The TOPARP study showed the beneficial utility of olaparib in a heavily pretreated population of metastatic castration-resistant prostate cancer who were biomarker-positive for aberrations in DNA repair gene.A higher response rate to olaparib of 88％ (14 out of 16 patients),time to radiographic progression as well as overall survival,was seen in patients who were biomarker-positive compared to those who were not.This study showed a promising way of targeting prostate cancer with an enriched population of patients who harbor these deleterious genes.This paves the way for offering new therapeutic opportunities for men who have otherwise few remaining options.