A Phase 3 Study Comparing Carelizumab Plus Nab-paclitaxel and Apatinib, Carelizumab Plus Nab-paclitaxel, and Nab-paclitaxel in Patients With Advanced Triple Negative Breast Cancer.

Inclusion Criteria: * ECOG Performance Status of 0-1. * Expected lifetime of not less than three months * Metastatic or locally advanced, histologically documented TNBC (absence of HER2, ER, and PR expression) * Cancer stage: locally advanced or metastatic breast cancer; Locally advanced breast cancer not amenable to radical resection. * No prior systemic antitumor therapy for metastatic triple-negative breast cancer. * Adequate hematologic and organ function * Measurable disease according to Response Evaluation Criteria in Solid Tumors v1.1 (RECIST v1.1) Exclusion Criteria: * Known central nervous system (CNS) disease. * Previously received anti-VEGFR small molecule tyrosine kinase inhibitors or anti-PD-1/PD-L1 antibody. * A history of bleeding, any serious bleeding events. * Uncontrolled pleural effusion, pericardial effusion. * Malignancies other than TNBC within 5 years prior to randomisation, or ascites requiring recurrent drainage procedures * History of interstitial pneumonitis. * Severe chronic or active infections in need of systemic antibacterial, antifungal, or antiviral treatment, including TB, etc. * Prior allogeneic stem cell or solid organ transplantation. * History of autoimmune disease * Active hepatitis B or hepatitis C * Pregnancy or lactation. * Peripheral neuropathy grade ≥2. * Participants with poor blood pressure control; * Myocardial infarction incident within 6 months prior to randomisation; * Treatment with systemic immunostimulatory agents within 4 weeks prior to randomisation * Treatment with systemic immunosuppressive medications within 2 weeks prior to randomisation