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: * Participants must have the capacity to participate/enroll in the study and to provide informed consent * Histologically confirmed muscle-invasive UC (also termed transitional cell carcinoma \[TCC\]) of the bladder or upper urinary tract * Tumor-node-metastasis (TNM ) classification (Union for International Cancer Control \[UICC\]/American Joint Committee on Cancer \[AJCC\] 7th edition) at pathological examination of surgical resection specimen of (y)pT3-4 or (y)pN+ and M0 * Surgical resection of MIUC of the bladder or upper tract * Participants who have received neoadjuvant chemotherapy (NAC), including antibody drug-conjugate, either alone or in combination with a checkpoint inhibitor (CPI), are eligible * Participants who have not received any prior NAC are also eligible, provided they meet one of the following criteria, which would make them ineligible to receive adjuvant cisplatin-based therapy: participant 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 negative baseline computed tomography (CT) or magnetic resonance imaging (MRI) scan of the pelvis, abdomen, and chest no more than 28 days prior to randomization * Full recovery from cystectomy or nephroureterectomy within 120 days following surgery * Eastern cooperative oncology group (ECOG) performance status of 0 or 1 * Negative human immunodeficiency virus (…