TST001 in Patients With CLDN18.2 Positive Previously Treated Advanced Biliary Tract Cancer

Inclusion Criteria: * Histologically confirmed, unresectable advanced or metastatic biliary tract cancer. * Patients failed at least one prior line of systemic medications; if patients had disease progression during or within 6 months after the completion of adjuvant therapy or neoadjuvant therapy, the adjuvant therapy or neoadjuvant therapy could be regarded as one line of therapy. * CLDN18.2 expression positive confirmed through tumor tissue. * Patients with at least one measurable disease according to RECISTv1.1. * ECOG PS of 0 or 1. * Patients have predicted life expectancy ≥ 12 weeks. * Paitients with adequate cardica, liver, renal function, etc. Exclusion Criteria: * • History of another concurrent primary malignancy. * Untreated or symptomatic CNS metastases. * Prior treatment targeting CLDN18.2. * Major surgical procedure, prior locoregional therapy such as radioembolization within 28 days prior to the first dose of study drug. * Prior serious hypersensitivity to monoclonal antibody or any component of the investigational drug. * Patients had any of the following within 6 months prior to first dose of study treatment: cerebrovascular accident, transient ischemic attack, myocardial infarction or unstable angina pectoris, heart failure NYHA III or IV degree, or uncontolled uarrhythmia requiring intervention. * Patients who are pregnant or lactating.