Neoadjuvant Gemcitabine Plus Trastuzumab Rezetecan in HER2-positive UTUC

Upper tract urothelial carcinoma (UTUC) carries a poor prognosis, with conventional GC (gemcitabine plus cisplatin) regimens achieving only a 19% pathological complete response (pCR) rate in the neoadjuvant setting. Antibody-drug conjugates (ADCs) have shown promising results in advanced urothelial carcinoma, Meanwhile the clinical application of traditional cisplatin-based chemotherapy is associated with significant limitations. Therefore, exploring the efficacy and safety of Trastuzumab Rezetecan (an anti-HER2 ADC) combined with gemcitabine in UTUC is of considerable importance. This trial will enroll patients with HER2 2-3+ UTUC. After pathological diagnosis, patients will receive intravenous infusions of gemcitabine and Trastuzumab Rezetecan. The treatment regimen consists of a 21-day cycle: 4 cycles of neoadjuvant therapy, followed by 2 cycles of adjuvant therapy for patients who do not achieve pCR (total of 6 cycles). For patients with suboptimal pathological downstaging after surgery (≥ypT3 or ypN+), combination with immune checkpoint inhibitors (ICIs) is recommended. During the neoadjuvant period, adverse events will be closely monitored. Regular imaging and follow-up assessments will be performed, and events such as disease recurrence, progression, and their corresponding time points will be documented. The primary endpoint is pCR rate. Secondary endpoints include adverse events during the neoadjuvant period, event-free survival (EFS), overall survival (OS).