Ph II Study to Evaluate Olaparib With Abiraterone in Treating Metastatic Castration Resistant Prostate Cancer.

This is a 2-part study in patients with metastatic CRPC. Part A is an open-label safety run-in study to assess the safety, tolerability and PK of olaparib when given in addition to abiraterone 1000 mg once daily. Part B is a randomised, double-blind, placebo-controlled comparison of the efficacy, safety and tolerability of the dose of olaparib selected from Part A when given in addition to abiraterone, versus placebo in addition to abiraterone. Abiraterone is indicated in combination with prednisone or prednisolone for the treatment of patients with metastatic CRPC. Prednisone or prednisolone 5 mg bid will be administered with the abiraterone in this study, but throughout this protocol the treatment will be referred to simply as abiraterone. For Part A of the study, 15 to 18 evaluable patients (Cohorts 1 and 2) are planned to be enrolled from approximately 4 sites in approximately 1 or 2 countries, and a further 12 patients may be recruited into a 3rd cohort if necessary. For Part B of the study, approximately 140 patients who have received prior chemotherapy containing docetaxel will be randomised from approximately 40 sites in North America and Europe. Patients who have been dosed in Part A of the study may not participate in Part B.