Pembrolizumab and Induction Chemotherapy in Locally Advanced HNSCC

Inclusion Criteria: 1. Histologically or cytologically confirmed Head and Neck Squamous Cell Carcinoma (oral cavity, oropharynx, laryngeal and hypopharynx) with locoregionally-advanced disease stage III or IVA without metastasis , previously untreated (AJCC 8th) and had at least one tumour lesion measurable per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 2. Measurable disease based on RECIST 1.1 3. ECOG performance status 0-1 4. Men and women, Age ≥18 and ≤ 70 years at the time of signing informed consent, 5. Adequate hepatic, cardiac and renal function as demonstrated by 1) Hematology: ANC≥1.5×10\^9 /L, HGB≥9 g/dL, PLT≥80×10\^9 /L; 2) Renal: Serum creatinine \< 1.5x ULN or CrCl \> 60mL/min; 3) Hepatic: Total Bilirubin ≤ 1.5 x ULN, AST/ALT ≤ 2.5 x ULN and ALP≤5 x ULN. 6. Female subjects of childbearing potential should have a negative pregnancy test result within 28 days prior to enrollment. If the result is more than 7 days before receiving the first dose of study medication, a urine pregnancy test is required for verification. 7. Voluntary informed consent, joining the study with good compliance Exclusion Criteria: 1. Active, known, or suspected autoimmune disease or Type I diabetes or hypothyroidism requiring hormone replacement therapy and skin diseases requiring systemic treatment. 2. currently received systemic steroid therapy with dose superior to 10 mg/day of prednisone or equivalent or any other form of immunosuppressive therapy within 14 days prior to the enrollment 3. Has known active Hepatitis B (e.g., HBsAg reactive and HBV DNA≥1×10\^4 copies /mL) or Hepatitis C or HIV 4. Active pulmonary tuberculosis (TB) infection was judged according to chest X-ray examination/CT, sputum examination and clinical physical examination. 5. Patients with severe heart disease include congestive heart failure, uncontrollable high-risk arrhythmias, unstable angina pectoris, myocardial infarction, and intractable hypertension. 6. Pregnant or breastfeeding women. 7. The patient (male or female) has the possibility of fertility, but is unwilling or does not take effective contraceptive measures. 8. Currently participating and receiving study therapy or has participated in a study of an investigational agent and received study therapy or used an investigational device 9. Has had another known invasive malignancy or unresectable cancer. 10. Received a live vaccine within 30 days of planned start of study therapy. 11. History or current evidence of any condition, therapy, or laboratory abnormality that might influence the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator.