Paclitaxel polymeric micelles 300 mg/m², IV infusion over ≥3 hours, Day 1; carboplatin AUC 5, IV infusion over 1 hour, Day 1. Each cycle consists of 3 weeks (Q3W), for a total of 3 cycles. (Efficacy assessment will be performed after 3 cycles of treatment. In the absence of disease progression, treatment may be continued until disease progression (PD), intolerable toxicity, withdrawal of informed consent, initiation of other antineoplastic therapy, death, or other protocol-specified criteria for treatment discontinuation, whichever occurs first.)

Inclusion Criteria:

• Age ≥18 and ≤75 years, male or female; Histologically or cytologically confirmed head and neck squamous cell carcinoma; Prior first-line systemic therapy (including chemotherapy, targeted therapy, and immunotherapy) with disease progression or judged by the clinician to no longer derive clinical benefit; ECOG performance status score of 0-2 and a life expectancy of at least 3 months; At least one measurable lesion on imaging according to the Response Evaluation Criteria in Solid Tumors (RECIST v1.1, Appendix 3);

Adequate major organ function, with subjects meeting the following laboratory parameters:

Complete blood count meeting the following criteria (no blood transfusion, blood products, granulocyte colony-stimulating factor, or other hematopoietic growth factors within 7 days prior to the test): WBC ≥3.0×10^9/L, ANC ≥1.5×10^9/L, platelets ≥100×10^9/L, hemoglobin ≥90 g/L; Blood biochemistry meeting the following criteria: total bilirubin ≤1.5×ULN, AST, ALT, or ALP ≤2.5×ULN (for subjects with liver metastases, ALT, AST, or ALP ≤5×ULN is permitted; for subjects with bone metastases, ALP ≤10×ULN is permitted); serum creatinine ≤1.5×ULN and creatinine clearance (calculated using the Cockcroft-Gault formula, Appendix 4) ≥50 mL/min; Adequate coagulation function, defined as INR ≤1.5×ULN and PT or APTT ≤1.5×ULN; Subjects of childbearing potential must agree to use highly effective contraceptive measures during the trial. Women of childbearing potential must have a negative serum or urine pregnancy test within 72 hours prior to the start of chemotherapy; Good compliance, able to undergo treatment and follow-up, and willing to comply with the study requirements; voluntary signing of the informed consent form.

Exclusion Criteria:

• Known allergy or intolerance to any study treatment or any excipient; Presence of uncontrolled serious medical conditions, such as severe comorbidities including severe cardiac disease, cerebrovascular disease, uncontrolled diabetes, uncontrolled hypertension, uncontrolled infection, active peptic ulcer, etc.; Other malignancies within the past 5 years, except for adequately treated basal cell or squamous cell skin cancer, localized prostate cancer after radical surgery, or ductal carcinoma in situ after radical surgery; Requirement for concomitant use of other antineoplastic drugs; Receipt of any other investigational drug or participation in another interventional clinical trial within 30 days prior to screening; History of psychotropic substance abuse with inability to abstain, or presence of psychiatric disorders; Pregnant or breastfeeding women; Patients deemed unsuitable for enrollment by the investigator.