Toripalimab Vs. Placebo Wtih GP Induction Chemotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma

Inclusion Criteria:

1. Voluntarily participates and signs an informed consent form.

2. Aged 18-70 years, male or non-pregnant female.

3. Pathologically confirmed nasopharyngeal non-keratinizing carcinoma (differentiatedor undifferentiated, i.e., WHO Type II or III).

4. Staging of any T, N2-3 or T4N1 (9th AJCC/UICC staging), with no distant metastasis.

5. ECOG performance status score of 0-1.

6. Hemoglobin (HGB) ≥90 g/L, neutrocyte count≥1.5×10⁹/L, platelets (PLT) ≥100×10⁹ /L.

7. Liver function: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST)≤2.5×upper limit of normal (ULN), and bilirubin ≤ 1.5×ULN.

8. Adequate renal function: creatinine clearance rate ≥ 60 ml/min (Cockcroft-Gaultformula).

9. Women of childbearing potential (WOCBP) who are sexually active must be willing toadhere to effective contraception during treatment and for 1 year after the lastdose of the study drug. Men who are sexually active with WOCBP must be willing toadhere to effective contraception during treatment and for 1 year after the lastdose of the study drug.

Exclusion Criteria:

1. Age > 70 years or < 18 years.

2. Patients with recurrence or distant metastases.

3. Pathologically confirmed nasopharyngeal keratinizing squamous cell carcinoma (WHOType I).

4. Patients who have previously undergone radiotherapy or systemic chemotherapy.

5. Hepatitis B surface antigen (HBsAg) positive and hepatitis B virus DNA >1000copies/ml or 200IU/ml.

6. Hepatitis C virus (HCV) antibody positive.

7. Has active autoimmune disease, except type I diabetes, hypothyroidism treated withreplacement therapy, and skin disease that doesn't require systemic treatment (e.g.,vitiligo, psoriasis, or alopecia).

8. Has any condition that required systemic corticosteroid (equivalent to prednisone >10mg/d) or other immunosuppressive therapy within 28 days before informed consent.Patients who received systemic corticosteroid equivalent to prednisone ≤10mg/d,inhale or topical corticosteroids will be allowed.

9. Has a known history of active bacillus tuberculosis within 1 year; patients withadequately treated active bacillus tuberculosis over 1 year ago will be allowed.

10. Has a known history of interstitial lung disease.

11. Has received a live vaccine within 30 days before informed consent or will receive alive vaccine in the near future.

12. Is pregnant or breastfeeding.

13. Prior malignancy within 5 years, except in situ cancer, adequately treatednon-melanoma skin cancer and papillary thyroid carcinoma.

14. Has known allergy to large molecule protein products or any compound of toripalimab.

15. Has a known history of human immunodeficiency virus infection.

16. Any other condition, including symptomatic heart failure, unstable angina,myocardial infarction, active infection requiring systemic therapy, mental illness,or domestic/social factors, deemed by the investigator to be likely to interferewith a patient's ability to sign informed consent, cooperate and participate in thestudy or interferes with the interpretation of the results.