BISCAY (NCT02546661) is an open-label, randomized, biomarker-directed, phase 1b study of durvalumab in combination with targeted therapies in metastatic urothelial cancer. Here, Principal Investigator Thomas Powles, MBBS, MRCP, MD, Barts Cancer Institute, London, UK, discusses the data presented at the European Society for Medical Oncology (ESMO) 2019 congress in Barcelona, Spain.