Inclusion Criteria:
1. Age ≥ 18 years old, ≤ 80 years old, gender not limited
2. Confirmed by pathological histology, patients with recurrent, unresectable, or metastatic mucosal melanoma after surgery
3. In the late stage, no systemic anti-tumor drug treatment has been received, and previous radical surgical resection, adjuvant or neoadjuvant therapy is allowed. However, it is required to be completed at least 4 weeks before randomization, and all treatment-related toxicity events have returned to normal or CTCAE 5.0 grade I or below (except for hair loss, skin hypopigmentation, well controlled hypothyroidism, and adrenal insufficiency)
4. There must be at least one measurable lesion that has not undergone local treatment (according to RECIST v1.1 requirements, the length of the measurable lesion on spiral CT or MRI scan must be ≥ 10 mm or the length of enlarged lymph nodes must be ≥ 15 mm)
5. At least one lesion that can receive radiotherapy
6. ECOG PS 0 or 1 point
7. Expected survival period ≥ 12 weeks
8. No contraindications for treatment, with sufficient organ and bone marrow function: ① Absolute neutrophil count ≥ 1.5 × 109/L ② Platelets ≥ 80 × 109/L③ Hemoglobin ≥ 90 g/L④ ALT and AST ≤ 1.5 × ULN⑤ Bilirubin ≤ 1.5 × ULN⑥ Blood creatinine ≤ 1.5 × ULN
9. Patients may have a history of brain/meningeal metastases, but they must have undergone local treatment (surgery/radiation therapy) before the start of the study and have been clinically stable for at least 3 months (corticosteroids are allowed to be used before randomization, but must be discontinued 2 weeks before starting the study drug)
10. Non surgical sterilization or female patients of childbearing age are required to use a medically approved contraceptive measure (such as intrauterine device, contraceptive pill, or condom) during the study treatment period and within 12 months after the end of the study treatment period
11. For male patients whose partners are women of childbearing age, effective contraception methods should be used during the trial period and within 12 months after the last dose. 11. Participants voluntarily join the study, sign informed consent forms, have good compliance, and cooperate with follow-up.
Exclusion Criteria:
1. Patients who have received VEGFR TKI treatment within the past 6 months (including neoadjuvant and adjuvant treatment periods)
2. Individuals known to be allergic to recombinant humanized anti-PD-1 monoclonal antibody drugs and their components
3. History of immunodeficiency, or other acquired or congenital immunodeficiency diseases, or history of organ transplantation
4. Previous thyroid dysfunction and inability to maintain normal thyroid function even with medication treatment
5. Pregnant or lactating women
6. Evidence of bleeding quality or significant coagulation dysfunction (not receiving anticoagulant therapy)
7. Bleeding events occurring within 6 months prior to the first medication due to untreated or incompletely treated esophageal and/or gastric varices
8. Major vascular disease (such as aortic aneurysm requiring surgical repair or recent peripheral arterial thrombosis) occurred within 6 months before the first use of medication
9. Insufficient control of hypertension (systolic blood pressure ≥ 140mmHg or diastolic blood pressure ≥ 90mmHg) (based on the average of BP readings obtained from ≥ 2 measurements), allowing for the use of antihypertensive therapy to achieve the above parameters
10. Previously experienced hypertensive crisis or hypertensive encephalopathy
11. Within the past 3 months, there has been severe cardiovascular disease (such as New York Heart Association Grade II or above heart disease, myocardial infarction, or cerebrovascular accident), unstable arrhythmia, or unstable angina pectoris
12. Severe, unhealed, or cracked wounds, active ulcers, or untreated fractures
13. Perform hollow needle biopsy or other minor surgery within 3 days before the first medication, excluding the placement of vascular access devices
14. Major surgery should be performed within 4 weeks before the first medication, or expected to be required during the study period
15. Those who have been treated with systemic immunosuppressive drugs (including but not limited to glucocorticoids \[\>10 mg/d prednisone or other corticosteroids with equivalent physiological doses\], cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor alpha \[TNF - α\] preparations) within 2 weeks prior to their first medication, or who are expected to require systemic immunosuppressive drugs during the study treatment period
16. Subjects who have received or will receive a live vaccine within 30 days prior to the first dose, or who are expected to use the vaccine during the expected treatment period or within 5 months after the last dose
176\. Individuals known to be allergic to any investigational drug or excipient
18\. Individuals with a history of abuse of psychotropic drugs who are unable to quit or have mental disorders
19\. Researchers determine other situations that are not suitable for inclusion in the study.
