Biomarker-Enriched Kidney-Preserving Strategy With Disitamab Vedotin Plus Tislelizumab in HER2-Positive High-Risk Upper Tract Urothelial Carcinoma

This is a prospective, multicentre, single-arm phase II study evaluating a response-adapted kidney-preserving strategy in patients with HER2-positive high-risk upper tract urothelial carcinoma (UTUC). Patients will receive neoadjuvant disitamab vedotin plus tislelizumab, followed by response-adapted local treatment, including kidney-sparing surgery or radical nephroureterectomy based on predefined criteria. The primary objective is to assess whether this multimodal strategy can achieve clinically meaningful oncologic control while preserving renal function, as measured by 1-year kidney-intact event-free survival (KI-EFS). Secondary and exploratory objectives include evaluation of clinical response, survival outcomes, safety, renal function preservation, and longitudinal dynamics of circulating and urinary tumor DNA.