SHR-1210 in Combination With Anlotinib in Patients With Advanced or Metastatic Esophageal Squamous Cell Cancer

Inclusion Criteria: 1. Age:18 years to 75 years, male or female. 2. Histologically or cytologically confirmed squamous cell carcinoma of the esophagus, locally advanced, unresectable, recurrent or metastatic disease. 3. Progressed after first-line chemotherapy. 4. Measurable disease based on Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 5. Newly acquired or archived tumor tissue samples can be obtained. 6. Eastern Collaborative Oncology Group (ECOG) Performance Status ≤ 1 7. Life expectancy \>12 weeks. 8. Adequate organ function. 9. For females of child bearing potential, a negative urine or serum pregnancy test result within 1 week before study treatment. Participants of reproductive potential must be willing to use adequate contraception for the course of the study until 4 months after the last dose of any of the drugs in the study. 10. Willing and able to follow the study protocol and follow-up procedures for treatment and follow-up. 11. Willing and able to provide written informed consent. Exclusion Criteria: Patients should not be selected for this clinical study if they have any of the following conditions: 1. Abnormal coagulation function , with bleeding tendency or receiving thrombolytic or anticoagulant therapy. Note: Low-dose heparin (60,000-12,000 U/day for adults) or low-dose aspirin (≤100mg/day) are permitted for prophylactic purposes if INR≤1.5. 2. The arterial/venous thrombosis events, such as cerebrovascular accidents (including transient ischemic attack, cerebral hemorrhage, cerebral infarction), deep venous thrombosis, pulmonary embolism, etc, occurred within 6 months before administration. 3. Clinically significant hemoptysis occurred within 3 months before medication (hemoptysis \> 50ml per day); Or clinically significant bleeding symptoms or definite bleeding tendency, such as gastrointestinal bleeding, bleeding gastric ulcer, baseline fecal occult blood ++ or above, or vasculitis, etc. 4. Subjects with any active, known or suspected autoimmune disease or history of autoimmune disease. 5. Received systemic steroid therapy within 3 days of the first dose of study medication. 6. Received a live vaccine within 4 weeks of the first dose of study medication. 7. Major surgery received or severe traumatic injury, fracture, or ulcer occurred within 4 weeks of the first dose of study medication. 8. Imaging (CT or MRI) showed that the distance of the tumor lesion from great vessels was less than 5 mm, or invasion of local great vessels, or central tumor with high blood risk; Or there is obvious lung cavity or necrotizing tumor. Uncontrolled clinically significant systemic diseases, including active infection, unstable angina, angina occurred within 3 months,≥ NYHA II congestive heart failure, myocardial infarction occurred within 6 months, severe arrhythmia, liver, kidney, or metabolic disease. 9. Pregnant or lactating female. 10. Participate in other clinical trials currently or within 4 weeks prior to enrollment. 11. Receiving other anti-cancer drugs (including anti-cancer traditional chinese medicine). 12. Familial, sociological or geographical conditions that, in the clinical judgment of the Principal Investigator, do not permit compliance with the protocol.