Immune Indicator Model for Predicting Efficacy of PD-1 Monoclonal Antibody

Inclusion Criteria:

• Patients with metastatic advanced esophageal squamous cell carcinoma (stage IV)confirmed by histology or cytology who are ready to receive PD-1 monoclonal antibodycombined with TP chemotherapy regimen.
• Eastern Cooperative Oncology Group (ECOG) performance status score between 0 and 2.
• Have measurable lesions.
• Expected survival > 3 months.
• Subjects who have received anti-tumor therapy in the past should be enrolled after thetoxicity of the previous treatment has returned to the baseline level (except forresidual hair loss effects) or CTCAE v4.03 scale score ≤ 1.
• Female or male subjects of reproductive age and their partners should agree to useeffective contraception from the time of signing the ICF until 6 months after the lastdose of study drug.
• Absolute neutrophil count (ANC) ≥1.5×109/L, platelets ≥100×109/L, hemoglobin ≥9 g/dL.Liver: Bilirubin ≤1.5 times the upper limit of normal, alkaline phosphatase (AP) ,Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3.0 times theupper limit of normal (AP, AST, ALT ≤5 times the upper limit of normal are allowed ifthere is liver metastases) Renal: Calculated creatinine clearance ≥45 mL/min.

Exclusion Criteria:

• Have active, or have had an autoimmune disease that is likely to recur (eg, systemiclupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, autoimmunethyroid disease, vasculitis, psoriasis, etc.) or at risk (e.g., organ transplantrecipients requiring immunosuppressive therapy).
• Subjects who need to receive glucocorticoid (prednisone > 10 mg/day or equivalent doseof other similar drugs) or other immunosuppressive therapy due to certain conditionswithin 14 days prior to study drug administration.
• Major surgery, or radical radiation therapy, or palliative radiation therapy withinthe previous 14 days, or radiopharmaceuticals (strontium, samarium, etc.) within 56days before starting study treatment.
• Received systemic anti-tumor therapy, including immunotherapy, biological therapy (tumor vaccines, cytokines, or growth factors to control cancer), etc. 14 days beforestarting study treatment.
• Have suffered from interstitial lung disease, chemical pneumonia, hypersensitivitypneumonitis, connective tissue disease pneumonia, pulmonary fibrosis, acute lungdisease, etc. (except for local interstitial pneumonia induced by radiotherapy), oruncontrolled systemic disease, including diabetes and hypertension.
• Patients with human immunodeficiency virus (HIV) infection.
• patients with active pulmonary tuberculosis.
• Any active infection requiring systemic therapy by intravenous infusion within 2 weeksprior to the first dose of study drug.
• People who have received a solid organ transplant.
• Patients who have received any antibody/drug (including anti-programmed death-1 (PD-1), PD-L1, etc.) targeting T-cell co-regulatory proteins (immune checkpoints).