DV+BCG in HER2-Expressing, BCG-Naïve High-Risk NMIBC

Inclusion Criteria 1. Age ≥ 18 years. 2. Histologically confirmed high-risk, non-muscle-invasive urothelial carcinoma of the bladder (UCC) (with \>50% urothelial carcinoma as the predominant histological component), defined by the presence of any of the following: a. T1 tumor; b. High-grade Ta tumor; c. Carcinoma in situ (CIS). 3. Complete resection of all Ta/T1 papillary lesions (including patients with concomitant CIS). The most recent Transurethral Resection of Bladder Tumor (TURBT) must have been performed within 12 weeks prior to randomization. A second TURBT was required if indicated per current local applicable guidelines. 4. HER2 expression (IHC 1+/2+/3+) as confirmed by immunohistochemistry (IHC) testing at the local institution's pathology department. 5. Unwillingness or ineligibility to undergo radical cystectomy. 6. Eastern Cooperative Oncology Group (ECOG) performance status (PS) of ≤ 2. 7. Signed informed consent form (ICF). Exclusion Criteria 1. Histologically confirmed evidence of muscle-invasive (T2 or higher), locally advanced, or metastatic urothelial carcinoma, or the presence of concurrent extravesical non-muscle-invasive urothelial carcinoma. 2. Histopathological findings of pure small cell carcinoma, pure adenocarcinoma, pure squamous cell carcinoma, or pure squamous CIS of the bladder. 3. History of upper tract urothelial carcinoma (except for cases with no recurrence within 2 years following radical treatment for UTUC). 4. Prior therapy with any other type of HER2-targeted inhibitor. 5. Major surgery within 2 weeks prior to randomization. 6. Any other condition that, in the investigator's judgment, would make the patient unsuitable for participation in this study.