Apatinib and Camrelizumab in Recurrent or Metastatic Nasopharyngeal Carcinoma With First-line Treatment Failure

Inclusion Criteria: 1. Male or female; 18-70 years of age. 2. Subjects diagnosed with pathological confirmed metastatic nasopharyngeal carcinoma, or subjects with recurrent NPC that is unfit for local treatment 3. Underwent at least first-line treatment failure 4. ECOG performance status of 0 or 1. 5. Life expectancy more than 12 weeks. 6. Subjects enrolled must have measurable lesion(s) according to response evaluation criteria in solid (RECIST) v1.1. 7. Adequate organ function assessed by laboratory parameters during the screening period. 8. Female subjects agree not to be pregnant or lactating from beginning of the study screening through at least 3 months after receiving the last dose of study treatment. Both men and women of reproductive potential must be willing and able to employ a highly effective method of birth control/contraception to prevent pregnancy. 9. Able to understand and sign an informed consent form (ICF). Exclusion Criteria: 1. Subjects with any active autoimmune disease or history of autoimmune disease, or history of syndrome that requires systemic steroids or immunosuppressive medications, including but not limited to the following: rheumatoid arthritis, pneumonitis, colitis (inflammatory bowel disease), hepatitis, hypophysitis, nephritis, hyperthyroidism, and hypothyroidism, except for subjects with vitiligo or resolved childhood asthma/atopy. Subjects with the following conditions will not be excluded from this study: asthma that requires intermittent use of bronchodilators, hypothyroidism stable on hormone replacement, vitiligo, Graves' disease, or Hashimoto's disease. Additional exceptions may be made with medical monitor approval; 2. Known history of hypersensitivity to any components of the Camrelizumab formulation or other monoclonal antibodies ; 3. Concurrent medical condition requiring the use of immunosuppressive medications, or immunosuppressive doses of systemic or absorbable topical corticosteroids. Doses 10 mg/day prednisone or equivalent are prohibited within 4 weeks before study drug administration. Note: corticosteroids used for the purpose of IV contrast allergy prophylaxis are allowed; 4. Subjects who underwent anti-PD-1 /PD-L antibody or anti-CTLA-4 antibody (or any other antibody acting on T cell synergistic stimulation or checkpoint pathway) and anti-angiogenic drugs. 5. Abnormal coagulation function (INR\>1.5×ULN, APTT\>1.5×ULN) with bleeding tendency. 6. The laboratory test values within 7 days before enrollment do not meet the relevant standards. 7. Active central nervous system (CNS) metastases (indicated by clinical symptoms, cerebral edema, steroid requirement, or progressive disease); 8. Diagnosed with other malignant tumors. 9. Uncontrolled clinically significant medical condition, including but not limited to the following: 1. Hypertension that cannot be reduced to the normal range after antihypertensive drug 2. congestive heart failure (New York Health Authority Class \> 2), 3. unstable angina, 4. myocardial infarction within the past 12 months, 5. clinically significant supraventricular arrhythmia or ventricular arrhythmia requiring treatment or intervention; 10. Active bleeding, ulcer, intestinal perforation, major surgery in the previous month; Patients with tumors close to the internal carotid artery or other large vessels, thus at risk of massive bleeding 11. Active infection or an unexplained fever; 38.5°C during screening visits or on the first scheduled day of dosing (at the discretion of the investigator, subjects with tumor fever may be enrolled); 12. History of immunodeficiency including seropositivity for human immunodeficiency virus (HIV), or other acquired or congenital immune-deficient disease; active tuberculosis (TB), anti-TB treatment is ongoing or within 1 year prior to screening; Evidence of hepatitis B virus (HBV) or hepatitis C virus (HCV) infection or risk of reactivation based on institutional guidelines and tests. Testing may include the following: HBV DNA, HCV RNA, hepatitis B surface antigen, or anti-Hepatitis B core antibody. 13. Received any anti-infective vaccine (e.g. influenza vaccine, varicella vaccine, etc.) within 4 weeks prior to enrollment. 14. Any other medical (eg, pulmonary, metabolic, congenital, endocrinal, or CNS disease), psychiatric, or social condition deemed by the investigator to be likely to interfere with a subject's rights, safety, welfare, or ability to sign informed consent, cooperate, and participate in the study or would interfere with the interpretation of the results;