A Safety and Pharmacokinetics Study of Niraparib Plus an Androgen Receptor-Targeted Therapy in Men With Metastatic Castration-Resistant Prostate Cancer (BEDIVERE)

Inclusion Criteria: * Histologically confirmed prostate cancer (mixed histology is acceptable, with the exception of the small cell pure phenotype, which is be excluded * At least 1 line of prior taxane-based chemotherapy * At least 1 line of prior androgen receptor (AR) targeted therapy * Progression of metastatic prostate cancer in the setting of castrate levels of testosterone or history of bilateral orchiectomy at study entry * Eastern Cooperative Oncology Group Performance Status (ECOG PS) of lesser than or equal to \[\<=\]1 Exclusion Criteria: * Known brain metastases or history of seizure * Prior treatment with a poly (adenosine diphosphate \[ADP\] ribose) polymerase (PARP) inhibitor * Prior platinum-based chemotherapy for the treatment of prostate cancer * Known history or current diagnosis of myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) * Severe or unstable cardiovascular disease or uncontrolled hypertension * Left ventricular ejection fraction (LVEF) of lesser than \[\<\] 50 percent (%) as determined by multiple uptake gated acquisition (MUGA) or echocardiography during screening