Evaluation of the Efficacy of Anti-HER2 Antibody-Drug Conjugates (ADC) in Locally Advanced or Metastatic Bladder Cancer Based on Organoid Technology.

Inclusion Criteria: * 1\. Age 18-80 years, any gender; 2. All bladder cancer patients to be included in the study must meet the inclusion criteria in item 3 regarding staging, and tumor biopsy tissue taken before ADC treatment will be used for organoid culture; 3. Patients with unresectable locally advanced (cT4b and/or N2-3) or metastatic bladder cancer (M1) who have failed platinum-based chemotherapy; 4. Patients who have shown disease progression after at least one round of platinum-based chemotherapy, or have no satisfactory alternative treatment options; 5. Patients who can tolerate adverse reactions from ADC drug enfortumab vedotin treatment; 6. ECOG performance status score of 0-2; 7. Judged by the investigator to be able to comply with the trial protocol, have good adherence, cooperate in monitoring adverse events and efficacy, and participate in follow-up; 8. Voluntarily participate in this clinical trial, understand the study procedures, and have signed the informed consent form for participation. Exclusion Criteria: * 1\. Patients with locally advanced or metastatic bladder cancer who have not previously received platinum-containing chemotherapy; 2. Individuals with immunodeficiency or impairment (e.g., patients with AIDS, or those using immunosuppressants or undergoing radiotherapy); 3. Participants known to be allergic to the investigational drug, similar drugs, or excipients, or those with allergic constitution; 4. Individuals on long-term steroid medication or with a history of drug abuse or dependence; 5. Those who are planning to become pregnant, are currently pregnant, or are breastfeeding; 6. Individuals with abnormal blood routine, liver and kidney function, or coagulation indicators (considered abnormal if one or more of the following are met): 1. Absolute neutrophil count (ANC) ≤ 1.5 × 10⁹/L; 2. White blood cell count (WBC) ≤ 3.0 × 10⁹/L; 3. Platelet count (PLT) ≤ 90 × 10⁹/L; 4. Hemoglobin (HB) ≤ 90 g/L; 5. Total bilirubin (TBIL) ≥ 1.5 × the upper limit of normal (ULN) of the institution; 6. Estimated glomerular filtration rate (eGFR) ≤ 30 ml/min/1.73m²; 7. International normalized ratio (INR) and activated partial thromboplastin time (APTT) ≥ ULN (except for patients receiving anticoagulant therapy, if considered clinically acceptable by the investigator); 7. Participants with other factors that may cause the study to be prematurely terminated, including: <!-- --> 1. History or current diagnosis of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML); 2. History of clear neurological or psychiatric disorders, including epilepsy or dementia; 3. Severe comorbidities that endanger patient safety or affect study completion (e.g., severe hypertension, diabetes, thyroid disorders); 4. Other serious diseases requiring concomitant treatment, with severe laboratory abnormalities; 5. Other serious diseases accompanied by family or social factors that could impact participant safety, or the collection of data and samples; 6. Uncontrolled comorbid conditions, including but not limited to persistent or active infections requiring treatment, symptomatic congestive heart failure, unstable angina, or arrhythmias; 8. Participants deemed unsuitable for this study by the investigator.