acceptable except prior abiraterone, which
is excluded; a minimum washout of 28 days for any other anticancer therapy prior to
first dose of study drug is required

- Any other radiotherapy or radionuclide require 28-day washout prior to first
dose of study drug

- Denosumab or zoledronic acid are allowed

- Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1

- Total bilirubin =< 1.5 x the upper limit of normal

- Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase
[SGOT])/alanine aminotransferase (ALT) (serum glutamic pyruvate transaminase [SGPT])
=< 2.5 X institutional upper limit of normal

- Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

- Therapy with other hormonal therapy, including any dose of megestrol acetate
(Megace), finasteride (Proscar), dutasteride (Avodart), or any herbal product known
to decrease PSA levels (e.g., saw palmetto and PC-SPES), or any systemic
corticosteroid (other than prednisone =< 10 mg/day) within 4 weeks prior to first
dose of study drug

- Therapy with supplements or complementary medicines/botanicals within 4 weeks of
first dose of study drug is excluded with the following exceptions:

- Conventional multivitamin supplements

- Selenium

- Lycopene

- Soy supplements

- Inability to swallow capsules or known gastrointestinal malabsorption

- History of other malignancies, with the exception of adequately treated non-melanoma
skin cancer or adequately treated superficial bladder cancer or other solid tumors
curatively treated with no evidence of disease for >= 5 years from enrollment

- Blood pressure that is not controlled despite > 2 oral agents (systolic blood
pressure [SBP] > 160 and diastolic blood pressure [DBP] > 90 documented during the
screening period with no subsequent blood pressure readings < 160/100)

- Serum potassium (K)+ < 3.5 mmoL/L on more than one reading within the screening
period

- Serious intercurrent infections or non-malignant medical illnesses that are
uncontrolled

- Active psychiatric illness/social situations that would limit compliance with
protocol requirements

- New York Heart Association (NYHA) class II, NYHA class III, or IV congestive heart
failure (any symptomatic heart failure)

- Concurrent therapy with strong inhibitors or inducers of Cytochrome P450 (CYP)3A4 due
to concerning possible drug-drug interactions with abiraterone