Radiotherapy Combined With PD-1 Monoclonal Antibody and Capecitabine in the Treatment of Nasopharyngeal Carcinoma

Inclusion Criteria:

1. The patient was histologically or cytologically diagnosed with nasopharyngealcarcinoma;
2. The patient was newly diagnosed with metastatic nasopharyngeal carcinoma (AJCC eighthedition), and after 4-6 cycles of gemcitabine plus cisplatin combined with PD-1monoclonal antibody regimen, the efficacy reached more than stable disease;
3. Except for the primary tumor and cervical lymph node metastasis, less than 5 distantorgan metastases, and were suitable for SBRT radiotherapy;
4. ECOG PS score 0-2 points;
5. Aged 18-70 years old;
6. Major organ function met the following criteria (14 do not allow the use of any bloodcomponents and cell growth factor):
7. Neutrophil ANC ≥ 2.0 × 10^9/L; platelet count PLT ≥ 100 × 10^9/L; hemoglobin HB ≥ 90 g/L;
8. Serum albumin ≥ 28 g/L;
9. Alanine aminotransferase ALT, aspartate aminotransferase AST ≤ 2.5 × ULN; ifthere is liver metastasis, ALT and AST ≤ 5 × ULN;
10. Serum creatinine ≤ 1.5 × ULN, Or creatinine clearance ≥ 60 mL/min;
11. INR ≤ 1.5 × ULN, and APTT ≤ 1.5 × ULN;
12. Life expectancy ≥ 12 weeks;
13. The subject who voluntarily joins the study, sign informed consent, and coordinateswith follow-up.

Exclusion Criteria:

1. Recurrent and metastatic nasopharyngeal carcinoma after initial treatment;
2. Patients received previous treatment of primary lesion or metastasis except for thestandard first-line regimen (gemcitabine plus cisplatin combined with PD-1 monoclonalantibody regimen), including induction chemotherapy, adjuvant chemotherapy, concurrentchemoradiotherapy, surgery and other treatments;
3. Central nervous system metastastic (confirmed or suspected);
4. Allergy to PD-1 monoclonal antibody or other PD-1 monoantibody; intolerance or allergyto capecitabine; suffering any disease or extrinsic factors affecting oral drugs;
5. Uncontrolled cardiac clinical symptoms or diseases, such as: ① heart failure of NYHAGrade II or higher ; ② unstable angina pectoris; ③ suffering myocardial infarctionwithin 1 year; ④ patients with supraventricular or arrhythmia requiring clinicalintervention;
6. Severe infection (CTCAE 5.0 ≥ 2) 4 weeks before the first use of study drugs, such assevere pneumonia, bacteremia, infectious complications requiring hospitalization;baseline chest imaging examination suggests the presence of active pulmonaryinflammation; symptoms and signs of infection or the need for oral or intravenousantibiotics (excluding the prophylactic use of antibiotics) 2 weeks before the firstuse of the study drug;
7. History of other malignancies within 5 years or at the time,but except for curedcutaneous basal cell carcinoma and cervical carcinoma in situ, breast carcinoma insitu, superficial bladder tumors (Ta, Tis and T1) and papillary thyroid cancer as wellas other cancers treated more than 3 years before the start of the study;
8. Any of the following conditions is met:
9. Received any investigational drug before the first use of the study drug;
10. Participated in another clinical study at the same time, unless it is anobservational (non-interventional) clinical study or interventional clinicalstudy at the follow-up time;
11. Required systemic treatments with corticosteroids (the dose higher than theequivalent dose of 10 mg prednisone per day) or other immunosuppressive agents 2weeks before the first use of the study drug, except for local inflammation andprevention of allergy and nausea and vomiting. In the absence of activeautoimmune disease, inhaled or topical steroids and adrenocorticotropic hormonereplacement at doses greater than 10 mg daily in prednisone efficacy dose areallowed;
12. Received anti-tumor vaccines or vaccinated live vaccines 4 weeks before the firstdose of study drug;
13. Underwent excessive surgery or severe trauma 4 weeks before the first use ofstudy drug;
14. Patients had active autoimmune diseases and a history of autoimmune diseases (such asinterstitial pneumonia, colitis, hepatitis, hypophysitis, vasculitis, nephritis,hyperthyroidism, hypothyroidism, including but not limited to these diseases andsyndromes) in the past 2 years; patients who did not require any intervention afteradulthood are allowed;
15. History of immunodeficiency, including HIV positive, or other acquired, congenitalimmunodeficiency diseases, or history of organ transplantation and bone marrowtransplantation;
16. Patients with active pulmonary tuberculosis infection found by medical history or CTexamination, or with a history of active pulmonary tuberculosis infection within 1year before enrollment, or with a history of active pulmonary tuberculosis infection 1year ago but without regular treatment;
17. Patients with active hepatitis (HBV ≥ 2000 IU/ml or HBV DNA ≥ 10000/ml), or hepatitisC (hepatitis C antibody positive, and HCV-RNA ≥ 1000/ml);
18. Patients with coagulation abnormalities (PT > 16s, APTT > 43s, TT > 21s, Fbg < 2 g/L),bleeding tendency or receiving thrombolytic or anticoagulant therapy; or patients withprevious severe bleeding (bleeding > 30ml within 3 months), hemoptysis (bleeding > 5mlwithin 4 weeks) within 12 months due to thromboembolic events (including stroke eventsand/or transient ischemic attack);
19. Uncontrolled hypertension (systolic blood pressure > 140 mmHg, or diastolic bloodpressure > 90 mmHg); coronary heart disease, arrhythmia ≥ grade II (including QTcprolongation, male > 450 ms, female > 470 ms) and heart failure;
20. Urine protein ≥ + +, or 24 hour urine protein ≥ 1.0 g;
21. Current diarrhea-related diseases (e.g., ulcerative colitis, Crohn's disease, chronicdiarrhea, etc.);
22. Known history of psychotropic drug abuse, alcoholism and drug abuse; or currenthistory of antiepileptic drug use;
23. Pregnant or lactating;
24. Patients considered unsuitable for inclusion by the investigator as assessed by theinvestigator.