In November 2016, the results of a phase III clinical trial with the protein cell death (PD)-1 inhibitor pembrolizumab for second-line treatment of metastatic urothelial carcinoma were published and showed an overall survival benefit in comparison with conventional chemotherapy with vinflunine, docetaxel, or paclitaxel. In a similar trial the PD-L1 antibody atezolizumab showed no significant benefit in comparison to chemotherapy in the subgroup of PD-L1-positive patients and, thus, missed its primary endpoint. For other PD-1/PD-L1 directed substances, large phase I/II trials reported data concerning response rates and overall survival. This substance class will most likely become the new treatment standard in second-line treatment of metastatic urothelial cancer. Currently, PD-1/PD-L1 inhibitors are also being tested within randomized phase III trials for first-line treatment using different approaches either as a monotherapy or a combination with conventional chemotherapy or cytotoxic T‑lymphocyte-associated protein (CTLA)-4 inhibitors. Whereas data from single-arm phase II clinical trials have already been published, preliminary phase III data are expected in 2018.
Keywords: Antibodies; Atezolizumab; Cisplatin; Combination therapy; Pembrolizumab.