Efficacy and Safety of TPC Induction Chemotherapy Combined With Nimotuzumab and Toripalimab "Immune Sandwich" Regimen Versus Full-Course Immunotherapy for Locally Advanced Nasopharyngeal Carcinoma

Inclusion Criteria: * Aged between 18 and 70 years, regardless of gender * Histologically or cytologically confirmed diagnosis of nasopharyngeal carcinoma * Locoregionally advanced nasopharyngeal carcinoma classified as Stage III-IVA per the 8th AJCC staging system, excluding T3-4N0 and T3N1 disease * Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 * Adequate organ and bone marrow function as demonstrated by laboratory test results obtained within 7 days prior to enrollment. No blood products, hematopoietic growth factors, albumin, or other intravenous/subcutaneous corrective medications are permitted within 14 days before laboratory testing. Specific criteria are listed below.Hematology: Absolute Neutrophil Count (ANC) ≥ 1.5 × 10⁹/L; Platelet (PLT) count ≥ 75 × 10⁹/L; Hemoglobin (HGB) ≥ 9.0 g/dL;Liver function: Total Bilirubin (TBIL) ≤ 2 × Upper Limit of Normal (ULN); Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) ≤ 5 × ULN; serum albumin ≥ 28 g/L; Alkaline Phosphatase (ALP) ≤ 5 × ULN. Renal function: Serum Creatinine (Cr) ≤ 1.5 × ULN, or Creatinine Clearance (CCr) ≥ 50 mL/min (calculated via the Cockcroft-Gault formula). For patients with urine protein ≥ 2+ on routine urinalysis, a 24-hour urine collection is required, with total 24-hour urinary protein quantification \< 1 g. Coagulation function: International Normalized Ratio (INR) ≤ 2.3, or prothrombin time (PT) prolongation ≤ 6 seconds * Able to provide written informed consent and comply with all protocol-specified study visits and related procedures. Exclusion Criteria: * Diagnosis of another malignant tumor within 5 years prior to the first study drug administration, excluding radically treated basal cell carcinoma, squamous cell carcinoma of the skin, and/or radically resected carcinoma in situ * Symptomatic congestive heart failure (New York Heart Association \[NYHA\] Class II-IV) or left ventricular ejection fraction (LVEF) \<50% on echocardiography * Patients with acute or chronically active hepatitis B or hepatitis C infection: HBV DNA \>2000 IU/mL or 10⁴ copies/mL; HCV RNA \>10³ copies/mL; concurrent positive hepatitis B surface antigen (HBsAg) and anti-HCV antibody. Subjects with viral loads below the above thresholds after nucleotide antiviral therapy are eligible for enrollment * Past or current history of pulmonary diseases including pulmonary fibrosis, interstitial pneumonia, pneumoconiosis, drug-induced pneumonitis, or severely impaired pulmonary function * Active tuberculosis (TB) receiving anti-tuberculosis treatment, or having received anti-tuberculosis therapy within 1 year before the first study drug dose. * Human immunodeficiency virus (HIV) infection (positive HIV 1/2 antibody), or known syphilis infection requiring treatment * Severe active or poorly controlled infections. Severe infection requiring hospitalization within 4 weeks before the first dose, including but not limited to complications from infection, bacteremia, or severe pneumonia * History of active autoimmune diseases requiring systemic therapy (e.g., disease-modifying agents, corticosteroids, immunosuppressants) within 2 years prior to the first dose. Replacement therapies (e.g., thyroxine, insulin, physiological corticosteroids for adrenal or pituitary insufficiency) are permitted. Known history of primary immunodeficiency. Subjects with only positive autoantibodies will be assessed by the investigator to confirm the presence of autoimmune disease * Female patients who are pregnant or breastfeeding * Prior radiotherapy, chemotherapy, or surgery for nasopharyngeal and cervical lesions (excluding biopsy) * History of hypersensitivity to any study drug or its components