Biomarker-driven immunotherapy for precision medicine in prostate cancer

Although immunotherapy has recently revolutionized standard of care in different cancer types, prostate cancer has generally failed to show dramatic responses to immune checkpoint inhibitors. As in other tumors, the goal in prostate cancer is now to target treatments more precisely on patient's individual characteristics through precision medicine. Defects in mismatch repair, mutations in the exonuclease domain of the DNA polymerase epsilon (POLE), high tumor mutational burden and the presence of biallelic loss of CDK12 among others, are predictive biomarkers of response to immunotherapy. In the present review, we summarize the evolving landscape of immunotherapy in prostate cancer, including precision approaches and strategies to define classes of responsive patients and scale up resistance to immune checkpoint inhibitors.