Petros Grivas, MD, PhD, of the Seattle Cancer Care Alliance, Seattle, WA, discusses a study, which is the first clinical trial to use genomic-based selection to identify patients with urothelial cancer who are likely to benefit from selective HDAC inhibition. Dr Grivas goes on to discuss how the study investigated the use of mocetinostat for treated, locally advanced/metastatic urothelial carcinoma at the American Society of Oncology (ASCO) 2019 Annual Meeting, held in Chicago, IL.