This trial aims to study the role of Adebrelimab combined with induction chemotherapy plus concurrent chemoradiotherapy (IC+CCRT) for high-risk locoregionally advanced nasopharyngeal carcinoma(LANPC).

The trial plans to enroll patients with stage IVA+T3N2M0 (AJCC 8th) locoregionally-advanced nasopharyngeal carcinoma (LANPC). Patients receive 3 cycles of induction chemotherapy with gemcitabine and cisplatin and concurrent cisplatin-radiation plus Adebrelimab in induction chemotherapy and adjuvant chemotherapy. Adebrelimab will begin on day 1 of induction chemotherapy and continue every 3 weeks for 3 cycles in induction therapy and for 9 cycles in adjuvant therapy.

Inclusion Criteria:

1. Patients with histologically confirmed nasopharyngeal carcinoma.
2. Tumor staged as IVA+T3N2M0 (AJCC 8th).
3. Eastern Cooperative Oncology Group performance status ≤1.
4. Adequate marrow function: neutrocyte count≥1.5×10e9/L, hemoglobin ≥90g/L and platelet count ≥100×10e9/L.
5. Alanine Aminotransferase (ALT)/Aspartate Aminotransferase (AST) ≤2.5×upper limit of normal (ULN), and bilirubin ≤ 1.5×ULN.
6. Adequate renal function: creatinine clearance rate ≥ 60 ml/min (Cockcroft-Gault formula).
7. Patients must be informed of the investigational nature of this study and give written informed consent.
8. Women of childbearing potential (WOCBP) who are sexually active must be willing to adhere to effective contraception during treatment and for 1 year after the last dose of study drug. Men who are sexually active with WOCBP must be willing to adhere to effective contraception during treatment and for 1 year after the last dose of the study drug

Exclusion Criteria:

1. Age > 65 or < 18.
2. Hepatitis B surface antigen (HBsAg) positive and hepatitis B virus DNA >1×10e3 copies/ml or 200IU/ml
3. Hepatitis C virus (HCV) antibody positive
4. Has active autoimmune disease, except type I diabetes, hypothyroidism treated with replacement therapy, and skin disease that doesn't require systemic treatment (e.g., vitiligo, psoriasis, or alopecia).
5. Has any condition that required systemic corticosteroid (equivalent to prednisone >10mg/d) or other immunosuppressive therapy within 28 days before informed consent. Patients received systemic corticosteroid equivalent to prednisone ≤10mg/d, inhale or topical corticosteroid will be allowed.
6. Has a known history of active TB (bacillus tuberculosis) within 1 year; patients with adequately treated active TB over 1 year ago will be allowed.
7. Has a known history of interstitial lung disease.
8. Has received a live vaccine within 30 days before informed consent or will receive a live vaccine in the near future.
9. Is pregnant or breastfeeding.
10. Prior malignancy within 5 years, except in situ cancer, adequately treated non-melanoma skin cancer, and papillary thyroid carcinoma.
11. Has known allergy to large molecule protein products or any compound of Adebrelimab.
12. Has a known history of human immunodeficiency virus (HIV) infection.
13. 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 interfere with a patient's ability to sign informed consent, cooperate and participate in the study, or interferes with the interpretation of the results.

Complete de-identified patient data set will be submitted onto an online platform.