Checkpoint inhibition: new treatment options in urologic cancer

Both urothelial (UC) and renal cell cancer (RCC) are highly immunogenic tumours. Recent advances in cellular immunity understanding have resulted in a successful new class of therapeutic agents. Interaction between the programmed cell death 1 (PD1) on regulatory T-cells (Treg) and programmed cell death 1 ligand (PDL1) on cancer cells inhibits an effective immune response and is an important mechanism for cancer cells to evade the immune system. Monoclonal anti-PD1 and anti-PDL1 antibodies inhibit this interaction and are called checkpoint inhibitors. As in non-small lung cancer and melanoma, these agents have shown to be highly active agents in UC and RCC. In metastatic or inoperable UC, no good second line therapy exists and checkpoint inhibitors have shown to be active. Multiple Randomized Clinical Trials (RCT) are underway both in second line and adjuvant settings which could change daily practice. In RCC, an anti-PD1 antibody, Nivolumab, has already proven to be effective in prolonging overall survival, and is included in current guidelines in metastatic RCC in second and third line. RCTs with other anti-PD1 and anti-PDL1 antibodies are ongoing both in metastatic and adjuvant setting. Checkpoint inhibitors have breathed new life into immunotherapy in urologic cancers and are rapidly being included in practice guidelines.