Perioperative Pembrolizumab (MK-3475) Plus Cystectomy or Perioperative Pembrolizumab Plus Enfortumab Vedotin Plus Cystectomy Versus Cystectomy Alone in Participants Who Are Cisplatin-ineligible or Decline Cisplatin With Muscle-invasive Bladder Cancer (MK-3475-905/KEYNOTE-905/EV-303)

Inclusion Criteria: * Have a histologically confirmed diagnosis of urothelial carcinoma/muscle-invasive bladder cancer \[MIBC\] (cT2-T4aN0M0 or T1-T4aN1M0) with predominant (≥50%) urothelial histology to be confirmed by Blinded Independent Central Review (BICR) (central pathology and/or imaging). * Clinically nonmetastatic bladder cancer determined by imaging * Eligible for radical cystectomy (RC) + pelvic lymph node dissection (PLND), and agreement to undergo curative intent standard RC + PLND (including prostatectomy if applicable) * Ineligible for treatment with cisplatin, as defined by meeting at least one of the following criteria OR be eligible for treatment with cisplatin but decline treatment with cisplatin-based chemotherapy: * Impaired renal function with measured or calculated creatinine clearance (CrCl) 30 to 59 mL/min (calculated by Cockcroft-Gault method, Modification of Diet of Renal Disease \[MDRD\] equations, or measured by 24-hour urine collection) * Eastern Cooperative Oncology Group (ECOG) Performance Status 2 * Common Terminology Criteria for Adverse Events (CTCAE) v.4 Grade ≥2 audiometric hearing loss * New York Heart Association (NYHA) Class III heart failure * Transurethral resection (TUR) of a bladder tumor that is submitted for central pathology assessment and adequate to determine urothelial histology and PD-L1 expression assessment * ECOG performance status of 0, 1, or 2 * Adequate organ function * A male participant is eligible to partic…