A Study of Bemosubaiabimab Combined With Anlotinib and Radiotherapy and Chemotherapy for the Treatment of Oligometastatic Esophageal Cancer

Inclusion Criteria: * Voluntarily participated in this study and signed the informed consent form, with good compliance and cooperation during the follow-up; * Male or female aged 18 years or above; * Patients diagnosed with oligometastatic esophageal squamous cell carcinoma through imaging. Oligometastatic esophageal cancer is defined as having no more than 5 metastatic lesions other than the primary tumor at the initial diagnosis or during treatment, and the metastatic lesions involve no more than 2 distant organs, and the disease duration is more than 3 months; * At least one measurable lesion according to the RECIST 1.1 standard; * Expected lifespan of at least 3 months; * ECOG (Eastern Cooperative Oncology Group) score: 0-1 point; * Adequate organ and bone marrow functions; * For fertile women, appropriate contraceptive measures must be taken from the screening to 3 months after stopping the study treatment, and must be non-lactating subjects. Before starting the medication, the pregnancy test should be negative. For men, they must agree to use appropriate methods of contraception during the trial and for 8 weeks after the last administration of the trial drug or have undergone surgical sterilization. Exclusion Criteria: * Have received PD-1/PD-L1/CTLA-4 antibody or anti-angiogenic drugs (such as sunitinib, sorafenib, regorafenib, bevacizumab, imatinib, apatinib, etc.) in the past; * Have participated in other drug clinical trials within the past 4 weeks or received systematic anti-tumor chemotherapy, radiotherapy or other anti-tumor treatments; * Patients with a high bleeding tendency; * Have received organ transplantation in the past; * Have other inoperable conditions; * Subjects with any severe and/or uncontrolled diseases, including: m) Patients with hypertension who cannot achieve good control with a single antihypertensive drug (systolic blood pressure ≥ 150 mmHg, diastolic blood pressure ≥ 100 mmHg); or using two or more antihypertensive drugs to control blood pressure; n) Patients with grade II or above myocardial ischemia or myocardial infarction, arrhythmia (including QTc, male ≥ 450 ms; female ≥ 470 ms) and ≥ 2 grade congestive heart failure (New York Heart Association (NYHA) classification); o) Active or uncontrolled severe infection (NCI-CTC AE grade ≥ 2 infection); p) Liver cirrhosis, decompensated liver disease, active hepatitis or chronic hepatitis (hepatitis virus load \> 1000 IU/ml) requiring antiviral treatment; q) Renal failure requiring hemodialysis or peritoneal dialysis; r) Have a history of immunodeficiency disease, including HIV positive or having other acquired or congenital immune deficiency diseases, or having a history of organ transplantation; s) Have a history of non-infectious pneumonia requiring systemic glucocorticoid treatment or current non-infectious pneumonia/interstitial lung disease; t) Diabetic subjects with poor blood sugar control (fasting blood glucose (FBG) \> 10 mmol/L); u) Urine protein ≥ ++ and confirmed 24-hour urine protein quantification \> 1.0 g; v) Abnormal coagulation function (INR \> 1.5 or prothrombin time (PT) \> ULN + 4 seconds or APTT \> 1.5 ULN), with bleeding tendency or undergoing thrombolysis or anticoagulation treatment; Note: As long as the international normalized ratio (INR) of the drug activity is ≤ 1.5 within 14 days before starting the study treatment, it is allowed to use a small dose of heparin (i.e., enoxaparin 40 mg/day) or a small dose of aspirin (daily dosage ≤ 100 mg) for preventive purposes; w) Have any unrelieved toxic reaction higher than NCI-CTC AE grade 1 caused by previous treatment, or have not fully recovered from previous surgery; x) Have subjects with epileptic seizures and need for treatment; * Subjects who need to use corticosteroids (\> 10 mg/day prednisone equivalent dose) or other immunosuppressive drugs for systemic treatment within 7 days before the administration of the study drug. Excluded: d) If there is no active autoimmune disease, inhalation or local use of corticosteroids and doses exceeding the efficacy dose of prednisone \> 10 mg/day are allowed. e) Physiological doses of systemic corticosteroids do not exceed 10 mg/day prednisone or other corticosteroids with equivalent doses. f) Corticosteroids as preventive medication for hypersensitivity reactions (such as before CT examination); * Subjects who received live vaccines or attenuated vaccines within 30 days before the first administration of the study drug, or plan to receive live vaccines or attenuated vaccines during the study; * Have multiple factors affecting oral drugs (such as inability to swallow, chronic diarrhea, etc.); * Have a history of substance abuse of psychotropic drugs and cannot quit or have mental disorders; * Have a history of severe hypersensitivity reaction to other monoclonal antibodies; * Had experienced severe allergic reactions to anlotinib hydrochloride, bemosubaymab and/or the excipients in the investigational drugs; * According to the investigator's judgment, had accompanying diseases that seriously endangered the safety of the subjects or affected their ability to complete the study.