Vedotin for Injection in Second-line or Later Treatment of Advanced Biliary Tract Cancer

Prior treatment

• Prior treatment with MMAE-payload antibody-drug conjugates (ADCs).
• Planned or prior organ or bone marrow transplantation.
• Administration of live vaccines within 30 days before the first study drug dose. Inactivated seasonal injectable influenza vaccine is permitted.
• Receipt of radiotherapy, chemotherapy, targeted therapy or immunotherapy within 4 weeks prior to enrollment.
• Participation in another interventional drug clinical trial within 4 weeks prior to enrollment.

Other illness

• Diagnosis of other malignant tumors within the past 5 years, except for carcinoma in situ and basal cell carcinoma.
• Known central nervous system metastases (excluding patients with stable, asymptomatic disease 4 weeks after radiotherapy or surgery), or evidence of carcinomatous meningitis.
• Psychiatric or neurological disorders that may impair subject compliance with study requirements.
• Uncontrolled clinically significant cardiac signs or diseases.
• Active infection or fever (excluding documented tumor-related fever).
• History or evidence of interstitial lung disease or active non-infectious pneumonitis.
• Other medical conditions rendering the subject ineligible for enrollment, including immunodeficiency, active pulmonary tuberculosis, positive hepatitis C virus test, uncorrectable electrolyte disturbances, uncontrolled pericardial, pleural or peritoneal effusion. Patients with hepatitis B may be enrolled if HBV-DNA \< 500 IU/mL and liver function is normal after treatment.
• Known hypersensitivity to any study drug or its excipients.

Other

• Pregnant or lactating women.
• Subjects deemed inappropriate for enrollment at the investigator's discretion.

• Aged 18-80 years, of any gender.
• Patients with histologically or cytologically confirmed primary advanced biliary tract carcinoma (BTC), including intrahepatic cholangiocarcinoma (ICC), extrahepatic cholangiocarcinoma (ECC), gallbladder carcinoma (GBC), and recurrent biliary tract carcinoma.
• EGFR IHC-positive assessed by a pathological laboratory.
• Have received at least one line of prior systemic therapy.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• Expected survival ≥ 3 months.
• At least one measurable target lesion assessable by CT or MRI according to RECIST version 1.1.
• Laboratory test results meeting the following criteria:
  • (1) Hematologic function: Hemoglobin (Hb) ≥90 g/L; white blood cell count (WBC) ≥ lower limit of normal (LLN); absolute neutrophil count (ANC) ≥1.5×10⁹/L; platelet count ≥100×10⁹/L.
  • (2) Renal function: Creatinine ≤1.5 × upper limit of normal (ULN); creatinine clearance (Ccr) ≥55 mL/min.
  • (3) Hepatic function: Total bilirubin ≤1.5 × ULN; ALT and AST ≤2.5 × ULN. (For patients with intrahepatic cholangiocarcinoma or liver metastases: total bilirubin ≤3 × ULN; ALT and AST ≤5 × ULN).
  • 9\. Absence of severe complications, such as active gastrointestinal hemorrhage, perforation, jaundice, gastrointestinal obstruction, or non-neoplastic fever \>38 °C.
  • 10\. Women of child-bearing potential: agree to use contraception during the study and for 6 months after the last study treatment; have a negative serum or urine pregnancy test within 7 days prior to enrollment; and are not lactating. Male patients: agree to use contraception during the study and for 6 months after the last study treatment.
  • 11\. Expected good compliance and ability to follow study procedures for efficacy and safety follow-up.
  • 12\. Able to understand the study and provide written informed consent voluntarily.