Marshall CH, et al. - In this multicenter retrospective review of 23 consecutive men, researchers quantified the comparative differential responses to poly ADP-ribose polymerase (PARP) inhibitors between males with BRCA1/2 vs those with ATM mutations. They achieved PSA₅₀ responses to olaparib in 76% of cases with BRCA1/2 vs 0% of subjects with ATM mutations (Fisher's exact test). A median progression-free survival (PFS) of 12.3 mo vs 2.4 mo for candidates with BRCA1/2 mutations vs those with ATM mutations (hazard ratio 0.17). They suggested exploration of alternative therapies for subjects with ATM mutations.