A Clinical Study of SHR-A1811 in the Treatment of HER2-positive Locally Advanced or Metastatic Biliary Tract Cancer

Inclusion Criteria: 1. Age 18-75 years old (including both ends), male or female; 2. ECOG-PS score: 0 or 1; 3. Expected survival ≥ 12 weeks; 4. Locally advanced or metastatic biliary tract cancer confirmed by histopathology or cytology; 5. Subjects who had not previously received any systemic antitumor therapy were allowed to have previously received radical therapy, and had received the last dose of radical therapy for at least 6 months until disease recurrence; 6. According to the RECIST v1.1 standard, the subjects had at least one measurable lesion; 7. The main organ function is normal, in line with the program requirements; 8. Consent to contraception. Exclusion Criteria: 1. Other active malignancies within 5 years or at the same time; 2. Local antitumor therapy was received within 4 weeks prior to initiation of treatment; 3. Subjects with biliary obstruction should be excluded; 4. There is active autoimmune disease or a history of autoimmune disease that may recur; 5. Known or suspected history of interstitial pneumonia or interstitial lung disease, or prior history of interstitial pneumonia or interstitial lung disease requiring hormone therapy; 6. Severe infection within 4 weeks prior to initiation of study treatment; 7. Active hepatitis B virus (HBV) infection; 8. Have serious cardiovascular and cerebrovascular diseases.