IO Combined With AI as First-line Treatment for Patients With Soft Tissue Sarcoma(TAIS)

Inclusion Criteria:

• Age 18 to 75 years, regardless of gender;

• Patients with histopathologically confirmed undifferentiated sarcoma (except smallround cell undifferentiated sarcoma), synovial sarcoma, angiosarcoma, fibrosarcoma,smooth muscle sarcoma, liposarcoma (except highly differentiated liposarcoma),pleomorphic rhabdomyosarcoma, malignant peripheral nerve sheath meningiomas,connective tissue-promoting proliferative small round cell tumors, nondifferentiablesarcoma (NOS), and sarcoma after radiation therapy

• Patients with locally advanced disease that is not amenable to surgery/radiationtherapy or with recurrent/metastatic disease;

• Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 0 to 1;

• Expected survival of more than 3 months;

• Within 7 days prior to screening (including day 7), laboratory test datarequirements: neutrophil count ≥1.5×10⁹/L, platelet count ≥90×10⁹/L, hemoglobin ≥90g/L (no blood transfusion within 14 days), serum total bilirubin ≤1.5 times theupper limit of normal (ULN); ALT and AST ≤2.5× ULN (≤5× ULN for patients with livermetastases); serum creatinine ≤1.5× ULN or creatinine clearance rate ≥50ml/min;

• Presence of measurable lesions according to RECIST 1.1 criteria;

• The subject (or their legal representative/guardian) must sign an informed consentform, indicating that they understand the purpose of this study, are aware of thenecessary procedures, and are willing to participate in this study.

Exclusion Criteria:

Any of the following conditions will result in exclusion from the study:

• Previous treatment for advanced soft tissue sarcoma, except for those who relapsedmore than six months after adjuvant therapy with a cumulative dose of doxorubicin ≤300mg/m2;

• Received any experimental or anti - tumor drugs within 4 weeks prior to enrollment;

• Previously received any anti - PD - 1, anti - PD - L1, anti - PD - L2, anti - CD137,or anti - CTLA - 4 antibody treatment, or any other antibodies or drugs specificallytargeting T - cell co - stimulation or checkpoint pathways;

• History of other tumors within the past five years, except for cured cervical canceror skin basal cell carcinoma; for patients with post - radiation sarcoma, anotherprimary tumor must have no recurrence or metastasis;

• Symptomatic brain or meningeal metastasis (unless the patient has been treated formore than 6 months, with negative imaging results within 4 weeks prior toenrollment, and stable tumor - related clinical symptoms at the time of enrollment);

• Clinically significant active bleeding;

• Pregnant or lactating women; women of childbearing potential who have not takenadequate contraceptive measures;

• Alcohol abuse or drug addiction;

• Patients with active autoimmune diseases or a history of such diseases that mayrecur (e.g., systemic lupus erythematosus, rheumatoid arthritis, inflammatory boweldisease, autoimmune thyroid disease, multiple sclerosis, vasculitis,glomerulonephritis, etc.), or those at high risk (such as patients who haveundergone organ transplantation and require immunosuppressive therapy). Autoimmunehypothyroidism requiring only hormone replacement therapy or skin diseases notrequiring systemic treatment are excluded;

• Patients who need to receive systemic corticosteroids (equivalent to >10mgprednisone/day) within 14 days prior to enrollment or during the study, or those whorequire other immunosuppressive drug treatment. The use of topical or inhaledcorticosteroids, or short - term (≤7 days) use of corticosteroids for prevention ortreatment of non - autoimmune, non - frequent allergic diseases is excluded;

• Failure of important organs or other severe diseases, including interstitialpneumonia, clinically significant coronary artery disease, cardiovascular disease,or myocardial infarction, congestive heart failure, unstable angina, symptomaticpericardial effusion, or unstable arrhythmia within 6 months prior to enrollment;

• History of human immunodeficiency virus infection, or other acquired or congenitalimmune deficiency diseases, or history of organ transplantation or stem celltransplantation;

• Patients with active chronic hepatitis B or active hepatitis C. HBV carriers, thosewith stable hepatitis B after drug treatment (DNA titer ≤10^3 copies/ml), and thosewith cured hepatitis C (HCV RNA negative) are eligible for enrollment;

• Severe neurological or psychiatric history; severe infection; active disseminatedintravascular coagulation, or other concomitant diseases that, in the opinion of theinvestigator, seriously endanger the safety of the patient or affect the patient'sability to complete the study.