Clinical Research Directory

Inclusion Criteria * Has histologically confirmed very-high-risk non-muscle-invasive urothelial carcinoma of the bladder. * Has transurethrally unresectable bladder tumor, defined as visually incomplete TURBT and/or extensive high-volume disease considered unsuitable for complete and oncologically adequate transurethral resection. * Has undergone cystoscopy and TURBT evaluation before study enrollment. * Has received systemic PD-1/PD-L1 inhibitor-based bladder-sparing therapy before randomization. * Has achieved tumor-free status before randomization, defined as: 1. No visible bladder tumor on cystoscopy; 2. Negative bladder biopsy and/or TURBT pathology; 3. Negative urine cytology; 4. Negative urinary tumor DNA (utDNA); 5. No radiographic evidence of progression or metastasis. * Has Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2. * Has adequate organ function. * Has provided written informed consent. Cohort A Only * Achieved tumor-free status at the initial response evaluation after induction systemic therapy. * Maintained tumor-free status after additional systemic therapy before randomization. Cohort B Only * Did not achieve tumor-free status at the initial response evaluation because of residual non-muscle-invasive disease. * Subsequently underwent complete TURBT/resection of residual disease followed by additional systemic therapy. * Achieved tumor-free status at the second response evaluation before randomization. Exclusion Criteria * Has muscle-invasive bladder cancer (≥T2), locally advanced unresectable disease, nodal disease, or distant metastasis. * Has concurrent upper tract urothelial carcinoma. * Has persistent visible tumor, positive bladder pathology, positive urine cytology, or positive utDNA before randomization. * Has received prior systemic immunotherapy for metastatic urothelial carcinoma. * Has active autoimmune disease requiring systemic treatment. * Is receiving systemic immunosuppressive therapy. * Has uncontrolled infection requiring systemic therapy. * Has another active malignancy requiring systemic treatment. * Has known active hepatitis B, hepatitis C, human immunodeficiency virus infection, or active tuberculosis. * Has pregnancy or breastfeeding. * Has any medical or psychiatric condition that, in the investigator's judgment, would interfere with study participation or interpretation of results.