Anlotinib Plus Etoposide and Carboplatin as First-line Treatment for Extensive-stage Small Cell Lung Cancer

Inclusion Criteria: 1. According to the 8th edition of the AJCC/UICC TNM staging system for NSCLC, patients with extensive stage SCLC confirmed by histology or cytology and are confirmed to have at least one measurable lesion according to RECIST 1.1. 2. Without active brain metastasis 3. Previously treated with ICIs with progressive disease. 4. Age ≥18 years and ≤75 years; 5. ECOG PS score: 0 to 1 6. The main organs function is normal, that is, the following criteria met: good hematopoietic function, defined as absolute neutrophil count ≥1.5×109 /L, platelet count≥100 ×109 /L, hemoglobin ≥90g/L \[no blood transfusion or no erythropoietin (EPO) dependence within 7 days before enrollment\]; biochemical test results should meet the following criteria: BIL \< 1.25 times the upper limit of normal value (ULN); ALT and AST \< 2.5 × ULN; in case of liver metastases, ALT and AST \< 5 × ULN; Cr ≤1.5×ULN or creatinine clearance (CCr) ≥60ml/min; Coagulation function is good, INR and PT ≤1.5 times ULN; if the subject is receiving anticoagulant treatment, PT should be within the prescribed range of use of anticoagulant drugs; 7. Women of child-bearing age should agree to take contraceptive measures (such as intrauterine devices, contraceptives or condoms) during the study and within 6 months after the study; non-breast-feeding patients whose serum or urinary pregnancy test should be negative; male patients should agree to take contraceptive measures during the study and within 6 months after the study. 8. Patients are voluntarily enrolled into the study, sign the informed consent form and have good compliance. Exclusion Criteria: 1. Subjects with active CNS metastases are excluded. 2. Non-small cell lung cancer. 3. With obvious hemorrhage symptom 4. Patients with many factors affecting oral medication, such as dysphagia, gastrointestinal resection, chronic diarrhea and intestinal obstruction. 5. Combined with other tumors at the time of initial diagnosis. 6. Patients who have previously participated in other clinical trials and have not yet terminated the trial. 7. Patients who have acute infection that difficult to control.