To evaluaate the efficacy and safety of the regimen incuding Penpulimab, Gemcitabine and Anlotinib in the treatment of metastatic nasopharyngeal carcinoma. Using Progression-Free-Survival as the primary endpoint.

Inclusion Criteria:

1. The participants voluntarily signed an informed consent form.
2. Age of ≥ 18 years and ≤ 75 years at the time of enrollment.
3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
4. xpected survival of ≥ 3 months.
5. Histologically or cytologically confirmed diagnosis of stage IVb NPC (AJCC 8th).
6. Metastatic NPC patients who have not recieved the first-line platinumbased chemotherapy.
7. At least one measurable tumor lesion per RECIST 1.1 criteria.
8. Adequate organ function.
9. Female participants of childbearing potential must agree to use contraception (such as intrauterine device, contraceptive pill, or condom) during the study and for 6 months after the end of the study; must have a negative serum pregnancy test within 7 days before study entry and must not be lactating. Male participants must agree to use contraception during the study and for 6 months after the end of the study.
10. The subjects are willing and able to comply with the visit schedule, treatment plan, laboratory examination, and other requirements of the study.

Exclusion Criteria:

1. ubjects 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.
2. Participation in treatment with an investigational drug or use of an investigational device within 4 weeks before first study dosing.
3. Palliative local treatment was performed for non target lesions within 2 weeks before the first administration; Received nonspecific immunomodulatory therapy (such as interleukin, interferon, thymosin, etc., excluding IL-11 for the treatment of thrombocytopenia) within 2 weeks before the first administration; Received Chinese herbal medicine or Chinese patent medicine with anti-tumor indications within 1 week before the first administration.
4. Progression during or within 6 months after receiving systemic treatment for locally advanced disease (including induction therapy, concurrent radiotherapy, adjuvant therapy) (excluding oral single agent chemotherapy maintenance).
5. Patients with local recurrence and distant metastasis after radical treatment for locally advanced disease.
6. Patients with recurrent nasopharyngeal lesions after radiotherapy and who have received secondary radiotherapy.
7. Have previously received immunotherapy, including immune checkpoint inhibitors, immune checkpoint agonists , immune cell therapy, and other treatments against tumor immune mechanism.
8. Previously received anti angiogenic therapy.
9. According to the judgment of the investigator, there are subjects with concomitant diseases that seriously endanger the safety of subjects or affect the completion of the study, or subjects who believe that there are other reasons that are not suitable for enrollment.