This is a phase 3, multicentre, randomised controlled trial to study the effectiveness and toxicity of PD-1 antibody Toripalimab combined with concurrent cisplatin chemoradiotherapy versus cisplatin concurrent chemoradiotherapy alone in treating patients with locoregionally recurrent nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is endemic in southern China, southeast Asia, and northern Africa. According to a survey from the International Agency for Research on Cancer, there were an estimated 129,079 new cases and 72,987 related deaths in 2018. Radiotherapy is the primary treatment option. Due to advances in disease management, diagnostic imaging, radiotherapy technology, and the broader application of systemic therapy, the prognosis of NPC has improved signifificantly.Nevertheless, localregional recurrence will occur in about 10% patients. Because of radiation resistance, the prognosis of re-irradiation is poor for recurrent nasopharyngeal carcinoma.

Hence, there is an urgent need for novel therapies to improve survival and reduce treatment-related toxicity in recurrent NPC patients. Emerging evidence shows that PD-1 antibody is effective for treating recurrent/metastastic NPC patients. This is a phase 3, multicentre, randomised controlled trial to study the effectiveness and toxicity of neoadjuvant and adjuvant PD-1 antibody Toripalimab combined with concurrent chemoradiotherapy (CCRT) versus CCRT alone in treating patients with locoregionally recurrent nasopharyngeal carcinoma.

Inclusion Criteria:

1. Patients with newly histologically confirmed recurrent nasopharyngeal carcinoma, or Two or more image examinations (MRI, and PET-CT) show the recurrent tumor
2. staged as rT3-4N0-1M0或rT1-4N2-3M0 （according to the 8th AJCC edition）
3. Satisfactory performance status: ECOG (Eastern Cooperative OncologyGroup) scale 0-1
4. Neutrophil ≥ 1.5×109 /L and PLT ≥4×109 /L and HGB ≥90 g/L
5. With normal liver function test (ALT、AST ≤ 2.5×ULN, TBIL≤ 1.5×ULN)
6. With normal renal function test ( creatinine clearance ≥60 ml/min)
7. sign an "informed consent form
8. Male and no pregnant female

Exclusion Criteria:

1. Age older than 65, or younger than 18 years old
2. Hepatitis B surface antigen (HBsAg) positive and HBV-DNA ≥200IU/ml, or 1000cps/ml.
3. Patients with positive HCV antibody.
4. Active, known or suspected autoimmune disease; Type I Diabetes, hypothyroidism those only need hormone replacement therapy, and skin disease (leukoderma, psoriasis, alopecia et al) who don't need systemic therapy can recruit.
5. History of interstitial lung disease
6. Equivalent dose more than prednisone 10mg/d or other immunosuppressive treatments within 28 days prior to signing the informed consent.
7. Receive or will receive live vaccine within 30 days prior to signing the informed consent.
8. Women of child-bearing potential who are pregnant or breastfeeding.
9. Suffered from malignant tumors, except the carcinoma in situ, papillary thyroid carcinoma, or skin cancer (non- melanoma) within five years.
10. Hypersensitivity to macromolecular protein, or to any component of triplezumab.
11. HIV positive.
12. Severe, uncontrolled medical conditions and infections.
13. Other diseases which may influence the safety or compliance of the clinical trial, such as heart failure with symptom, unstable angina, myocardial infarction, active infections those need systemic therapy, mental illness, or their family and society factors.

We will share the safety and efficacy data of the study