| Exclusion Criteria: | 1) Metastases in the brain or active epidural disease. (Note: patients with treated epidural disease are allowed);
2) Absolute granulocyte count < 1.5 K/microliters at Screening;
3) Platelet count < 100 K/microliters at Screening;
4) Hemoglobin < 9 g/dL at Screening. (Note: patients whose anemia has been corrected to a hemoglobin value >/= 9 g/dL with blood transfusion or erythrocyte stimulating products are allowed);
5) Bilirubin, alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 2 x the upper limit of normal at Screening. Patients with a history of Gilbert's syndrome who have a total bilirubin > 2 x the upper limiit of normal may be enrolled if the total bilirubin is < 3 mg/dL;
6) Creatinine > 2 mg/dL or an estimated creatinine clearance (CrCL) < 50 ml/min (based on the Cockcroft-Gault formula) at Screening;
7) History of another malignancy within the previous 5 years (other than curatively treated nonmelanomatous skin cancer);
8) Androgen receptor antagonists (i.e. bicalutamide, flutamide, nilutamide) or 5-α reductase inhibitors (finasteride, aminoglutethamide) or ketoconazole within 6 half-lives of the start of Study Drug treatment; Half-lives are as follows: bicalutamide 6 days; flutamide 6 hours; nilutamide 4 days; finasteride 8 hours; aminoglutethamide 15 hours; Ketoconazole 8 hours.
9) Use of estrogens within 3 weeks of the start of Study Drug treatment;
10) Use of herbal products that may decrease PSA levels (i.e., saw palmetto) or systemic corticosterioid greater than the equivalent of 10 mg of prednisone per day during the 4 weeks prior to screening or plans to initiate treatment with the above during the entire duration of the study;
11) Anticipated use of estrogens, 5-alpha reductase inhibitors, ketoconazole or androgen receptor antagonists during the duration of the trial;
12) Use of an investigational agent within the 4 weeks prior to the start of Study Drug treatment;
13) Radiation therapy within 12 weeks of the start of Study Drug treatment; Any condition that, in the opinion of the Investigator, would impair the patient's ability to comply with study procedures;
14) Any condition that, in the opinion of the Investigator, would impair the patient's ability to comply with study procedures;
15) Evidence of severe or uncontrolled systemic disease other than castration-resistant prostate cancer;
16) History of seizure, including any febrile seizure, loss of consciousness, or transient ischemic attack within 12 months of enrollment, or any condition that may predispose to seizure (e.g., prior stroke, brain arteriovenous malformation, head trauma with loss of consciousness requiring hospitalization).
17) Have used or plan to use from 30 days prior to enrollment through the end of the study the following medications known to lower the seizure threshold: Aminophylline/theophylline; Atypical antipsychotics (e.g., clozapine, olanzapine, risperidone, ziprasidone); Bupropion; Insulin; Lithium; Pethidine; Phenothiazine antipsychotics (e.g., chlorpromazine, mesoridazine, thioridazine); Tricyclic and tetracyclic antidepressants (e.g., amitriptyline, desipramine, doxepin, imipramine, maprotiline, mirtazapine). |