Abiraterone Acetate and Prednisone With or Without Veliparib in Treating Patients With Metastatic Castration-Resistant Prostate Cancer

Inclusion Criteria

• Have a histologic or cytologic diagnosis of prostate cancer
• Have progressive metastatic castration-resistant prostate cancer, on androgen-deprivation therapy, based on at least one of the following criteria:
• PSA progression defined as 25% increase over baseline value with an increase in the absolute value of at least 2 ng/mL that is confirmed by another PSA level with a minimum of a 1-week interval with a minimum PSA of 2 ng/mL
• Progression of bidimensionally measurable soft tissue (nodal metastasis) assessed within one month prior to registration by a computed tomography (CT) scan or magnetic resonance imaging (MRI) of the abdomen and pelvis
• Progression of bone disease (evaluable disease) (new bone lesion[s]) by bone scan
• Agree to undergo a biopsy of at least 1 metastatic site for gene-fusion status analysis; adequate archival metastatic tissue can be used if available in lieu of a biopsy; patients will only be eligible for protocol therapy if the biopsy has tumor and the tissue is evaluable for ETS fusion status
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
• Have testosterone = 3,000/ul
• Obtained within 14 days prior to registration: Absolute neutrophil count (ANC) >= 1,500/ul
• Obtained within 14 days prior to registration: Platelet count >= 100,000/ul
• Obtained within 14 days prior to registration: Serum creatinine = = 50 mg/ml/hr/1.73 m^2 body surface area (BSA)
• Obtained within 14 days prior to registration: Potassium >= 3.5 mmol/L
• Obtained within 14 days prior to registration: Bilirubin within the institutional limits of normal
• Obtained within 14 days prior to registration: Serum glutamic oxaloacetic transaminase (SGOT) (aspartate aminotransferase [AST]) = = 10.0 g/dL hemoglobin (Hb) with no blood transfusion in the past 28 days
• Men must agree to use effective contraception during treatment and for at least 1 week after the last administration of therapy
• Patients must be able to take oral medication without crushing, dissolving, or chewing tablets
• Patients may have received prior radiation therapy or surgery; however, at least 21 days must have elapsed since completion of radiation therapy or surgery and patient must have recovered from all side effects at the time of registration
• Ability to understand and the willingness to sign a written informed-consent document that is approved by the local institutional review board

Exclusion Criteria

• Patients may not be receiving any other investigational agents; any prior investigational products must be stopped at least 14 days (2-week washout) prior to registration
• Patients who have had chemotherapy, radiotherapy or oral antifungal agents (ketoconazole, itraconazole, fluconazole) within 3 weeks prior to entering the study or those who have not recovered (e.g. back to baseline or grade 1) from adverse events due to agents administered more than 3 weeks earlier
• There is a potential drug interaction when abiraterone is concomitantly used with a cytochrome P450 family 2, subfamily D, polypeptide 6 (CYP2D6) substrate narrow therapeutic index (e.g., thioridazine, dextromethorphan), or strong cytochrome P450 family 3, subfamily A, polypeptide 4 [CYP3A4] inhibitors (e.g., atazanavir, erythromycin, indinavir, itraconazole, Ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole) or strong inducers (e.g., carbamazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine); caution should be used when patients are on one of these drugs
• Patients with history of active seizures are not eligible
• Patients with a history of pituitary or adrenal dysfunction, active or symptomatic viral hepatitis, or chronic liver disease are not eligible
• Patients with known brain metastases should be excluded from this clinical trial
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to ABT-888 or abiraterone
• Patients may continue