• Voluntarily sign the informed consent form and comply with the protocol requirements;

• No gender restrictions;

• Age ≥18 years and ≤75 years;

• Expected survival time ≥3 months;

• Histologically or cytologically confirmed head and neck squamous cell carcinoma occurring only in the oral cavity, oropharynx, hypopharynx, and larynx;

• Agree to provide archived tumor tissue specimens or fresh tissue samples from primary or metastatic lesions;

• Must have at least one measurable lesion as defined by RECIST v1.1;

• Performance status score: ECOG ≤1;

• Toxicity from prior anti-tumor therapy has recovered to ≤ Grade 1 as defined by NCI-CTCAE v5.0;

⁃ No severe cardiac dysfunction, with left ventricular ejection fraction (LVEF) ≥50%;

⁃ Organ function levels must meet the requirements;

⁃ Coagulation function: International Normalized Ratio (INR) ≤1.5, and activated partial thromboplastin time (APTT) ≤1.5 × ULN;

⁃ Urine protein ≤1+ or ≤1000 mg/24h;

⁃ Female subjects of childbearing potential or male subjects with partners of childbearing potential must use highly effective contraception from 7 days before the first dose until 24 weeks after the last dose. Female subjects of childbearing potential must have a negative serum pregnancy test within 7 days before the first dose.