Alternating Treatment With Fruquintinib and Bevacizumab Plus Capecitabine as Maintenance Therapy After First-Line Treatment in Metastatic Colorectal Cancer

Inclusion Criteria: 1. Patients voluntarily participated in the study, signed the informed consent, and had good compliance; 2. Age 18-75 (including 18 and 75), gender is not limited; 3. Histologically and/or cytologically confirmed metastatic colorectal cancer (stage IV); 4. The patient with at least one measurable lesion (RECIST 1.1) achieved partial remission after 8 cycles of first-line standard chemotherapy (FOLFOX combined with bevacizumab), and the disease remained in an unresectable state. 5. ECOG performance status of 0-2 points; 6. Expected survival ≥12 weeks; 7. Blood test (without blood transfusion within 14 days) 1) Neutrophil absolute value ≥1.5×10\^9/L, platelet ≥100×10\^9/L, hemoglobin ≥90g/L); 2) Liver function test (aspartate aminotransferase and glutamate aminotransferase ≤3×ULN, bilirubin ≤1.5×ULN; In case of liver metastasis, AST and ALT≤5×ULN); 3) Renal function (serum creatinine ≤1.5×ULN, or creatinine clearance (CCr)≥60ml/min); 8. Men and women of childbearing age must use effective contraceptive methods. Exclusion Criteria: 1. Received major surgery within 4 weeks prior to the first drug administration; radiotherapy, radiofrequency ablation, chemotherapy, immunotherapy or molecular targeted therapy for tumors within 2 weeks, and other investigational drugs; 2. Previously received anti-vascular small-molecule targeted drug therapy, such as fuquinitinib, regofenib, etc.; 3. A history of severe intolerance to bevacizumab and capecitabine or 5-Fu (i.e., grade 4 toxicity of one of these drugs; Class 3-4 toxicity of other co-administered drugs is not excluded); 4. Known brain or meningeal metastases: 5. Have hypertension that is not well controlled by antihypertensive medications (systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg); 6. Obvious clinical bleeding symptoms or obvious bleeding tendency and hemoptysis within 3 months prior to treatment. Or treatment of venous/venous thrombosis events within the preceding 6 months, such as cerebrovascular accidents (including transient ischemic attack, cerebral hemorrhage, cerebral infarction), deep vein thrombosis and pulmonary embolism; Long-term anticoagulant therapy with warfarin or heparin, or long-term antiplatelet therapy (aspirin ≥300 mg/day or clopidogrel ≥75 mg/day) is required; 7. Active heart disease, including myocardial infarction, severe/unstable angina in the 6 months prior to treatment. Echocardiography showed that the left ventricular ejection fraction was less than 50%, indicating poor arrhythmia control. 8. The patient had other malignancies (except cured basal cell carcinoma of the skin and carcinoma in situ of the cervix) within the previous 5 years or at the same time; 9. Known allergy to the study drug or any of its excipients; 10. Severe active infection or uncontrolled infection; 11. Any other disease, a clinically significant metabolic abnormality, abnormal physical examination or abnormal laboratory examination, for which, in the investigator's judgment, there is reason to suspect that the patient has a disease or condition unsuitable for the use of the investigational agent; 12. Urine routine indicated urine protein ≥2+, and 24 hours urine protein quantity \>1.0g.