Camrelizumab in Combination With Cetuximab and Chemotherapy for Relapsed/Metastatic HNSCC Patients

Main inclusion Criteria: 1. Histologically- or cytologically-confirmed recurrent disease not amenable to curative treatment with local or systemic therapy, or metastatic (disseminated) HNSCC. 2. Patients with distant metastases, or patients with local recurrence who are not suitable for local radical therapy, must have previously received radiotherapy (postoperative radiotherapy or radical radiotherapy) for local recurrence and must have ended radiotherapy more than 6 months ago. 3. Patients who have not received systemic chemotherapy before and who have received systemic chemotherapy as part of multidisciplinary treatment 6 months ago for locally advanced disease can be enrolled. 4. Age 18-70 years old. 5. ECOG performance status 0-1. 6. Patients must have at least one lesion that can be evaluated by enhanced CT or MRI according to Recist v1.1. 7. Hematopoietic function of bone marrow is basically normal: WBC ≥ 3.5 × 109/L, ANC ≥ 1.5 × 109/L, PLT ≥ 80 × 109/L, Hb ≥ 90 g/L. 8. Liver and kidney functions are basically normal: total bilirubin, ALT and AST are all\<1.5 × UNL (upper limit of normal value); Cr \< 1.5 × UNL, and creatinine clearance ≥ 50 ml/min. 9. Patients must have a life expectancy of at least 3 months. 10. Patients volunteered to sign informed consent. Main exclusion Criteria: 1. Patients with a known history of severe allergy to monoclonal antibody therapy. 2. Patients with previous camrelizumab therapy or previous cetuximab therapy (cetuximab as part of therapy in multidisciplinary therapy for curative purposes may be included). 3. Patients with clinically significant heart disease, including severe cardiac insufficiency: New York College of Cardiology (NYHA) Grade IV cardiac insufficiency, unstable angina, acute myocardial infarction within 6 months prior to screening, congestive heart failure, Q-Tc interval greater than 500ms. 4. Patients who had received secondary or higher gardes surgery within 3 weeks prior to treatment. 5. Patients suffering from autoimmune disease requiring treatment, or syndrome history requiring systemic use of steroids/immunosuppressants, such as hypophysitis, pneumonia, colitis, hepatitis, nephritis, hyperthyroidism, hypothyroidism, etc. 6. Other serious and uncontrollable concomitant diseases that may affect the compliance of the scheme or interfere with the interpretation of the results, including uncontrollable diabetes, or pulmonary diseases (interstitial pneumonia, obstructive pulmonary disease, and symptomatic bronchospasm history). 7. Patients have evidence of central nervous system disease. 8. Patients with known hepatitis B (HBV) (HBsAg positive and HBV DNA ≥ 103IU/ml) and hepatitis C (HCV) infection (HCV antibody positive and HCV RNA detectable); And other subjects with acquired and congenital immunodeficiency diseases, including but not limited to those infected with AIDS virus. 9. Pregnant or lactating woman. 10. Patients have serious active infection. 11. Patients have a history of serious neurological or psychiatric diseases, including dementia or epilepsy. 12. Patients may interfere with the drug abuse, medical, psychological or social conditions of the subject involved in the study or the evaluation of the study results. 13. Patients considered unsuitable by the investigator.