The Combination of Fruquintinib, Tislelizumab and Stereotactic Ablative Radiotherapy in Metastatic Colorectal Cancer(RIFLE)

Inclusion Criteria:

• Aged over 18 years old, regardless of gender
• Fully informed and willing to provide written informed consent for the trial
• ECOG performance status 0-1
• Has an investigator determined life expectancy of at least 6 months
• Histologically or cytologically confirmed stage IV colorectal cancer (UICC 8thversion)
• Has at least 2 measurable oligometastatic lesions on imaging (RECIST version 1.1). Onewill be treated with SABR and the other will be biopsied and evaluated against RECIST 1.1.
• Has progressive disease after receiving first-line standard antitumor therapy (chemotherapeutic agents including fluorouracil, oxaliplatin and irinotecan); previousneoadjuvant or adjuvant pelvic area radiotherapy is allowed; subjects included in thesafety introduction phase may include third-line treatment or above, but thesesubjects will not be included in the final statistical analysis.
• Subjects receiving adjuvant oxaliplatin should progress during adjuvant therapy orwithin 6 months after completion.
• Demonstrate adequate organ function (bone marrow, liver, kidney and clotting function)within 7 days before the first administration without using blood products orhematopoietic stimulating factors.
• Subjects who withdraw from standard treatment before disease progressing due tounacceptable toxicity and exclude the use of the same drug are also allowed to beincluded.
• Non pregnant or lactating patients. Effective contraceptive methods should be usedduring the study and within 6 months of the last administration.

Exclusion Criteria:

• Pregnant or lactating women
• The presence of a clinically detectable second primary malignancy, or history of othermalignancies within 5 years excluding adequately treated non-melanoma skin cancer,carcinoma in situ of cervix and superficial bladder tumor (non-invasive tumor, orcarcinoma in situ, or T1)
• Baseline laboratory indicators do not meet the following criteria: neutrophils ≥1.5×10^9/L, Hb≥90g/L, PLT≥100×10^9/L , ALT ≤2.5 ULN, AST ≤2.5 ULN, Cr≤ 1.5 ULN orcreatinine clearance rate <50ml/min, TBIL ≤1.5 ULN, APTT ≤1.5 ULN, PT ≤1.5 ULN (thecriteria of patients with liver metastasis: PLT ≥80×10^9/L, ALT ≤5 ULN, AST ≤5 ULN,TBIL ≤2.5 ULN)
• Serious electrolyte abnormalities
• Urinary protein ≥ 2+, or 24-hour urine protein ≥1.0g/24h
• Uncontrolled hypertension: SBP >140mmHg or DBP > 90mmHg
• Receiving radiotherapy within 4 weeks
• Receiving anti-VEGF or anti-EGFR therapy within 4 weeks
• Stroke event or transient ischemic attack occurred within 12 months
• A history of arterial thrombosis or deep vein thrombosis within 6 months; a history ofbleeding or evidence of bleeding tendency within 2 months
• A histroy of heart disease within 6 months (including congestive heart failure, acutemyocardial infarction, severe/unstable angina, coronary artery bypass grafting,cardiac insufficiency ≥ NYHA grade 2 and LVEF<50%)
• Uncontrolled malignant pleural effusion, ascites, or pericardial effusion
• Previous treatment with immunotherapy or fruquintinib
• The presence of gastrointestinal diseases such as gastric or duodenal active ulcers,ulcerative colitis or unresected tumors with active bleeding; or other conditionslikely to cause gastrointestinal bleeding or perforation; or unhealed gastrointestinalperforation or gastrointestinal fistula after surgical treatment
• A history of liver disease including, but not limited to HBV infection or HBV DNApositive(≥1×10^4/ml), HCV infection or HCV DNA positive(≥1×10^3/ml) and livercirrhosis
• Serious mental abnormalities