Cadonilimab in the Treatment of Recurrent/Metastatic Nasopharyngeal Carcinoma

Inclusion Criteria: 1. The subject must sign the written informed consent form (ICF) voluntarily； 2. Age ≥18 years and ≤65 years； 3. Subjects with histopathological diagnosis of nasopharyngeal carcinoma； 4. Primarily metastatic (stage IVB as defined by AJCC staging system for NPC, eighth edition) or recurrent/metastatic NPC that is not amenable to local regional treatment or curative treatment and at least 6 months after radical treatment； 5. Has not received prior systemic treatment; 6. Has a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Status 7. Subject must have a measurable target lesion based on RECIST v1.1; Exclusion Criteria: 1. Allergic to monoclonal antibodies, any cadonilimab components, gemcitabine, cisplatin, and other platinum drugs; 2. Prior therapy as follow: Anti-PD-1, anti-PD-L1 or anti-CTLA-4; Concurrent medical condition requiring the use of cortisol (\>10mg/day Prednisone or equivalent dose) or other systematic immunosuppressive medications within 14 days before the study treatment（Except：inhalation or topical corticosteroids）. 3. Any active malignancy ≤ 2 years before randomization except for specific cancer under investigation in this study and any locally recurring cancer that has been treated curatively (eg, resected basal or squamous cell skin cancer, superficial bladder cancer, carcinoma in situ of the cervix or breast)； 4. Female patients who are at pregnancy or lactation.