Combination of Gemcitabine, Albumin-paclitaxel , Sintilimab and Bevacizumab in Unresectable Gallbladder Cancer

Study design: Prospective, single-arm, single-center phase II clinical study; Primary endpoint: Objective response rate via investigator, Safety; Secondary endpoints: disease control rate, disease-free survival, overall survival, and proportion of acceptable radical resection of primary lesions; Main characteristics of enrolled patients: Patients with initially unresectable gallbladder cancer; Interventions: Combination of Gemcitabine, Nab-paclitaxel, Sintilimab and Bevacizumab; Sample size: Using Simon's two-stage design, 15 patients in the first stage, and if more than 4pts response, enlarge the sample size to 45 patients in total; Treatment until: 1. successfully conversed to resectable disease 2. progressed disease 3. intolerable toxicity 4. patient requests withdrawal; Research process: In this study, patients who met the inclusion criteria were evaluated at the end of every 9 weeks of treatment, up to surgical treatment or disease progression; Safety evaluation: Evaluate adverse reactions according to CTCAE 5.0; Follow up: every 90 days (±7 days) until the subject died, lost follow-up or the end of the study.