This is a randomised, double-blinded, placebo-controlled, multi-center phase III trial, comparing the efficacy and safety of SHR-1210 + paclitaxel + cisplatin vs placebo+paclitaxel +cisplatin as 1L therapy for advanced esophageal cancer patients in China. SHR-1210 is a humanized anti-PD1 IgG4 monoclonal antibody.

In this study, eligible subjects will be randomized into study arm or control arm. Treatment cycles of chemotherapy will be at most 6 cycles which would be decided by the investigators. Progression-free survival (PFS) assessed by the Independent Review Committee (IRC) and overall survival (OS) will be the primary outcomes.

Inclusion Criteria:

1. Histologically or cytologically confirmed unresectable local advanced/recurrent or metastasis esophageal squamous cell carcinoma;
2. No previous systemic anti-tumor treatment;
3. Subjects must have at least one measurable tumor lesion per RECIST 1.1;
4. Tissue samples should be provided for biomarkers (such as PD-L1) analysis;
5. ECOG: 0-1;
6. Adequate organ and bone marrow function;

Exclusion Criteria:

1. Allergic to monoclonal antibodies, any SHR-1210 components, paclitaxel, cisplatin and other platinum drugs;

2. Prior therapy as follow:

   1. Anti-PD-1 or anti-PD-L1;
   2. Any experimental drugs within 4 weeks of the first dose of study medication;
   3. Received major operations or serious injuries within 4 weeks of the first dose of study medication;
   4. Received last dose of anticancer therapy (including chemotherapy, radiotherapy, targeted therapy, etc.) within 4 weeks of the first dose of study medication;

3. Not recovered to ≤CTCAE 1 from adverse events (except for hair loss) due to a previously anti-tumor treatment;

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

5. Pregnancy or breast feeding;