Overview Pembrolizumab (MK-3475) as First-line Therapy for High Risk T1 Non-Muscle-Invasive Bladder Cancer Status: Recruiting Trial end date: 2022-04-01 Target enrollment: Participant gender: Summary The purpose of this study is to find out what effects, good and/or bad, pembrolizumab has on the participant and urothelial cancer. Phase: Phase 2 Details Lead Sponsor: Memorial Sloan Kettering Cancer CenterCollaborator: Merck Sharp & Dohme Corp.Treatments: Pembrolizumab