A Study to Learn About the Study Medicine (Called Avelumab) in People With Advanced Urothelial Cancer After Chemotherapy

The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called Avelumab) in people with advanced urothelial (bladder) cancer (UC) whose disease hasn't worsened after receiving chemotherapy. This study is seeking participants who: 1. Have UC that cannot be operated on or has spread to other parts of the body 2. Received 1st line platinum-based chemotherapy and had stable disease, partial response, or complete response to this treatment 3. Received Avelumab as indicated as the only therapy for the first-line maintenance who are progression-free following platinum-based chemotherapy 4. Are 18 years or older on the date that they start taking Avelumab All participants in this study will receive Avelumab, a standard treatment for urothelial carcinoma. Participants will take part in this study for about 4 years. During this time, they will take Avelumab as instructed in the real-world setting. We will study the experiences of people receiving the study medicine. This will help us decide if the study medicine is safe and effective.