Cadonilimab in the Treatment of Advanced Soft Tissue Sarcoma

Inclusion Criteria: * 1\. Written and signed informed consent. * 2\. Male or female, age≥ 18 and ≤ 70 years old on day of signing informed consent. * 3\. Pathologically confirmed unresectable or metastatic soft tissue sarcoma, mainly including Undifferentiated pleomorphic sarcoma/malignant fiber histiocytoma, Alveolar soft part sarcoma, dedifferentiated liposarcoma, fibrosarcoma, Leiomyosarcoma, Anigosarcoma, Synovial sarcoma. * 4\. Patients who have failed at least one chemotherapy (including anthracyclines) in the last 6 months (excluding acinar soft tissue sarcoma). Exclusion Criteria: * 1\. Prior use of investigational products or devices within 4 weeks prior to the first administration of the study treatment. * 2\. Concurrent enrollment into another clinical study, except the study belongs to investigational, non-interventional studies or the follow-up period of interventional studies. * 3\. Prior exposure to any experimental antitumor vaccines, or any agent targeting T-cell costimulation or immune checkpoint pathways (eg, anti-PD-1, anti-PD-L1, anti-CTLA-4, anti-CD137 or anti-OX40 antibody, etc). * 4\. Active autoimmune diseases; * 5\. History of transplantation; * 6\. Known history of primary immunodeficiency virus infection or known history of testing positive for human immunodeficiency virus (HIV).