This is a randomized Phase II trial to study the effectiveness and toxicity of neoadjuvant and adjuvant PD-1 antibody Toripalimab combined with concurrent cisplatin chemoradiotherapy versus cisplatin concurrent chemoradiotherapy plus placebo in treating patients with high risk locoregionally advanced nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is endemic in Southern China and Southeast Asia. For locoregionally advanced NPC, especially for the high risk NPC (plasma EBV DNA ≥ 1500 copies/ml), the incidence of treatment failure is still high. Although concurrent chemoradiotherapy (CCRT) can improve the treatment outcomes of these patients, approximately 25% of locoregionally advanced NPCs still develop relapse and metastasis.

Hence, there is an urgent need for novel therapies to improve survival and reduce treatment-related toxicity in NPC patients. Accumulating evidence shows that PD-1 antibody is effective for treating recurrent/metastastic NPC patients. This is a Phase II randomized trial to study the effectiveness and toxicity of neoadjuvant and adjuvant PD-1 antibody Toripalimab combined with CCRT versus CCRT plus placebo in treating patients with high risk NPC (Stage III-IVa, AJCC 8th and EBV DNA ≥ 1500 copies/ml).

Inclusion Criteria:

1. Patients with newly histologically confirmed non-keratinizing nasopharyngeal carcinoma, including WHO II or III Original clinical staged as III-IVa （according to the 8th AJCC edition）
2. No evidence of distant metastasis (M0)
3. Plasm EB Virus DNA≥1500copies/ml
4. Male and no pregnant female
5. Satisfactory performance status: ECOG (Eastern Cooperative OncologyGroup) scale 0-1
6. WBC ≥ 4×109 /L and PLT ≥4×109 /L and HGB ≥90 g/L
7. With normal liver function test (ALT、AST ≤ 2.5×ULN, TBIL≤ 2.0×ULN)
8. With normal renal function test ( creatinine clearance ≥60 ml/min)

Exclusion Criteria:

1. Patients have evidence of relapse or distant metastasis
2. Histologically confirmed keratinizing squamous cell carcinoma (WHO I)
3. Receiving radiotherapy or chemotherapy previously
4. The presence of uncontrolled life-threatening illness
5. Women of child-bearing potential who are pregnant or breastfeeding because of the potentially dangerous effects of the preparative chemotherapy on the fetus or infant.
6. Suffered from other malignant tumors (except the cure of basal cell carcinoma or uterine cervical carcinoma in situ) previously.
7. Patients who have been treated with inhibitors of immune regulation (CTLA-4, PD-1, PD-L1, etc.).
8. Patients with immunodeficiency disease and history of organ transplantation.
9. Patients who have used large doses of glucocorticoids, anti-cancer monoclonal antibodies, and other immunosuppressive agents within 4 weeks.
10. HIV positive.
11. Patients with significantly lower heart, liver, lung, kidney and bone marrow function.
12. Severe, uncontrolled medical conditions and infections.
13. At the same time using other test drugs or in other clinical trials.
14. Refusal or inability to sign informed consent to participate in the trial.
15. Other treatment contraindications.
16. Emotional disturbance or mental illness, no civil capacity or limited capacity for civil conduct.
17. Hepatitis B surface antigen (HBsAg) positive and HBVDNA ≥1000cps/ml.
18. Patients with positive HCV antibody test results can only be included in the study when the polymerase chain reaction of HCV RNA is negative.