A Comprehensive Review of Immunotherapy Clinical Trials for Metastatic Urothelial Carcinoma: Immune Checkpoint Inhibitors Alone or in Combination, Novel Antibodies, Cellular Therapies, and Vaccines.

Simple Summary: Metastatic urothelial carcinoma is sensitive to immunomodulation. Immune checkpoint inhibitors (ICIs) have been FDA approved for use as single agents to treat locally advanced or metastatic urothelial carcinoma (mUC) since 2016. Immunotherapy has a lower incidence of side effects and longer durability of response compared to chemotherapy. Most recently, both the first-line combinations of pembrolizumab plus enfortumab vedotin and of nivolumab plus gemcitabine plus cisplatin showed significant overall survival benefit over prior standard-of-care chemotherapy and will be the fifth and sixth new drug regimens approved for mUC in the past four years. Treatment options for mUC are expected to continue to rapidly evolve. Here, we summarize clinical trials of immunotherapy that have led to the current standard of care for mUC, then review clinical trials testing novel immunotherapeutic approaches. A comprehensive understanding of current clinical trials will enable anticipation of upcoming developments and future research directions for mUC. Urothelial cancer is an immune-responsive cancer, but only a subset of patients benefits from immune checkpoint inhibition. Currently, single-agent immune checkpoint inhibitors (ICIs) and the combination of pembrolizumab with the antibody–drug conjugate enfortumab vedotin are approved to treat patients with metastatic UC (mUC). Approval of first-line nivolumab in combination with gemcitabine and cisplatin is expected imminently. Many treatment approaches are being investigated to better harness the immune system to fight mUC. In this review, we summarize the landmark clinical trials of ICIs that led to their incorporation into the current standard of care for mUC. We further discuss recent and ongoing clinical trials in mUC, which are investigating ICIs in combination with other agents, including chemotherapy, antibody–drug conjugates, tyrosine kinase inhibitors, and novel antibodies. Lastly, we review novel approaches utilizing bispecific antibodies, cellular therapies, and vaccines. The landscape of immunotherapy for mUC is rapidly evolving and will hopefully lead to better outcomes for patients. [ABSTRACT FROM AUTHOR]