Petros Grivas, MD, PhD, University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA, outlines the rationale and study design of PATRIOT II, an ambispective, observationa, multicenter, two cohort study of avelumab first-line maintenance therapy in patients with locally advanced or metastatic urothelial carcinoma in the United States. This interview took place at the American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium 2022 in San Francisco, CA.