Fluzoparib and Camrelizumab in Treating Patients With R/M NPC That Progressed After First-line Chemotherapy

Inclusion Criteria: 1. Sign an informed consent; 2. Age older than 18 years old and younger than 75 years old; 3. Patients with histologically confirmed recurrent/metastatic nasopharyngeal carcinoma, that progressed after at least first-line chemotherapy, according to RECIST 1.1 criteria; 4. No previous treatment of PD-1/L1 inhibitors, CTLA-4 inhibitors, other checkpoint inhibitors or immune modulation therapy, or PARP inhibitors; 5. At least one lesion that fulfills the criteria of "Evaluable Disease" per RECIST 1.1 Criteria; 6. Anticipated overall survival more than 3 months; 7. Satisfactory performance status: ECOG (Eastern Cooperative Oncology Group) scale 0-2; 8. Normal organ function; 9. HBV DNA\<500 IU/mL（or 2500 copies/mL）and HCV RNA negative ; 10. Male and no pregnant female, able to adapt birth control methods during treatment. Exclusion Criteria: 1. Hypersensitivity to Fluzoparib or Camrelizumab; 2. Symptomatic spinal cord compression, or high-risk to develop pathological fracture that requires urgent surgery or radiation; 3. Necrotic disease, high-risk of massive bleeding; 4. Suffered from malignant tumors, except cervical carcinoma in situ, papillary thyroid carcinoma, or skin cancer (non- melanoma) within five years; 5. Severe, uncontrolled heart disease, such as more than NYHA II heart failure, unstable angina pectoris, myocardial infarction within 1 year prior to signing inform consent, severe arrhythmia that requires urgent intervention; 6. Previous treatment of PD-1/L1 inhibitors, CTLA-4 inhibitors, other checkpoint inhibitors or immune modulation therapy, or PARP inhibitors; 7. Receive vaccine or live vaccine within 28 days prior to signing the informed consent; 8. Still suffered from adverse effect (more than CTCAE grade 1), that results from previous treatment; 9. Severe, uncontrolled infections within 28 days prior to signing inform consent; 10. Active, known or suspected autoimmune disease; Type I Diabetes, hypothyroidism those only need hormone replacement therapy, vitiligo or inactive asthma who don't need systemic therapy can recruit; 11. HIV positive; 12. Diagnosed as active pulmonary tuberculosis within one year before signing inform consent; or diagnosed as active pulmonary tuberculosis more than one year, but did not receive standardized anti-tuberculosis treatment; 13. Hepatitis B surface antigen (HBsAg) positive and HBV-DNA ≥500IU/ml, or 2500cps/ml; Positive HCV RNA; 14. History of drug abuse, drug taking, alcohol abuse; 15. Other diseases which may influence the safety or compliance of the clinical trial, such as mental illness, or their family and society factors; 16. Women of child-bearing potential who are pregnant or breastfeeding.