Inclusion Criteria:
* Unresectable colorectal adenocarcinoma confirmed by histopathology or cytology;
* Patients who have failed first-line standard therapy and are intended to receive second-line standard therapy;
* At least one measurable lesion according to RECIST 1.1 criteria;
* ECOG Performance Status 0-1;
* Estimated life expectancy ≥3months;
* Adequate major organ function;
* Subjects voluntarily participate in this study, sign the informed consent form, and have good compliance.
Exclusion Criteria:
* Allergy to the investigational drug and/or its excipients;
* Pregnant or lactating women;
* Prior treatment with TAS-102;
* Any CTCAE grade 2 or above toxicity caused by previous treatment that has not yet subsided (excluding alopecia, skin pigmentation, and chemotherapy-induced neurotoxicity);
* Known inherited or acquired bleeding (e.g., coagulopathy) or thrombophilia, as in patients with hemophilia; Current or recent (within 10 days before initiation of study treatment) use of a full-dose oral or injectable anticoagulant or thrombolytic agent for therapeutic purposes (prophylactic use of low-dose aspirin and low-molecular-weight heparin is allowed);
* Serious illness, including but not limited to the following:
1. Patients with other malignant tumors within 5 years before enrollment, except basal cell carcinoma of the skin or carcinoma in situ of the cervix;
2. Known brain and/or leptomeningeal metastases;
3. Active infection or fever of unknown origin \> 38.5 ° C ;
4. Poorly controlled hypertension (systolic blood pressure \>150 mmHg and/or diastolic blood pressure \>100 mmHg) with a previous history of hypertensive crisis or hypertensive encephalopathy;
5. Known inherited or acquired bleeding (e.g., coagulopathy)
6. Thrombotic or embolic events, such as cerebrovascular accident (including transient ischemic attack, cerebral hemorrhage, cerebral infarction), pulmonary embolism, etc., occurred within 6 months before the initiation of study treatment;
7. Severe, unhealed or dehiscence wounds and active ulcers or untreated fractures;
8. Myocardial infarction, severe/unstable angina, symptomatic congestive heart failure (NYHA Class III or IV) within the last 12 months;
9. Acute or subacute intestinal obstruction, or chronic inflammatory bowel disease;
10. There are serious psychological or psychiatric abnormalities that affect the compliance of patients to participate in this clinical study.
* Has undergone major surgical treatment (excluding diagnosis) within 4 weeks before the start of the study or is expected to undergo major surgical treatment during the study period;
* Inability to swallow pills, presence of malabsorption syndrome or any condition affecting gastrointestinal absorption;
* The investigator assessed that it is not appropriate to participate in the study.
