Neoadjuvant Treatment of Cadonilimab Combined Albumin-paclitaxel, Cisplatin and Fluorouracil for Resectable Locally Advanced Esophageal Squamous Cell Carcinoma

Inclusion Criteria:

1. Participants who have given their consent and signed an informed consent form, arewilling and able to comply with the study visits, treatment, laboratory tests, andother trial procedures.
2. Patients with a pathological diagnosis of (thoracic) esophageal squamous cellcarcinoma.
3. Age between 18 and 75 years (inclusive), both male and female.
4. Locally advanced esophageal squamous cell carcinoma without suspicious cervical lymphnode metastasis and distant metastasis (cT1N1-3M0 or cT2-3N0-3M0, AJCC 8th edition).
5. Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1.
6. No prior systemic treatment for esophageal cancer (including chemotherapy, targetedtherapy, immune checkpoint inhibitors such as anti-PD-1 or PD-L1 antibodies,anti-CTLA-4 antibodies, etc.).
7. Planned surgical treatment after completion of neoadjuvant therapy.
8. Expected survival time of at least 6 months.
9. Clearly measurable lesions that meet the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.
10. Adequate organ function based on laboratory values obtained during the screeningperiod, including:

1. Hematology: no blood transfusions or blood products within 14 days, no use of G-CSF orother hematopoietic growth factors for correction, white blood cell count (WBC) ≥ 3.0 × 109/L, absolute neutrophil count (ANC) ≥ 1.5 × 109/L, platelet count (PLT) ≥ 75 × 109/L,hemoglobin (Hgb) ≥ 9 g/dL.
2. Blood chemistry: serum total bilirubin ≤ 1.5 × upper limit of normal (ULN), aspartateaminotransferase or alanine aminotransferase ≤ 2.5 × ULN (≤ 5 × ULN for patients with livermetastasis), serum creatinine ≤ 1.5 × ULN.
3. Coagulation function: prothrombin time (PT), international normalized ratio (INR) ≤ 1.5 × ULN.
4. Cardiac function: left ventricular ejection fraction (LVEF) ≥ 50%. 11. Femaleparticipants of childbearing potential must have a negative serum pregnancy test within 3days before starting study drug and agree to use a medically accepted highly effectivemethod of contraception (such as an intrauterine device, contraceptive pills, or condoms)during the study period and within 3 months after the last dose of study drug. Maleparticipants with partners of childbearing potential must have undergone surgicalsterilization or agree to use an effective method of contraception during the study periodand within 3 months after the last dose of study drug.

Exclusion Criteria:

1. History of or concurrent active malignancy other than adequately treated non-melanomaskin cancer, curatively treated in situ cancer or other malignancy with no evidence ofdisease for at least 5 years.
2. Active bleeding within 3 months; a history of arterial or venous thrombotic eventswithin 6 months, such as stroke (including transient ischemic attack), deep veinthrombosis, and pulmonary embolism; known inherited or acquired bleeding diathesis (e.g., coagulation factor deficiencies) or thrombotic disorders, such as patients withhemophilia; current or recent (within 10 days before the start of the study treatment)use of full-dose oral or parenteral anticoagulants or thrombolytic agents fortherapeutic purposes (allowed prophylactic use of low-dose aspirin andlow-molecular-weight heparin); major surgery (excluding biopsy) within 4 weeks beforestarting study drug treatment or the surgical incision has not fully healed; currentor recent (within 10 days before the start of the study treatment) use of aspirin (> 325 mg/day [maximum antiplatelet dose]) or other nonsteroidal anti-inflammatory drugs,dual antiplatelet therapy, clopidogrel, prasugrel, ticagrelor, or cilostazol.
3. The patient has received systemic treatment, surgery, or radiotherapy for esophagealcancer, including immunotherapy such as anti-PD-1 or PD-L1 antibodies, anti-CTLA-4antibodies, targeted therapy, or chemotherapy.
4. The patient has used systemic corticosteroids or other systemic immunosuppressivedrugs within 2 weeks before treatment, or is expected to use systemicimmunosuppressive drugs during the trial. The use of inhaled glucocorticoids orphysiological replacement doses of glucocorticoids is allowed.
5. The patient has active autoimmune diseases. Patients with type 1 diabetes,hypothyroidism requiring replacement therapy only, skin diseases (such as vitiligo,psoriasis, or alopecia) that do not require systemic treatment or are not expected torecur without external triggering factors can be included in the trial.
6. The patient has known active tuberculosis, is receiving anti-tuberculosis treatment,or has received anti-tuberculosis treatment within 1 year prior to the first dose.
7. The patient has severe, uncontrolled systemic diseases, such as refractoryhypertension, severe active infection, etc.
8. The patient has known human immunodeficiency virus (HIV) infection or is known to beHIV-seropositive.
9. Untreated chronic hepatitis B or active carriers of hepatitis B virus (HBV) (HBV DNA >500 IU/mL) or active carriers of HCV detectable by HCV RNA. Note: Inactive carriersof hepatitis B surface antigen (HBsAg) or stable patients with treated chronichepatitis B (HBV DNA < 500 IU/mL) can be included in the study.
10. History of interstitial lung disease, drug-induced interstitial lung disease,radiation pneumonitis, or symptomatic interstitial lung disease, or active pneumoniadetected by chest CT scan within 4 weeks prior to initial drug treatment in the study.
11. Known symptomatic, untreated, or progressively advancing central nervous system (CNS)or leptomeningeal metastases.
12. Known allergy to any investigational drug or excipient.
13. Participation in other drug clinical trials within 4 weeks before enrollment.
14. Breastfeeding women.
15. As judged by the investigator, the patient has other factors that may affect the studyresults or may cause premature termination of the study, such as alcoholism, drugabuse, other serious illnesses (including mental illness) requiring concomitanttreatment, significant laboratory abnormalities, or family or social factors that mayaffect the patient's safety.