Inclusion Criteria:
- Sign the informed consent form
- Locally advanced or metastatic histologically confirmed transitional cell carcinoma of the urothelium, including the bladder, urethra, ureter, or renal pelvis
- 18 years and older
- HER2 expression (3+ or 2+) as determined by immunohistochemistry or gene amplification by fluorescent in situ hybridization
- Relapsed from or failed at least one prior standard systemic chemotherapy regimen, including immunotherapy, HER2 ADC durgs, and chemothearpy containing cisplatin, carboplatin, paclitaxel, docetaxel, or gemcitabine
- At least 1 measurable lesion could be evaluated by RECIST v1.1
- Performance status: ECOG 0-1
- Life expectancy more than 12 weeks
- Ejection fraction at least 50% (or lower limit of normal) by echocardiogram
- Good organ function:
Blood routine: hemoglobin ≥80g/L, neutrophil ≥1.5×10^9/L, platelet ≥75×10^9/L; Renal function: creatinine≤1.5×upper limit of normal (UNL) or creatinine clearance ≥50ml/min; Liver function: total bilirubin (TBIL)≤1.5×upper limit of normal (UNL); ALT≤2.5×UNL, AST≤2.5×UNL, ALT≤5×UNL and AST≤5×UNL for patients with liver metastasis
Exclusion Criteria:
- Have received trastuzumab or pyrotinib treatment in the past
- Known to have allergic reactions to any ingredients or excipients of experimental drugs
- Radiotherapy, RFA, interventional therapy or surgery were performed within 28 days before the first medication (except for previous diagnostic biopsy)
- Other active malignant tumors, excluding those who have been disease free for more than 5 years or in situ cancer considered to have been cured by adequate treatment
- Clinically significant ascites
- Brain metastasis or meningeal metastasis with neurological symptoms
- Diabetes was not controlled, defined as HbA1c > 7.5% after anti-diabetic drugs or hypertension was not controlled, defined as systolic / diastolic blood pressure > 140 / 90 mmHg after antihypertensive drug
- Myocardial infarction, severe/unstable angina, New York Heart Association (NYHA) class III or IV congestive heart failure in the past 12 months
- Known to be infected with human immunodeficiency virus (HIV), have acquired immunodeficiency syndrome (AIDS) related diseases, have active hepatitis B or hepatitis C
- Pregnant or nursing
- May increase the risk associated with participation in the study or administration of the study drug or mental illness that may interfere with the interpretation of research results
- There are other serious diseases that the researchers believe patients cannot be included in the study