Introduction: Treatment strategy for inoperable and metastatic urothelial carcinoma (mUC) has been revolutionized by the introduction of programmed cell death protein 1 (PD-1) and programmed cell death protein ligand (PD-L1) antibodies. During the last 3 decades treatment options were limited to chemotherapy, making further treatment of patients whose disease progressed under ongoing therapy or who were ineligible to receive cytotoxic therapy in the first place, nearly impossible.
Evidence acquisition: Five antibodies including pembrolizumab (PD-L1 antibody), atezolizumab (PD-1 antibody), nivolumab (PD-1 antibody), avelumab and durvalumab (PD-L1 antibodies) have been approved in the treatment of advanced urothelial carcinoma in first- and second-line treatment setting. The objective of this review was to examine and compare the different cohorts and to discuss the quality of the respective studies in order to set up selection criteria for clinical decision making.
Evidence synthesis: So far pembrolizumab and atezolizumab have demonstrated overall survival (OS) benefit in phase II studies and have shown superiority over standard chemotherapy in phase III studies which has granted them approval in first and second-line treatment setting. Improved OS and durable responses were also seen in phase Ib/II non-randomized, single-arm trials conducted with nivolumab, avelumab and durvalumab and granting accelerated approval for second-line treatment. The huge advantage of immunotherapy and one of the reasons for its overall recognition is its good tolerability profile especially in comparison to chemotherapy.
Conclusions: Pembrolizumab has to be recommended in second-line therapy due to reporting in a phase III trial and OS survival benefit compared to chemotherapy control group. In cisplatin-eligible and treatment-naïve patients with visceral or liver metastases data also slightly favors pembrolizumab rather than atezolizumab.