Safety and Efficacy of SCT200 in Head and Neck Squamous Cell Carcinoma

Inclusion Criteria: * Voluntarily participate in this clinical trial and sign an informed consent form; * Male or female, age ≥ 18 and ≤ 75 years old; * The estimated survival period is ≥ 3 months; * ECOG fitness status score 0 to 1; * Recurrent and/or metastatic HNSCC (except nasopharyngeal carcinoma) diagnosed by pathology and unable to receive topical treatment (surgery or radiotherapy); * Patients who have been treated with platinum (cisplatin/carboplatin/nidaplatin) and have clear disease progression during treatment (at least 2 cycles) or after treatment (see RECIST version 1.1) or side effects Intolerance, and the minimum dose of platinum drugs must meet: * Minimum dose of cisplatin: ≥60mg/m2 per cycle, or ≥120mg/m2 in 8 weeks; * The minimum dose of carboplatin: AUC ≥ 4 / cycle, or total AUC ≥ 8 within 8 weeks. * If cisplatin is converted to platinum, the platinum dosage can be calculated using the following formula: carboplatin 1AUC = cisplatin 15mg/m2; * The minimum dose of nedaplatin: ≥80mg/m2 per cycle, or ≥160mg/m2 in 8 weeks; Note: Platinum drugs can be used as adjuvant therapy for postoperative patients (synchronous radiotherapy), for palliative chemotherapy in patients with advanced stage or in patients with recurrent and/or metastatic disease. * Laboratory inspection: * Blood routine: neutrophils ≥1.5×l09/L, platelets≥75×109/L, hemoglobin≥80g/L; * Liver function: alanine aminotransferase (ALT) and aspartate aminotransferase (AST), ALT and AST ≤ upper limit of normal value × 3 for liver metastasis, ALT and AST ≤ upper limit of normal value for liver metastases × 5; total bilirubin ( TBIL) ≤ upper limit of normal value × 1.5; * Renal function: creatinine (Cr) ≤ normal upper limit × 1.5; * Electrolyte: Magnesium ≥ normal lower limit; * According to the RECIST standard version 1.1, there is at least one measurable tumor lesion. For lesions that have received previous radiotherapy, the target lesion can only be selected if there is a clear disease progression 3 months after the end of radiotherapy. Exclusion Criteria: * Patients with a history of central nervous system metastasis or a history of central nervous system metastasis before screening. For patients with clinically suspected central nervous system metastasis, imaging confirmation must be performed within 28 days prior to enrollment to exclude central nervous system metastasis; * There are other medical history of malignant tumors, except that the malignant lesions have been treated with therapeutic measures 5 years or more before enrollment and there are no known active lesions. The investigator judges that the risk of recurrence is low; Non-melanoma skin cancer, and no evidence of worsening disease; adequately treated cervical cancer in situ, and no evidence of worsening disease; prostatic intraepithelial neoplasia, no evidence of prostate cancer recurrence; * known to be allergic to antibodies or other components contained in the test drug; * have received EGFR antibodies (such as panitumumab, cetuximab or its analogs), or small molecule EGFR inhibitors (such as gefitinib, erlotinib, lapatinib, etc.); * In the 4 weeks or 4 weeks before enrollment, they received anti-tumor drugs (such as chemotherapy, hormone therapy, immunotherapy, antibody therapy, radiotherapy, etc.) or received research drug treatment and could not be included in the evaluation by the investigator. Pain-free palliative radiotherapy for bones; * At the time of enrollment, patients still had ≥2 toxic side effects (except for hair loss, hearing loss, tinnitus, dry mouth or platinum-induced grade 2 neurotoxicity) caused by previous anti-tumor treatment; * Patients have been enrolled in other study devices or study drug studies at screening time, or have been deactivated for less than or equal to 4 weeks from other study drugs or study devices; * Conduct or plan major surgery within 4 weeks prior to enrollment; * Received transfusion, erythropoietin (EPO), granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) within 2 weeks prior to enrollment; * Clinically significant cardiovascular disease (defined as: unstable angina, symptomatic congestive heart failure (New York Heart Association \[NYHA\] ≥ II), uncontrollable severe arrhythmia); * Myocardial infarction occurred within 6 months prior to enrollment; * History of interstitial lung disease (ILD), such as interstitial pneumonia, pulmonary fibrosis, or evidence of ILD on baseline chest CT or MRI; * have clinical symptoms, require clinical intervention or serous effusion (such as pleural effusion and ascites) with a stabilization time of less than 4 weeks; * medical or psychiatric history or laboratory abnormal medical history that may interfere with the interpretation of the results; * Patients who are pregnant or breast-feeding, or who plan to be pregnant during the treatment period and within 6 months after the end of treatment; * Patients (including male or female patients) who are unwilling to receive effective contraception during the treatment period and within 6 months after the end of treatment; * HCV antibody positive; or HIV positive; or HBV test results: HBsAg positive and / or HBcAb positive and HBV DNA ≥ 104 copy number or ≥ 2000 IU / ml; * Patients have active or uncontrollable infections (except for simple urinary tract infections or upper respiratory tract infections) requiring systemic treatment within 2 weeks or 2 weeks prior to enrollment; * known patients have alcohol or drug addiction; * The investigator believes that patients have other conditions that may affect their adherence to protocol adherence and study indicators, and are not suitable for patients participating in the study.