This study is a randomized, double-blind, multi-center phase III clinical study to compare the efficacy and safety of penpulimab combined with chemotherapy and placebo combined with chemotherapy in the first-line treatment of recurrent or metastatic nasopharyngeal carcinoma.

Inclusion Criteria:

• Voluntarily signed written Informed Consent Form(ICF).
• Main study: Age of ≥ 18 years and ≤ 75 years at the time of enrollment.
• Substudy: Age of ≥ 12 years and < 18 years. Weight≥ 35KG.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Expected survival of ≥ 3 months.
• Histologically or cytologically confirmed nasopharyngeal carcinoma.
• Subjects with primary metastatic (nasopharyngeal carcinoma, stage IVB defined by the Union for International Cancer Control and the American Joint Committee on Cancer Staging System edition 8) nasopharyngeal carcinoma who are not suitable for local treatment or radical treatment; subjects who have a local-regional recurrence and/or distant metastasis more than 6 months after the completion of prior radical treatment (radiotherapy with induction, concurrent, adjuvant chemotherapy)； No systemic treatment has been received for recurrent or metastatic diseases, not amendable to local treatment or have received local treatment for the local-regional recurrent disease
• At least one measurable lesion according to RECIST v1.1;
• Has adequate organ function.
• All female and male subjects of reproductive potential must agree to use an effective method of contraception, as determined by the Investigator, during and for 150 days after the last dose of study treatment.

Exclusion Criteria:

• Subjects with pathologically diagnosed nasopharyngeal adenocarcinoma or sarcoma.
• Subjects have had another malignancy within 3 years before the first dose, except nasopharyngeal carcinoma. Subjects with other malignancies that have been cured by local therapy such as basal or cutaneous squamous cell carcinoma, superficial bladder cancer, cervix or breast carcinoma in situ are not excluded.
• Participation in treatment with an investigational drug or use of an investigational device within 4 weeks before first study dosing.
• Have previously received immunotherapy, including immune checkpoint inhibitors, immune checkpoint agonists , immune cell therapy, and other treatments against tumor immune mechanism.
• Active autoimmune disease requiring systemic treatment within 2 years prior to initial administration, or as an autoimmune disease that can recur or for which treatment is planned determined by the investigator.
• Active or past history of definite inflammatory bowel disease (e.g., Crohn's disease or ulcerative colitis).
• History of immunodeficiency; those who test positive for HIV antibody; current chronic use of systemic corticosteroids or immunosuppressive agents.
• Known active tuberculosis (TB) (suspected of having active TB need to undergo clinical examination for exclusion of such possibility); known active syphilis infection.
• Known history of allotransplantation and allogeneic hematopoietic stem cell transplantation.
• Has known active Hepatitis B or Hepatitis C.
• Active or untreated CNS metastases.
• Subjects with peripheral neuropathy.
• Unresolved toxicity from prior anti-tumor therapy, defined as toxicity that has not recovered .
• Received a live vaccine within 30 days before the first dose or planned to receive a live vaccine during the study.
• Known allergy to any study drug component; known history of serious hypersensitivity to other monoclonal antibodies.
• Pregnant or nursing (lactating) women.

Individual anonymized participant data will be considered for sharing once the product and indication have been approved by major health authorities, if there is legal authority to share the data and there is no reasonable likelihood of participant reidentification. Data may be requested from the corresponding author.

The study protocol and SAP will be available when the main results of this study are officially published in a scientific journal.

The study protocol and SAP can be obtained by emailing to the corresponding author of the published paper.