Immune checkpoint inhibitors in genitourinary malignancies
Although immune-mediated therapies have been used in genitourinary (gu) malignancies for decades, recent advances with monoclonal antibody checkpoint inhibitors (cpis) have led to a number of promising treatment options. In renal cell carcinoma (rcc), cpis have been shown to have benefit over conventional therapies in a number of settings, and they are the standard of care for many patients with metastatic disease. Based on recent data, combinations of cpis and antiangiogenic therapies are likely to become a new standard approach in rcc. In urothelial carcinoma, cpis have been shown to have a role in the second-line treatment of metastatic disease, and a number of clinical trials are actively investigating cpis for other indications. In other gu malignancies, such as prostate cancer, results to date have been less promising. Immunotherapies continue to be an area of active study for all gu disease sites, with several clinical trials ongoing. In this review, we summarize the current evidence for cpi use in rcc, urothelial carcinoma, prostate cancer, testicular germ-cell tumours, and penile carcinoma. Ongoing clinical trials of interest are highlighted, as are the challenges that clinicians and patients will potentially face as immune cpis become a prominent feature in the treatment of gu cancers.