The European Medicines Agency have announced their recommendation to restrict the use of pembrolizumab and atezolizumab to the first-line treatment of urothelial cancer patients with high PD-L1 expression. Here, Thomas Powles, MBBS, MRCP, MD, from Barts Cancer Institute, London, UK, explains the reasoning behind this development, and shares his insights on why this is a positive movement towards more personalized treatment for patients. This interview was recorded at the American Society of Oncology (ASCO) 2018 Annual Meeting, held in Chicago, IL.