• Disease control rate [ Time Frame: After 3 cycles of GP chemothrapy plus PD-1 antibody (each cycle is 21 days) ]
  Patient's short-term effect
• Progression free survival [ Time Frame: 3 years ]
  From date of recruitment to disease progression
• Overall survival [ Time Frame: 3 years ]
  From date of recruitment to disease progression
• Adverse effects [ Time Frame: through study completion, an average of 3 months ]
  Evaluating with CTCAE v5.0
• Quality of life: EuroQoL 5 dimension [ Time Frame: through whole study, an average of 3 years ]
  Evaluating with questionnaire of EuroQoL 5 dimension, 5 level health state utility index (EQ-5D-5L)

• Drug: PD-1 blocking antibody
  Toripalimab is an antibody targeting PD-1 developed by Shanghai Junshi Biosciences Co., Ltd.
  Other Name: JS001
• Drug: Chemotherapy
  Cisplatin and Gemcitabine
• Radiation: IMRT
  IMRT 60-66Gy, 1.8-2.0Gy/f/day

Inclusion Criteria:

• Diagnosed as local recurrence ± regional recurrence after ≥1 year of radical treatment;
• Not suitable for surgery;
• Newly histologic diagnosis of NPC (WHO II/III);
• Clinical stage rII-IVa (AJCC/UICC 8th);
• ECOG 0-1 point;
• PRANCIS score > 252 points;
• No treatment to rNPC, such as radiotherapy, chemotherapy, immunotherapy or biotherapy;
• No contraindications to immunotherapy or chemoradiotherapy;
• Adequate marrow function: WBC count ≥ 3×10E9/L, NE count ≥ 1.5×10E9/L, HGB ≥ 90g/L, PLT count ≥ 100×10E9/L;
• Adequate liver function: ALT/AST ≤ 2.5×ULN, TBIL ≤ 2.0×ULN;
• Adequate renal function: BUN/CRE ≤ 1.5×ULN or endogenous creatinine clearance ≥ 60ml/min (Cockcroft-Gault formula);
• Take effective contraceptions during and two months after treatment;
• Patients must be informed of the investigational nature of this study and give written informed consent.

Exclusion Criteria:

• Have recurrence with local necrosis;
• Have ≥G3 late toxicities, except for skin, subcutaneous tissue or mucosa;
• Unexplained fever > 38.5 ℃, except for tumor fever;
• Treated with ≥ 5 days antibiotics one month before enrollment;
• Have active autoimmune disease (e.g., uveitis, enteritis, hepatitis, hypophysitis, nephritis, vasculitis, hyperthyroidism, and asthma requiring bronchodilator therapy);
• Have a known history of human immunodeficiency virus (HIV), active Hepatitis B (HBV-DNA ≥10E3copiers/ml) or hepatitis C virus (HCV) antibody positive;
• Have previously treated with PD-1 antibody or other immunotherapy for PD-1/PD-L1 pathway;
• Have New York Heart Association (NYHA) class 3 or 4, unstable angina, myocardial -infarction within 1 year, or clinically meaningful arrhythmia that requires treatment;
• Have known allergy to large molecule protein products or any compound of study therapy;
• Pregnant or breastfeeding;
• Prior malignancy except adequately treated non-melanoma skin cancer, in situ cervical cancer, and papillary thyroid carcinoma;
• Have received a live vaccine within 30 days of planned start of study therapy Has psychiatric drug or substance abuse disorders that would interfere with cooperation with the requirements of the trial;
• Any other condition, including mental illness or domestic/social factors, deemed by the investigator to be likely to interfere with a patient's ability to sign informed consent, cooperate and participate in the study, or interferes with the interpretation of the results.