Sequential therapies for advanced urothelial cancer: Hope meets new challenges

Switch Maintenance Therapy for Metastatic Urothelial Carcinoma

INTRODUCTION: While switch maintenance therapy is being increasingly investigated in solid tumors, it is a standard in only a few. We conducted a systematic review on switch maintenance therapy for metastatic urothelial carcinoma. EVIDENCE ACQUISITION: In this systematic review, we conducted a literature search in PubMed and Cochrane databases up to 2021, based on PRISMA statement guidelines. One hundred and fifty eight articles were identified and after a three-step selection process and six articles, using different agents were included in evidence synthesis. The primary end points were effect on overall survival, progression free survival, safety and tolerability. EVIDENCE SYNTHESIS: In the pre-immunotherapy era, targeted therapies like sunitinib, lapatinib and vinflunine were studied as switch maintenance therapy in metastatic urothelial carcinoma but did not show any overall survival benefit. Use of anti-PD-1/PD-L1 agents have shown promise as switch maintenance therapy; pembrolizumab showed improvement in progression free survival in a phase 2 trial and avelumab showed improvement in overall survival and progression free survival in the phase 3 JAVELIN Bladder 100 trial. CONCLUSION: Immunotherapy with anti-PD-1/PD-L1 agents has emerged as an effective switch maintenance strategy in patients with metastatic urothelial carcinoma. Intensification of the immunotherapy backbone in this setting can potentially further enhance outcomes. Emerging evidence shows a potential role of Poly (ADP-ribose) polymerase (PARP) inhibitors in this setting as well. Results from ongoing and planned studies will help us understand which switch maintenance approaches would be most effective for improving outcomes in metastatic urothelial carcinoma.

Immunotherapy in the Treatment of Urothelial Bladder Cancer: Insights From Single-Cell Analysis

Urothelial bladder cancer (UBC) is a global challenge of public health with limited therapeutic options. Although the emergence of cancer immunotherapy, most notably immune checkpoint inhibitors, represents a major breakthrough in the past decade, many patients still suffer from unsatisfactory clinical outcome. A thorough understanding of the fundamental cellular and molecular mechanisms responsible for antitumor immunity may lead to optimized treatment guidelines and new immunotherapeutic strategies. With technological developments and protocol refinements, single-cell approaches have become powerful tools that provide unprecedented insights into the kaleidoscopic tumor microenvironment and intricate cell-cell communications. In this review, we summarize recent applications of single-cell analysis in characterizing the UBC multicellular ecosystem, and discuss how to leverage the high-resolution information for more effective immune-based therapies.