New drug duo aims to fight kidney cancer without losing the kidney

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age ≥18 years at the time of informed consent. * Histologically confirmed upper tract urothelial carcinoma (UTUC) arising from the renal pelvis or ureter, based on ureteroscopic biopsy. * High-risk UTUC, defined by at least one of the following features: Tumour size ≥2 cm; High-grade cytology or biopsy; Radiographic evidence of local invasion (≥cT2); Hydronephrosis; Multifocal disease * Clinical stage cT1-T3, N0-N1, M0, based on radiographic assessment. * N1 disease is permitted only if lymph nodes are considered resectable. * HER2-positive disease, defined as immunohistochemistry (IHC) score of 1+，2+ or 3+ on tumour tissue, assessed according to predefined criteria. * At least one measurable lesion according to RECIST version 1.1. * ECOG performance status of 0-1 * Adequate organ function, including: Hematologic function; Hepatic function; Renal function (no strict upper/lower limit required); * Patients must be considered potential candidates for a kidney-preserving treatment strategy, including: Absolute or relative indication for renal preservation (e.g., solitary kidney, baseline renal insufficiency), or Strong preference for kidney preservation after multidisciplinary discussion * Ability to understand and willingness to sign written informed consent. Exclusion Criteria: * Evidence of distant metastatic disease (M1). * Unresectable or bulky nodal disease (≥N2) not amenable to curative-intent surgery. * Prior systemic therapy for urothelial carcinoma, including:Chemotherapy; Immunotherapy; HER2-targeted therapy. * Prior radical nephroureterectomy for current disease. * Active autoimmune disease requiring systemic treatment within the past 2 years. * Current use of immunosuppressive medication, excluding physiologic doses of corticosteroids. * Uncontrolled intercurrent illness, including but not limited to: Active infection requiring systemic therapy; Uncontrolled cardiovascular disease; Significant pulmonary disease * Known active hepatitis B, hepatitis C, or HIV infection with uncontrolled viral replication. * History of another malignancy within the past 5 years, except: Adequately treated basal cell carcinoma; Squamous cell skin cancer; In situ carcinoma. * Pregnant or breastfeeding women. * Any condition that, in the opinion of the investigator, would interfere with study participation or interpretation of results.