RecruitingPhase 2ProcedureAlternating HAIC and Systemic Chemotherapy With or Without Adebrelimab and Apatinib for Unresectable Biliary Tract CancerThis prospective real-world study aims to evaluate the effectiveness and safety of an alternating treatment regimen combining hepatic arterial infusion chemotherapy (HAIC) with systemic chemotherapy, with or without adebrelimab and apatinib, in patients with unresectable biliary tract cancer receiving first-line treatment. The study comprises two cohorts: one receiving alternating HAIC and systemic chemotherapy alongside adebrelimab and apatinib, and the other receiving alternating HAIC and systemic chemotherapy alone. Treatment allocation follows real-world clinical decision-making. Patients will be monitored throughout the treatment period to assess tumor response, survival outcomes, and safety profiles. The study aims to generate evidence on the clinical benefits of integrating immunotherapy and targeted therapy into HAIC-based regimens for this patient population.