Lin H, Liu Q, Zeng X, et al. - A retrospective study was conducted to explore the survival outcomes of pembrolizumab (PEM) plus enzalutamide (ENZ) vs PEM alone in selected populations of men with previously untreated metastatic castration-resistant prostate cancer (mCRPC) harboring programmed cell death ligand-1 (PD-L1) staining. Researchers retrospectively identified consecutive men with previously untreated mCRPC harboring PD-L1 staining who had undergone treatment with PEM plus ENZ (PE) or PEM alone (PA) at our medical center from January 1, 2017 to January 31, 2021. They retrospectively examined a total of 302 men, 96 of whom were deemed to be ineligible per the exclusion criteria, leaving 206 men (PE: n = 100, median age 64 years [range, 43–85] and PA: n = 106, 65 years [range, 45–82]) who were eligible for the study. The results indicate that PEM added to ENZ treatment may significantly increase the survival benefits compared with PEM treatment alone regardless of tumor mutation status among selected populations of men with previously untreated mCRPC harboring PD-L1 staining. It has been recorded that the safety profile for PE plus ENZ tends to be manageable.