Ivarmacitinib Combined With Camrelizumab and Fruquintinib for Patients With Metastatic Colorectal Cancer After Failure of Second-line or Later Treatment, A Phase II Study

Inclusion Criteria: 1. Patients with histologically or cytologically and radiologically confirmed advanced metastatic or recurrent colorectal cancer; 2. Aged between 18-75 years; 3. ECOG status of 0-1; 4. At least one measurable lesion (RECIST v1.1); 5. Failure of at least second-line standard treatment 6. No history of treatment with JAK1 inhibitors; 7. Voluntarily sign the informed consent form. Exclusion Criteria: 1. History of previous treatment with a JAK1 inhibitor; 2. History of active autoimmune disease or primary immunodiciency within the past 2 years; 3. Allergic to monoclonal antibodies or food additive carboxymethylcellulose sodium and its components; 4 Major cardiovascular and cerebrovascular diseases: such as cerebrovascular accident or myocardial infarction within 6 months before enrollment, uncontrolled hypertension, unstablegina, heart failure (NYHA grade II-IV), severe arrhythmia requiring drug treatment, etc.; 5\. Suffered from other malignant tumors within5 years before enrollment (excluding excised basal cell carcinoma of the skin and cervical carcinoma in situ); 6. Vulnerable groups: including patients with mental, cognitive impairment, critical patients, minors, pregnant or lactating women, illiterate, etc.; 7. Severe chronic obstructive pulmonary disease (COPD, interstitial lung disease, or other diseases that severely affect pulmonary function; 8. Severe hepatic insufficiency, ALT and AST ≥ 25 × ULN (without liver metastasis), ALT and AST ≥ 5.0 × ULN (patients with liver metastasis); 9. Se renal insufficiency (CrCl \< 30 or 60 mL/min); 10. Previous anticancer treatment-induced toxicities not recovered ≤ grade 1 (excluding alopecia); 11. Patients with venous thrombosis; 12. Active tuberculosis,gal and/or viral infection.