A Phase II Clinical Study of Induction Adebrelimab Combined With Chemotherapy Followed by Concurrent Chemoradiotherapy for Locally Advanced Unresectable Esophageal Squamous Cell Carcinoma (ESCC)

Inclusion Criteria: * 1\. Age 18-75 years old, both men and women; 2. Histopathology confirmed esophageal squamous cell carcinoma, locally advanced: T1N+M0, T2-4bNxM0; 3. The surgeon assesses that surgery is not feasible or the patient refuses surgical treatment; 4. If technically feasible, all patients are recommended to have local staging determined by endoscopic ultrasound (EUS); The endoscopic examination report or gastrointestinal (GI) clinical records should clearly indicate the T and N stages; Perform PET-CT examination; 5. Except for basal or squamous cell skin cancer, bladder cancer in situ or cervical cancer, there is no history of malignant tumor within 5 years; Patients with malignant tumors who have undergone surgical treatment in the past and those who have survived disease-free for more than 5 years meet the inclusion criteria; 6. Have not received any systemic anti-tumor treatment in the past (systemic chemotherapy, radiotherapy, targeted therapy, immunotherapy, etc.) 7. At least one measurable lesion（According to RECIST 1.1：The long diameter of the measurable lesion on CT scan is ≥10 mm or the short diameter of the enlarged lymph node is ≥15 mm）; 8. ECOG: 0\~1; 9. Expected survival period ≥ 12 weeks; 10. Major organ function has to meet the following certeria: (1) Blood routine examination: 1. HB≥90g/L; 2. ANC ≥ 1.5 × 109 / L; 3. PLT ≥ 100 × 109 / L; (2) Biochemical examination: a. ALT and AST \< 2.5XULN; b. TBIL ≤ 1.5XULN; c. Cr ≤ 1.5XULN; 11. Left ventricu…