A Study Testing Emactinib Sulfate With Chemotherapy and Immunotherapy Before Surgery for Advanced Head and Neck Cancer

Inclusion Criteria: 1. ECOG Performance Status of 0-1. 2. Histologically and/or cytologically confirmed Stage III-IVA head and neck squamous cell carcinoma (oral cavity, oropharynx, hypopharynx, or larynx). 3. Classified according to the Asia-Pacific multidisciplinary consensus (Y.Guo et al., Oral Oncol 2024): * Cohort A: Resectable\*\* (amenable to upfront surgery): T2N2-3M0, T3-4N0-2M0 (AJCC 8th edition). * Cohort B: Potentially Resectable:\*\* Cases with relative contraindications to surgery (e.g., cervical lesion directly invading skin, anterior 2/3 tongue tumor extending below the hyoid level, extension to the vallecula) or where surgery would cause significant disfigurement/functional loss, requiring discussion by an MDT (head \& neck surgery, radiology) to weigh risks vs. non-surgical options. * Cohort C: Unresectable: Tumor extensively invading skull base, extending to nasopharynx/deep nasopharyngeal wall, invading/encasing carotid artery, extending to mediastinal structures, prevertebral fascia, or cervical spine; T3-4 (N0-3) or any N2a-3 (T1-4) M0 (AJCC 8th edition). 4. Biomarker: Peripheral blood flow cytometry analysis showing that PD-1+TIM-3+CD8+ exhausted T cells account for \>10% of CD8+ T cells. 5. Adequate baseline organ function within 14 days prior to enrollment: * Hematological: White Blood Cell count (WBC) ≥4000/μL, Absolute Neutrophil Count (ANC) ≥2000/μL, Hemoglobin (HGB) ≥9 g/dL, Platelet count (PLT) ≥100,000/μL. * Renal: Serum creatinine \<1.5 times the Upper Limit of Normal (ULN) OR Creatinine Clearance (CrCl) \>60 mL/min (calculated by Cockcroft-Gault formula). * Hepatic: Total bilirubin ≤1.5x ULN (except subjects with Gilbert's syndrome, who may have total bilirubin \<3x ULN); Aspartate Aminotransferase (AST) / Alanine Aminotransferase (ALT) ≤3x ULN; Alkaline Phosphatase (ALP) ≤3x ULN; Albumin (ALB) ≥3 g/dL. 6. Ability to understand and willingness to sign the Informed Consent Form. Subjects must be willing and able to comply with the protocol, including receiving treatments and scheduled visits/examinations, including follow-up. Exclusion Criteria: 1. Prior treatment with immunotherapy (anti-PD-1, anti-PD-L1, anti-PD-L2, or anti-CTLA-4 agents) or JAK inhibitors. History of severe allergic reactions to any component of monoclonal antibodies. 2. Active autoimmune disease or condition requiring immunosuppressive therapy. Subjects requiring systemic corticosteroids or other immunosuppressive drugs prior to enrollment. 3. History of other active malignancies or active infections (including tuberculosis and hepatitis); uncontrolled infections (HIV, HBV, HCV). 4. Severe cardiac or pulmonary dysfunction, including severe cardiac insufficiency (e.g., NYHA Class III or higher) or severe pulmonary dysfunction (e.g., FEV1 \<50% predicted); history of thrombotic diseases, coagulation disorders (Prothrombin Time (PT) \>16 seconds, Activated Partial Thromboplastin Time (APTT) \>53 seconds, Thrombin Time (TT) \>21 seconds, Fibrinogen (FIB) \<1.5 g/L), bleeding tendency, or current thrombolytic/anticoagulant therapy. 5. Pregnant or lactating women. Subjects unwilling to use effective contraception during the study period.