Phase Ib of Abiraterone Acetate Plus BEZ235 or BKM120 in Castration-resistant Prostate Cancer (CRPC) Patients

Inclusion Criteria: * Adult males ≥ 18 years old * Eastern Cooperative Oncology Group Performance Status ≤ 2 * Patient must have a castrate level of testosterone (\<= 50 ng/dL or 1.7 nmol/L). ( Castrate status must be maintained by continued GnRH analogues unless patient has undergone surgical orchiectomy). * Histologically or cytologically confirmed diagnosis of advanced or metastatic prostate cancer. * Advanced or metastatic castration-resistant prostate cancer progression after abiraterone acetate failure * Patients should have no more than 2 lines of prior chemotherapies including cytotoxic agents * Discontinuation of all anti-androgen, anti-neoplastic or investigational treatment \>= 4 weeks (6 weeks for bicalutamide). Exclusion Criteria: * Previous treatment with PI3K pathway inhibitors (e.g. PI3K, AKT, mTOR inhibitor), ketoconazole, CYP17 inhibitors (exception of AA), or enzalutamide. * Patient has active uncontrolled or symptomatic CNS metastases * Inadequately controlled hypertension (e.g. systolic blood pressure \>=160 mmHg or diastolic blood pressure \>=95 mmHg) * Patient has a QTcF \> 480 msec on the screening ECG (using the QTcF formula), has a short/long QT syndrome, or history of QT prolongation/Torsades de Pointes * Patient has impairment of gastrointestinal (GI) function or GI disease that may significantly alter the absorption of study drugs * Patient has a medically documented history of or active major depressive episode, bipolar disorder (I or II), obsessive-compulsive disorder, schizophrenia, a history of suicidal attempt or ideation, or homicidal ideation (e.g. risk of doing harm to self or others) * Patients who experienced dose reductions and/or treatment interruptions due to abiraterone acetate related toxicities (i.e. serious AEs, AEs, liver toxicities during abiraterone acetate treatment