A Study to Evaluate the Efficacy and Safety of Autogene Cevumeran With Nivolumab Versus Nivolumab Alone in Participants With High-Risk Muscle-Invasive Urothelial Carcinoma (MIUC)

Inclusion Criteria:

• Histologically confirmed muscle-invasive UC (also termed TCC) of the bladder orupper urinary tract

• TNM classification (UICC/AJCC 7th edition) at pathological examination of surgicalresection specimen of (y)pT3-4 or (y)pN+ and M0

• Surgical resection of MIUC of the bladder or upper tract

• Participants who have not received prior neoadjuvant cisplatin chemotherapy (NAC)must be ineligible to receive adjuvant cisplatin therapy due to patient refusal,cisplatin ineligibility or investigator decision

• Tumor tissue must be provided for biomarker analysis

• Absence of residual disease and absence of metastasis, as confirmed by a negativebaseline Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scan of thepelvis, abdomen, and chest no more than 28 days prior to randomization.

• Full recovery from cystectomy or nephroureterectomy within 120 days followingsurgery

• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

• Negative HIV test at screening

• No evidence of active hepatitis B, defined as having a negative hepatitis B surfaceantigen (HbsAg) test at screening

• Negative hepatitis C virus (HCV) antibody test at screening, or a positive HCVantibody test followed by a negative HCV RNA test at screening

Exclusion Criteria:

• Partial cystectomy in the setting of bladder cancer primary tumor or partialnephroureterectomy in the setting of renal pelvis primary tumor

• Any approved anti-cancer therapy, including chemotherapy, or hormonal therapy within 3 weeks prior to initiation of study treatment

• Any prior neoadjuvant immunotherapy

• Adjuvant chemotherapy or radiation therapy for UC following surgical resection

• Malignancies other than UC within 5 years prior to randomization

• Treatment with a live, attenuated vaccine within 4 weeks prior to initiation ofstudy treatment