Gem+Nab-P+LEN+TIS for Advanced Unresectable BTC (GALENT-BT)

The goal of this clinical trial is to evaluate the efficacy and safety of combining Gemcitabine, nab-Paclitaxel, Lenvatinib, and Tislelizumab in adults aged 18-75 years with advanced unresectable biliary tract malignancies (including gallbladder cancer, intrahepatic cholangiocarcinoma, and extrahepatic cholangiocarcinoma). The main questions it aims to answer are: What is the objective response rate (ORR) of this quadruplet regimen as first-line therapy? What are the secondary outcomes, including disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety profile? This is a single-arm, open-label, phase II study with no comparison group. Participants will: Receive Gemcitabine (1000 mg/m² IV on Days 1 and 8) and nab-Paclitaxel (125 mg/m² IV on Days 1 and 8) every 3 weeks. Take Lenvatinib (4-8 mg orally daily on Days 1-21). Receive Tislelizumab (200 mg IV on Day 1) every 3 weeks. Undergo 6-8 treatment cycles (adjusted for tolerability) with regular imaging, laboratory tests, and safety assessments. Be followed for 3 years to monitor survival and long-term outcomes. The study plans to enroll 29 participants and will be conducted at a single center over 36 months.