Stage II-IIIa Urothelial Cancer Randomizing Pre-operative Nivolumab With or Without Relatlimab

Inclusion Criteria: * Willing and able to provide informed consent * Age ≥ 18 years * Resectable muscle-invasive UC of the bladder, defined as cT2-4aN0M0 OR cT1-4aN1M0. In cT1N1 patients, lymph node positivity would need to be cytologically or histologically confirmed. * Surgical resection (cystectomy) is the advised locoregional treatment and is accepted by the subject after consultation with the urologist. * Patients are either cisplatin ineligible or elect to not undergo cisplatin based neoadjuvant chemotherapy after a balanced discussion of risks and benefits with the treating physician. Cisplatin eligibility is determined based on the Galsky criteria * World Health Organization (WHO) performance Status 0 or 1. * Urothelial cancer is the dominant histology (\>50%). Any component of small cell or adenocarcinoma is not allowed. * Formalin-fixed paraffin-embedded (FFPE) tumor specimens in paraffin blocks from diagnostic TUR available. * Screening laboratory values must meet the following criteria: WBC ≥ 2.0x109/L, Platelets ≥100 x109/L, Hemoglobin ≥5.5 mmol/L, GFR\>30 ml/min, AST ≤ 1.5 x ULN, ALT ≤1.5 x ULN, Bilirubin ≤1.5 X ULN * Negative pregnancy test (βHCG in blood or urine) within 2 weeks of Day 1 Cycle 1 for female patients of childbearing potential. * Highly effective contraception for female subjects if the risk of conception exists. Female patients of childbearing potential must comply with contraception methods as requested by the study protocol (→ 8.2.1 Pregnancy…