Neoadjuvant chemoradiotherapy (CRT) followed by surgery has become the standard treatment option for locally advanced esophageal cancer (EC). However, only 20% to 40% of EC patients can achieve pathologic complete response (pCR) after neoadjuvant CRT with favorable prognosis. Immunotherapy targeting the PD-1/PD-L1 checkpoints has demonstrated promising activity in advanced EC. The aim of this study was to evaluate the efficacy and safety of the combination of toripalimab (an anti-PD-1 antibody) combined with neoadjuvant CRT in locally advanced esophageal squamous cell carcinoma (ESCC).

Inclusion Criteria:

1. A histopathological diagnosis of resectable thoracic esophageal squamous cell carcinoma with a pre-treatment clinical stage of T1-4aN1-3M0 or T3-4aN0M0 according to the 8th edition of the UICC staging system;
2. Patients who are anti-tumor treatment-naive;
3. Estimated life expectancy >6 months
4. Aged 18 to 70 years old of either gender
5. The function of important organs meets the following requirements: a. white blood cell count (WBC) ≥ 4.0×109/L, absolute neutrophil count (ANC) ≥ 1.5×109/L; b. platelets ≥ 100×109/L; c. hemoglobin ≥ 9g/dL; d. serum albumin ≥ 2.8g/dL; e. total bilirubin ≤ 1.5×ULN, ALT, AST and/or AKP ≤ 2.5×ULN; f. serum creatinine ≤ 1.5×ULN or creatinine clearance rate >60 mL/min;
6. PS score of 0-1;
7. Ability to understand the study and sign informed consent.

Exclusion Criteria:

1. Patients who have been treated previously with anti-tumor therapy (including chemotherapy, radiotherapy, surgery, immunotherapy, etc.);
2. Known or suspected allergy or hypersensitivity to monoclonal antibodies, any ingredients of Toripalimab, and the chemotherapeutic drugs paclitaxel or cisplatin;
3. Patients who have a preexisting or coexisting bleeding disorder;
4. Other uncontrollable inoperable patients;
5. Female patients who are pregnant or lactating;
6. Inability to provide informed consent due to psychological, familial, social and other factors;
7. Presence of CTC grade ≥ 3 peripheral neuropathy;
8. A history of malignancies other than esophageal cancer before enrollment, excluding non-melanoma skin cancer, in situ cervical cancer, or cured early prostate cancer
9. A history of diabetes for more than 10 years and poorly controlled blood glucose levels;
10. Patients who cannot tolerate chemoradiotherapy or surgery due to severe cardiac, lung, liver or kidney dysfunction, or hematopoietic disease or cachexia.
11. Active autoimmune diseases, a history of autoimmune diseases (including but not limited to these diseases or syndromes, such as colitis, hepatitis, hyperthyroidism), a history of immunodeficiency (including a positive HIV test result), or other acquired or congenital immunodeficiency diseases, a history of organ transplantation or allogeneic bone marrow transplantation;
12. A history of interstitial lung disease or non-infectious pneumonia;
13. A history of active pulmonary tuberculosis infection within 1 year or a history of active pulmonary tuberculosis infection more than 1 year ago but without formal anti-tuberculosis treatment;
14. Presence of active hepatitis B (HBV DNA ≥ 2000 IU/mL or 104 copies/mL), hepatitis C (positive for hepatitis C antibody, and HCV-RNA levels higher than the lower limit of the assay).