The purpose of this study is to compare induction chemotherapy (gemcitabine+cisplatin) plus immunotherapy with concurrent chemoradiotherapy (CCRT) or RT alone in patients with stage III-IVa nasopharyngeal carcinoma(NPC), in order to confirm the value of Immunotherapy and concurrent chemotherapy in NPC patients.

Patients Patients with stage III-Iva(except T3N0M0) non-keratinizing NPC (UICC/AJCC 8th edition) are randomly assigned to receive immunotherapy and induction chemotherapy plus CCRT or RT alone. Patients in both groups receive Anti-PD-1 Antibody, gemcitabine (1000 mg/m² d1,8) and cisplatin (80mg/m² d1) every 3 weeks for three cycles before CCRT. The immunotherapy and induction chemotherapy plus CCRT group receive cisplatin 80-100 mg/m² every 3 weeks for 2 cycles, concurrently with intensity-modulated radiotherapy (IMRT). IMRT is given as 2.0-2.30 Gy per fraction with five daily fractions per week for 6-7 weeks to a total dose of 66 Gy or greater to the primary tumor. Our primary endpoint is failure-free survival(FFS). Secondary end points include overall survival (OS), locoregional failure-free survival (LR-FFS), distant failure-free survival (D-FFS) rates and toxic effects. All efficacy analyses are conducted in the intention-to-treat population, and the safety population include only patients who receive their randomly assigned treatment.

Inclusion Criteria:

• Patients with newly histologically confirmed non-keratinizing (according to WHO histologically type).
• Tumor staged as III-Iva(except T3N0M0) (according to the 8th AJCC edition).
• No evidence of distant metastasis (M0).
• Satisfactory performance status: Karnofsky scale (KPS) ≥ 70.
• Adequate marrow: leucocyte count ≥ 4000/μL, hemoglobin ≥ 90g/L and platelet count ≥ 100000/μL.
• Normal liver function test: Alanine Aminotransferase (ALT), Aspartate Aminotransferase (AST) < 1.5×upper limit of normal (ULN) concomitant with alkaline phosphatase (ALP) ≤ 2.5×ULN, and bilirubin ≤ ULN.
• Adequate renal function: creatinine clearance ≥ 60 ml/min.
• Patients must be informed of the investigational nature of this study and give written informed consent.

Exclusion Criteria:

• WHO Type keratinizing squamous cell carcinoma or basaloid squamous cell carcinoma.
• Age > 65 or < 18.
• Treatment with palliative intent.
• Prior malignancy except adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer.
• Pregnancy or lactation (consider pregnancy test in women of child-bearing age and emphasize effective contraception during the treatment period).
• History of previous RT (except for non-melanomatous skin cancers outside intended RT treatment volume).
• Prior chemotherapy or surgery (except diagnostic) to primary tumor or nodes.
• Any severe intercurrent disease, which may bring unacceptable risk or affect the compliance of the trial, for example, unstable cardiac disease requiring treatment, renal disease, chronic hepatitis, diabetes with poor control (fasting plasma glucose > 1.5×ULN), and emotional disturbance.