This is an open label, single-arm, multi-center, phase 2 Study of SHR-1210 in recurrent/metastatic nasopharyngeal carcinoma(R/M NPC) patients who have received previous at least two lines of chemotherapy.

The primary objective of this phase 2 study is to assess objective response rate of SHR-1210 in patients with R/M NPC. The secondary objective is to observe the duration of response, progression free survival, time to response, overall survival and safety of SHR-1210 in R/M NPC. ADA is also investigated.

Inclusion Criteria:

1. Histologically confirmed Recurrent/Metastatic Nasopharyngeal Carcinoma (WHO type II-III);

2. Stage IVb R/M NPC failed from first-line platinum based chemotherapy and second-line chemotherapy;

3. ECOG performance status of 0 or 1;

4. Life expectancy ≥ 12 weeks;

5. Subjects must have measurable disease by CT or MRI per RECIST 1.1 criteria;

6. Can provide either a newly obtained or archival tumor tissue sample;

7. Adequate laboratory parameters during the screening period as evidenced by the following:

   1. Absolute neutrophil count ≥ 1.5 × 10^9/L ;
   2. Platelets ≥ 90 × 10^9/L;
   3. Hemoglobin ≥ 9.0 g/dL;
   4. Serum albumin ≥ 2.8g/dL;
   5. Total bilirubin (TBIL) ≤ 1.5 × upper limit of normal (ULN), ALT and AST ≤ 1.5×ULN
   6. Creatinine clearance≥50 mL/min;

8. Female of child bearing potential, a negative urine or serum pregnancy test result within 72 h before study treatment. Participants of reproductive potential must be willing to use adequate contraception for the course of the study through 60 days after the last dose of SHR-1210. Male subjects with WOCBP partner must be willing to use adequate contraception for the course of the study through 120 days after the last dose of SHR-1210;

9. Subjects must be willing to participate in the research and sign an informed consent form (ICF);

Exclusion Criteria:

1. Subjects with any active autoimmune disease or history of autoimmune disease;

2. Subjects having clinical symptoms of metastases to central nervous system (such as cerebral edema, requiring steroids intervention, or brain metastasis progression);

3. Has a known additional malignancy within the last 5 years before study treatment with the exception of curatively treated basal cell and squamous cell carcinoma of the skin and/or curatively resected in-situ cervical and/or breast cancers;

4. Uncontrolled clinically significant heart disease, including but not limited to the following: (1) > NYHA II congestive heart failure; (2) unstable angina, (3) myocardial infarction within the past 1 year; (4) clinically significant supraventricular arrhythmia or ventricular arrhythmia requirement for treatment or intervention;

5. 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. Doses > 10 mg/day prednisone or equivalent for replacement therapy;

6. Has received prior anti-cancer monoclonal antibody (mAb), chemotherapy, targeted small molecule therapy within 4 weeks prior to first dosing or not recovered to ≤CTCAE 1 from adverse events (except for hair loss or neurotoxic sequelae from prior platinum therapy) due to a previously administered agent. Palliative irradiation should be ended 2 weeks before first dosing;

7. Active infection or an unexplained fever > 38.5°C before two weeks of first dosing (subjects with tumor fever may be enrolled at the discretion of the investigator);

8. Known Human Immunodeficiency Virus (HIV) infection、active Hepatitis B or Hepatitis C;

9. Currently participating or has participated in a study within 4 weeks of the first dose of study medication;

10. Received a live vaccine within 4 weeks of the first dose of study medication. Pregnancy or breast feeding;

11. Received a systematic antibiotics within 4 weeks of the first dose of study medication.

    Pregnancy or breast feeding.

12. Prior therapy with a PD-1, anti-PD-Ligand 1 (PD-L1) or CTLA-4 agent;

13. Subjects are known to have a history of psychiatric substance abuse, alcoholism, or drug addiction;

14. Pregnancy or breast feeding;

15. According to the investigator, other conditions that may lead to stop the research.

AEs should be reported from the time the participant has taken at least 1 dose of study treatment through the participant's last visit (approximately 3 years).

Same event may appear as both an adverse event (AE) and serious adverse event (SAE). However, what is presented are distinct events. An event may be categorized as serious in one participant and as non-serious in another, or a participant may have experienced both a serious and non-serious event.