Inclusion Criteria:
* Age ≥12 years old, male or female;
* ECOG PS score 0-2;
* Histopathologically confirmed unresectable locally advanced or metastatic clear cell sarcoma;
* Previous surgery, radiotherapy, or chemotherapy is allowed; patients who have used PD1/PDL1 for 4 months without effect are allowed to continue using the same PD1/PDL1 drug;
* At least 1 measurable lesion according to RECIST1.1 criteria;
* Normal function of major organs, meeting the following criteria within 7 days before treatment:① Hematology examination criteria must be met (without blood transfusion or blood products, and without correction by G-CSF or other hematopoietic stimulating factors within 14 days):a) Hemoglobin (HB) ≥90g/L; b) Absolute neutrophil count (ANC) ≥1.5×10⁹/L; c) Platelets (PLT) ≥100×10⁹/L; ② Biochemical examination must meet the following criteria: a) Total bilirubin (TBIL) ≤1.5× upper limit of normal (ULN); b) Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5×ULN, and if with liver metastasis，ALT and AST ≤5×ULN; c) Serum creatinine (Cr) ≤1.5×ULN or creatinine clearance (CCr) ≥60ml/min; ③ Urine protein \<2+, and 24h urine protein quantitation shows protein ≤1g; ④ Coagulation function: INR \<2.0 and APTT ≤1.5×ULN ⑤ Doppler ultrasound assessment: Left ventricular ejection fraction (LVEF) ≥ lower limit of normal (60%) ⑥ Thyroid function: TSH ≤ upper limit of normal (ULN); if abnormal, T3 and T4 levels should be considered, and subjects can be enrolled if T3 and T4 levels are normal;
* Male or female of childbearing potential agree to use reliable contraception during treatment and for at least 12 months after the last study drug administration.
* Consent to sign the informed consent form, good compliance, and cooperation with follow-up.
Exclusion Criteria:
* Previous treatment with class Ib MET inhibitors or cabozantinib;
* Clear cell sarcoma with only bone lesions and no soft tissue mass formation;
* Receiving other antitumor treatments within 4 weeks before enrollment, including systemic therapy, radiotherapy, major surgery, or participating in other clinical trials;
* Patients who have not recovered from adverse events caused by previous treatments to NCI-CTCAE (5.0) ≤1 grade, excluding alopecia;
* Subjects with significant bleeding risk determined by the investigator, including but not limited to: 1) Imaging shows that the tumor has invaded important blood vessels or the investigator judges that the tumor is very likely to invade important blood vessels during the subsequent study period, causing fatal massive hemorrhage, or with large vein (iliac vein, inferior vena cava, pulmonary vein, superior vena cava) tumor thrombus formation, or a history of aneurysm with possible rupture; 2) Receiving major surgery or having obvious traumatic injury within 4 weeks before enrollment, or any bleeding or bleeding event ≥NCI-CTCAE grade 3, or any unhealed wound, ulcer, or fracture; 3) Hereditary or acquired bleeding and thrombotic tendencies, such as hemophilia, coagulation disorders, thrombocytopenia, hypersplenism, etc.; 4) Coagulation function abnormalities (INR \>1.5 or prothrombin time (PT) \>ULN+4 seconds or APTT \>1.5 ULN), with bleeding tendency, or receiving thrombolytic or anticoagulant therapy; 5) Patients receiving anticoagulants or vitamin K antagonists such as warfarin, heparin, or their analogs;Note: Under the premise that the international normalized ratio (INR) ≤1.5, low-dose heparin (adult daily dose 0.6×10⁴-1.2×10⁴ U) or low-dose aspirin (daily dose ≤100 mg) is allowed for prophylactic purposes;
* Presence of the following diseases or complications: 1) History of hypertension that cannot be well controlled with 1-2 antihypertensive drugs (systolic blood pressure ≥150mmHg or diastolic blood pressure ≥100mmHg); 2) Poorly controlled diabetes (fasting blood glucose \>10mmol/L); 3) Significant cardiovascular damage including but not limited to: unstable angina, myocardial ischemia or infarction, ≥grade 2 congestive heart failure (New York Heart Association (NYHA) classification); history of arterial/venous thromboembolic events within 6 months, such as cerebrovascular accident (including transient ischemic attack), deep vein thrombosis, and pulmonary embolism; 4) Grade I or above sinus bradycardia; or second-degree or above atrioventricular block, or sinus arrest (except with pacemaker); arrhythmia (including QTc ≥480ms); need to take drugs that can prolong QTc. 5) Liver cirrhosis, decompensated liver disease, active hepatitis, or chronic hepatitis requiring antiviral therapy; 6) Urinalysis showing proteinuri≥++, confirmed by 24-hour urine protein quantification \> 1.0 g; 7）Renal failure requiring hemodialysis or peritoneal dialysis; 8）History of immunodeficiency, including HIV positivity or other acquired/congenital immunodeficiency diseases, history of organ transplantation or hematopoietic stem cell transplantation, or receiving systemic corticosteroid therapy or any other form of immunosuppressive therapy within 2 weeks before enrollment;Note: In the absence of active autoimmune diseases, inhaled or topical steroids and adrenal cortical hormones at a dose \> 10 mg/day prednisone equivalent are allowed, adrenal cortical hormone replacement therapy with a dose not exceeding 10 mg/day prednisone equivalent is allowed, and glucocorticoids are allowed as prophylactic agents for hypersensitivity reactions (such as prophylaxis before docetaxel administration); 9）Active or uncontrolled severe infection (≥ CTC AE grade 2 infection) within 4 weeks before enrollment; 10）Central nervous system metastases confirmed by imaging; 11) History of other malignant tumors within the past 5 years, excluding cured cervical in-situ carcinoma, cutaneous basal cell carcinoma, cutaneous squamous cell carcinoma, and superficial bladder tumors; 12) History of psychoactive substance abuse without abstinence or mental disorders; 13) Receiving ascites/pleural effusion drainage within 2 months before enrollment, or having uncontrolled pericardial effusion, pleural effusion, or ascites; 14) Complications of pulmonary fibrosis or interstitial pneumonia, or severe chronic obstructive pulmonary disease; 15) Severe gastrointestinal diseases, such as gastric perforation, active peptic ulcer, etc.
* Concomitant Medications: 1) Requirement to use strong CYP3A inhibitors (e.g., itraconazole, telithromycin, clarithromycin, ritonavir, etc.) or moderate CYP3A inhibitors (e.g., ciprofloxacin) during the study; 2）Requirement to use strong CYP3A inducers (e.g., phenobarbital, phenytoin sodium, rifampicin, carbamazepine, etc.) or moderate CYP3A inducers during the study; 3）Requirement to take traditional Chinese medicine, especially those with antitumor activity, during the study.
* Others: 1）Anticipated use of any form of systemic or local antitumor therapy during the study; 2）Concomitant diseases or other conditions determined by the investigator to pose a serious risk to the patient's safety, potentially confound study results, or affect the patient's ability to complete the study, such as a gastrointestinal history that may affect oral drug absorption. 3）Subjects with multiple factors affecting oral drug administration (such as inability to swallow, chronic diarrhea, intestinal obstruction, etc.); 4）Allergy to the drugs in this study; 5）Administration of live vaccines within 30 days before enrollment. Live vaccines include but are not limited to: measles, mumps, rubella, varicella/zoster (chickenpox), yellow fever, rabies, Bacille Calmette-Guérin (BCG), typhoid vaccine, etc.
