Neoadjuvant Disitamab Vedotin, Toripalimab, and Radiotherapy for High-risk UTUC ( LUXUS07.1 )

This is an open-label, single-arm, single-cohort, prospective clinical study evaluating neoadjuvant antibody-drug conjugate therapy combined with immunotherapy and sequential radiotherapy followed by radical surgery in patients with high-risk upper tract urothelial carcinoma (UTUC). Eligible patients will receive neoadjuvant disitamab vedotin (RC48) plus toripalimab, followed by response-guided neoadjuvant radiotherapy and radical nephroureterectomy with bladder cuff excision. The study will assess the safety, feasibility, and preliminary antitumor activity of this multimodal neoadjuvant strategy, with pathological complete response rate as the primary endpoint.

Inclusion Criteria: * Age ≥18 years, male or female. * Imaging evaluation before treatment excludes distant organ metastasis or other concurrent malignancy and suggests resectable high-risk UTUC. * Completed pathological biopsy with a clear pathological diagnosis : including puncture biopsy, ureteroscopy and urine cytology, at least one of which is clearly diagnosed as uroepithelial carcinoma, which may include no more than 50% or more proportion of squamous, adenoid, sarcomatoid differentiation and other special differentiation types; * High-risk features, including muscle-invasive disease, high-grade tumor, multifocal disease, tumor diameter ≥2 cm, hydronephrosis, or regional lymph node involvement. * HER2 expression by immunohistochemistry 1+ to 3+; PD-L1 expression not restricted. * Have the willingness to undergo radical surgical treatment and perioperative adjuvant treatment, have good compliance, and be able to co-operate with the treatment and follow-up plan specified by the clinician; * Postoperative life expectancy of at least 6 months; ECOG score ≤ 2. Exclusion Criteria: * Distant metastases or other malignant neoplastic diseases combined with other malignant neoplasms in the same period had been detected at the time of surgery, or the present was a progression after palliative resection of previous epithelial carcinoma of the urothelium; * History of pelvic and abdominal radiotherapy; history of inflammatory bowel disease; history of systemic chemotherapy; * Pregnant women or breastfeeding women; or women of childbearing potential who are not using reliable contraception; * The presence of active infections in those with pre-existing or coexisting haemorrhagic disorders * clinically significant cardiac disease (e.g., hypertension controlled with medications, unstable angina, New York Heart Association (NYHA) class ≥II congestive heart failure, unstable symptomatic arrhythmias, or class ≥II peripheral vascular disease); * Psychological, familial, and social factors leading to lack of informed consent.