Bladder Cancer Clinical Trials

• Willing to participate, able to provide written informed consent, and able to understand and comply with study requirements and the assessment schedule.

• Age 18 to 85 years on the date of informed consent.

• Residual disease after TURBT; histologically confirmed urothelial carcinoma of the bladder staged cT2-T4aN0-1M0 per AJCC 8th edition by histology and imaging. For mixed histology, urothelial carcinoma must be predominant (≥50%).

• Availability of TURBT tumor tissue and corresponding pathology report; either fresh surgical tissue or unstained slides may be submitted.

• HER2-positive: IHC 2+ or 3+.

• No prior anti-HER2-directed therapy (including but not limited to HER2 antibodies, HER2-targeting ADCs, or HER2-targeted TKIs) and no prior PD-(L)1 therapy.

• ECOG performance status 0-2.

• Adequate organ function based on screening labs obtained ≤14 days before enrollment:

• a. For the following counts, no growth-factor support within 14 days prior to sample collection: i. Absolute neutrophil count ≥ 1.5 × 10\^9/L ii. Platelets ≥ 100 × 10\^9/L iii. Hemoglobin ≥ 90 g/L b. INR or aPTT ≤ 1.5 × upper limit of normal (ULN) c. Total bilirubin ≤ 1.5 × ULN (≤ 3 × ULN for Gilbert syndrome or isolated indirect hyperbilirubinemia) d. AST, ALT, and alkaline phosphatase ≤ 2.5 × ULN

• Women of childbearing potential must have a negative urine or serum pregnancy test within ≤7 days before enrollment and agree to use highly effective contraception during the study and for ≥120 days after the last dose of zanidatamab, tislelizumab, or chemotherapy (whichever occurs later).

⁃ Non-sterilized men must agree to use highly effective contraception during the study and for ≥120 days after the last dose of zanidatamab, tislelizumab, or chemotherapy (whichever occurs later).