Inclusion Criteria:
1. Voluntarily sign the ICF;
2. Recurrent/metastatic HNSCC diagnosed histologically or cytologically in the oral, oropharyngeal, pharyngeal, and laryngeal regions;
3. Male/female, ≥ 18 years old, ECOG 0\~1;
4. After PD-1 and platinum therapy, or PD-1 monotherapy, disease progression occurs within 12 weeks after the last ICI administration (as assessed by RECIST 1.1);
5. Target lesion (RECIST 1.1);
6. Previous PD-L1 expression test results may provide tissue for PD-L1 immunohistochemical testing;
7. Expected to survive for more than 3 months;
8. The main organ functions must meet the following requirements (laboratory test values within 7 days before enrollment must meet the following standards):
* Blood routine examination: (No blood transfusion, no use of granulocyte colony-stimulating factor, no medication correction within 14 days before screening): a) Neutrophils ≥ 1.5 × 109/L; b) Platelets ≥ 75 × 109/L; c) Hemoglobin ≥ 90g/L; ② Biochemical examination: (No albumin transfusion within 14 days before screening): a) Blood creatinine ≤ 1.5 x upper limit of normal (ULN), or creatinine clearance rate\>50 mL/min; b) Serum total bilirubin ≤ 1.5 × ULN; c) Aspartate transaminase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × ULN; ③ Coagulation function: a) International normalized ratio (INR) ≤ 2.3 or prothrombin time (PT) exceeding the normal control range ≤ 6 seconds.
Exclusion Criteria:
1. Suitable for local treatment;
2. Merge with other malignant tumors;
3. Brain metastasis;
4. If the toxicity does not recover to level 0-1 after surgery/radiotherapy/drug treatment, excluding chronic toxicity;
5. Allergic to known medication ingredients;
6. Major surgeries, radiation therapy (excluding palliative care), chemotherapy, immunotherapy, and biologics within 4 weeks prior to enrollment;
7. Received TKI, palliative surgery, and non-specific immunomodulatory therapy (such as thymosin and interferon) within 2 weeks before enrollment;
8. Received traditional Chinese patent medicines and simple preparations within one week before enrollment;
9. Use immunosuppressive drugs within 4 weeks before enrollment (excluding short-term, local, and physiological dose hormone therapy);
10. Patients with the following infection conditions:
Active infections require systemic use of antibiotics; Active mycobacterium tuberculosis infection (i.e. tuberculosis infection); Hepatitis C virus antibody (HCV Ab) positive and hepatitis C virus ribonucleic acid (HCV-RNA) positive; Hepatitis B virus deoxyribonucleic acid (HBV-DNA) ≥ 1000 IU/mL; History of human immunodeficiency virus (HIV) infection or HIV antibody positivity during screening period.
11. Uncontrollable pleural effusion, abdominal effusion, and pericardial effusion;
12. Previous grade ≥ 3 irAE or grade ≥ 2 myocarditis;
13. Have a serious history of cardiovascular and cerebrovascular diseases, including but not limited to:
Major cardiovascular and cerebrovascular diseases (such as congestive heart failure, acute myocardial infarction, unstable angina, stroke, transient ischemic attack, deep vein thrombosis or pulmonary embolism, etc.) occurred within 6 months before the first administration; Corrected QT interval (QTcF)\>480 milliseconds; Echocardiography (ECHO) indicates that the subject's left ventricular ejection fraction (LVEF) is less than 50%; New York Heart Association (NYHA) heart function classification ≥ 2; Clinically uncontrollable hypertension (note: diastolic blood pressure ≥ 100mmHg or systolic blood pressure ≥ 160mmHg. If blood pressure is controlled with or without intervention, subjects can continue to be screened); Other cardiovascular and cerebrovascular diseases that have been evaluated by the researchers as unsuitable for participation in this study;
14. Active autoimmune diseases;
15. There is a significant risk of bleeding;
16. Receive a live vaccine within 4 weeks before enrollment;
17. During pregnancy or lactation, subjects with fertility do not receive contraceptive measures;
18. The presence of mental illness may affect the conduct of clinical trials;
19. History of organ transplantation or stem cell transplantation.
