Inclusion Criteria:
1. Age between 18 and under 80 years old.
2. Pathologically confirmed head and neck malignancies (including nasopharyngeal carcinoma, oral cavity cancer, oropharyngeal cancer, laryngeal cancer, hypopharyngeal cancer, salivary gland cancer, nasal cavity and paranasal sinus cancer, etc.); patients who have failed at least two lines of standard treatment (including cetuximab and immuno check point inhibitors).
3. Expected survival ≥3 months.
4. Eastern Cooperative Oncology Group Performance Status (ECOG PS) score of 0-2.
5. Pre-treatment peripheral blood tests meet the following conditions: neutrophil count \>2000/mm³, platelet count \>100,000/mm³.
6. Pre-treatment liver and kidney function meet the following: bilirubin \<1.5 mg/dL, AST or ALT \<1.5 times the upper limit of normal, serum creatinine \<1.5 mg/dL, creatinine clearance \>60 mL/min.
7. Agreement to follow the trial treatment plan and visit schedule, voluntary participation, and written informed consent.
Exclusion Criteria:
1. Expected survival less than 3 months.
2. Positive pregnancy test for women of childbearing age.
3. Concurrent diseases or conditions that affect the patient's ability to enroll normally or safety during the study period.
4. Active psychiatric disorders or other psychological conditions that affect the patient's ability to sign the informed consent or understand the study.
5. Severe coagulation abnormalities and/or active infection requiring intravenous anti-infective therapy.
6. History of another malignancy within 5 years prior to screening, except for basal cell carcinoma of the skin, squamous cell carcinoma of the skin, or microscopic papillary thyroid carcinoma that have been treated with potential curative therapy.
7. Severe cardiac arrhythmia or conduction abnormalities, and clinically uncontrolled hypertension (systolic blood pressure \>150 mmHg and/or diastolic blood pressure \>90 mmHg).
8. Adverse reactions from prior anti-tumor treatments have not recovered to CTCAE version 5.0 Grade \<1 (except for toxicities judged by the investigator to pose no safety risk, such as alopecia, Grade 2 peripheral neuropathy, etc.).
9. History of infectious diseases, such as positive HIV antibody test, active hepatitis B (defined as HBsAg positive during screening, with HBV-DNA levels above the upper limit of normal at the local laboratory), or hepatitis C (defined as positive HCV-Ab test during screening with positive HCV-RNA).
10. Other conditions considered by the investigator to potentially affect patient compliance or make the patient unsuitable for participation in this study.
