Olaparib is a treatment option for patients with mCRPC and a pathogenic mutaion (germline /somatic) in a homologous recombination repair gene (BRCA1, BRCA2, ATM, BADR1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D or RAD54L) who have been treated with androgen-receptor therapy.