(UroToday.com) Metastatic castration-resistant prostate cancer (mCRPC) remains a lethal disease despite the increased number of treatment options that have been Federal Drug Administration (FDA) approved in the past decade. Most recently, the PARP inhibitors olaparib and rucaparib were approved for men with mCRPC harboring certain gene alterations associated with homologous recombination deficiency. In this study, Dr. Rana McKay presented a phase 2 study of olaparib versus olaparib in combination with the cediranib, an oral antagonist of VEGF receptors 1-3. The rationale from this study comes from preclinical and clinical studies showing that anti-angiogenic agents can result in a hypoxic tumor environment that downregulates the expression of homologous recombination genes, as well as studies in other cancers showing antitumor activity of cediranib and olaparib in combination.