This study is a prospective, exploratory clinical study aimed at evaluating the feasibility and safety of camrelizumab combined with synchronous chemoradiotherapy as an organ-preserving strategy for locally advanced resectable esophageal squamous cell carcinoma.

The study targets patients with locally advanced resectable stage II/III/IVa (cT1b-4aN0-3M0) ESCC. A total of 164 subjects are expected to be enrolled.

The study is a randomized, non-controlled, open-label trial. Subjects meeting the inclusion criteria will be randomly assigned in a 1:1 ratio to receive either camrelizumab combined with radiotherapy, albumin-bound paclitaxel, and carboplatin treatment (Cohort 1) or camrelizumab combined with radiotherapy and capecitabine treatment (Cohort 2).

The screening period for the study is 28 days. After completing screening examinations and assessments, eligible subjects will be randomly assigned to the following treatment regimens.

Cohort 1:

• Camrelizumab: 200 mg on Day 1, every 3 weeks
• Radiotherapy: 50-50.4 Gy / 25-28 fractions, Days 1-5, once a week
• Albumin-bound paclitaxel: IV infusion, 60-80 mg/m², Day 1, weekly
• Carboplatin: IV infusion, AUC=1-1.5, Day 1, weekly

Each cycle lasts 3 weeks, with 2-4 cycles of medication.

Efficacy evaluation (imaging and endoscopic examination) will be conducted within 6 weeks after the completion of treatment. If the efficacy evaluation indicates cCR, subjects will enter Group A1 and receive camrelizumab maintenance therapy (maximum 1 year). If the efficacy evaluation does not reach cCR, after consultation between the investigator and the subject, they will enter Group B1 to undergo radical surgery, followed by camrelizumab monotherapy maintenance treatment (maximum 1 year).

Cohort 2:

Camrelizumab: ivgtt, 200 mg, D1, Q3W Radiotherapy: 50-50.4 Gy / 25-28 fractions, D1-D5, QW Capecitabine: p.o. 625 mg/m², BID, D1-D14, Q3W; One cycle lasts 3 weeks, with 2-4 cycles of medication. Efficacy evaluation (imaging and endoscopy) will be conducted within 6 weeks after treatment completion. If the efficacy is assessed as cCR, the patient will enter Group A2: receive camrelizumab maintenance therapy (up to 1 year); if efficacy is not cCR, the patient will enter Group B2: undergo radical surgery, followed by camrelizumab monotherapy maintenance (up to 1 year).

This study will follow up subjects for disease recurrence and disease-free survival for at least 2 years. After all subjects complete the treatment/termination visit, efficacy will be evaluated.

Inclusion Criteria:

• 1. Age ≥18 years old; 2. Histologically or cytologically confirmed esophageal squamous cell carcinoma (ESCC); 3. Patients with locally advanced resectable stage II/III/IVa (cT1b-4aN0-3M0) ESCC; 4. Have not received chemotherapy, radiotherapy, or surgical treatment for esophageal cancer; 6. ECOG performance status: 0-1; 7. Expected survival ≥12 weeks; 8. Within 7 days prior to enrollment, the participant's blood routine and biochemical indicators meet the following criteria:

  1. Hemoglobin ≥90 g/L; absolute neutrophil count (ANC) ≥1.5 × 10^9/L; platelets ≥100 × 10^9/L (patients must not have received blood transfusion or growth factor support within 14 days before blood sampling);

  2. ALT and AST ≤2.5 times the upper limit of normal (ULN); ALP ≤2.5 times ULN;

  3. Total serum bilirubin <1.5 times ULN (patients with Gilbert's syndrome may enroll if total bilirubin <3 times ULN);

  4. Serum creatinine <1.5 times ULN or estimated glomerular filtration rate ≥60 ml/min/1.73 m²;

  5. Serum albumin ≥30 g/L;

  6. International normalized ratio (INR) or prothrombin time (PT) ≤1.5 times ULN, unless the patient is on anticoagulant therapy and PT value is within the expected therapeutic range;

  7. Activated partial thromboplastin time (APTT) ≤1.5 times ULN. 9. Doppler ultrasound assessment: Left ventricular ejection fraction (LVEF) ≥ lower limit of normal (50%).

     10. Women of childbearing potential must agree to use contraceptive measures (such as intrauterine device, contraceptive pills, or condoms) during the study and for 6 months after the study; must have a negative serum or urine pregnancy test within 7 days prior to study enrollment, and must not be breastfeeding; men must agree to use contraceptive measures during the study and for 6 months after the study.

     11. No severe comorbidities that would result in a life expectancy of less than 5 years.

     12. Subjects voluntarily participate in this study, sign the informed consent form, have good compliance, and cooperate with follow-up.

     Exclusion Criteria:

• 1. Individuals allergic to the treatment drugs; 2. History of organ transplantation (including autologous bone marrow transplantation and peripheral stem cell transplantation); 3. Active or uncontrolled severe infection (≥ CTCAE5.0 grade 2 infection), including but not limited to hospitalization due to infection complications, bacteremia, or severe pneumonia, or unexplained fever >38.5°C before the first administration; 4. Individuals with a history of mental drug abuse who cannot quit or have psychiatric disorders; 5. Subjects who have had or currently have other malignancies requiring active treatment within the past 5 years (fully treated cases with an expected 5-year survival >90%, such as basal cell or squamous cell skin cancer, cervical carcinoma in situ, or breast carcinoma in situ, are excluded from this restriction); 6. Uncorrectable coagulation disorders; 7. Clinically significant cardiovascular diseases, including but not limited to acute myocardial infarction, severe/unstable angina, or coronary artery bypass surgery within 6 months prior to enrollment; congestive heart failure NYHA class ≥2; ventricular arrhythmias requiring drug treatment (including QTc interval ≥450 ms for men, ≥470 ms for women); left ventricular ejection fraction (LVEF) <50%; 8. Severe liver disease (such as cirrhosis), kidney disease, respiratory system disease, uncontrolled diabetes, or other types of systemic diseases; 9. Patients whose imaging shows the tumor has invaded major blood vessels, or for whom the investigator judges that the tumor is highly likely to invade major blood vessels during the study period and cause fatal bleeding; 10. Presence of active autoimmune disease or immunodeficiency, or the following history, including but not limited to: autoimmune hepatitis, interstitial pneumonia, uveitis, rheumatoid arthritis, inflammatory bowel disease, hypophysitis, vasculitis, nephritis, etc. The following exceptions apply: patients with a history of autoimmune hypothyroidism who are receiving thyroid hormone replacement therapy may be enrolled. Patients with type 1 diabetes whose blood glucose is controlled after insulin therapy may participate in this study.

  11. Patients who are using immunosuppressive agents or systemic corticosteroid therapy for immunosuppression purposes (dose >10 mg/day of prednisone or other equivalent steroids, and continued use within 2 weeks prior to enrollment); 14. Underwent surgery within 28 days before enrollment in this study (excluding biopsy) or whose surgical incision has not fully healed; 15. Received any other investigational drug treatment or participated in other interventional studies within 4 weeks prior to signing the informed consent; 16. Pregnant women (positive pregnancy test before taking the drug) or women who are breastfeeding; 17. Patients deemed unsuitable for enrollment based on the investigator's judgment.