Inclusion Criteria:
* Age: ≥18 years old.
* Histopathologically and/or cytologically confirmed unresectable metastatic colorectal adenocarcinoma, and patients failed or are intolerant to first-line treatment with oxaliplatin ± VEGF/EGFR.
* At least one measurable lesion (according to RECIST v1.1).
* Eastern Cooperative Oncology Group (ECOG) performance status of 0 \~ 1.
* The expected survival time ≥3 months.
* Subject has adequate biological parameters as demonstrated by the following: Absolute neutrophil count (ANC) ≥1.5×10\^9/L, Platelet count ≥100×10\^9/L, Hemoglobin (Hgb) ≥90 g/L.
* Adequate hepatic function as evidenced by: Total bilirubin ≤1.5 × upper limit of normal (ULN), Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 × ULN, ≤5 × ULN if liver metastases are present. Serum albumin ≥3 g/dL.
* Adequate renal function as evidenced by serum creatinine (Cr) ≤1.5 × ULN or creatinine clearance ≥60 mL/min. Proteinuria \< 2+ (those with proteinuria ≥2+ at baseline had to demonstrate ≤1 g protein per 24 hours).
* Coagulation function: International normalised ratio (INR) ≤1.5, activated partial thromboplastin time (APTT) ≤1.5 × ULN.
* Left ventricular ejection fraction (LVEF) ≥50%.
* Subjects agree to use contraception and are not pregnant or breastfeeding women.
* Agree and be able to comply with the plan during the study period. Provide written informed consent before entering the study screening.
Exclusion Criteria:
* Any other malignancy within 5 years, with the exception of cured in-situ carcinoma or basal cell carcinoma etc.
* Previous treatment with irinotecan/liposomal irinotecan.
* Patients with the primary lesion located in the left colon and RAS/BRAF wild-type who did not use cetuximab on the first line.
* Known as high microsatellite instability (MSI-H) or mismatch repair deficiency (dMMR).
* Massive pleural effusion or ascites requiring intervention.
* Active, uncontrolled bacterial, viral, or fungal infections that require systemic treatment.
* Active HIV infection.
* Combined with uncontrollable systemic diseases within 6 months before the first administration.
* Presence of severe gastrointestinal disease.
* History of major surgery (such as laparotomy, thoracotomy or intestinal resection) within 28 days before the first administration, or plan to undergo major surgery during the study period.
* Presence of interstitial pneumonia or pulmonary fibrosis.
* History of allergy or hypersensitivity to drug or any of their excipients.
* History of pulmonary hemorrhage/hemoptysis ≥Grade 2 (defined as bright red blood of at least 2.5mL) within one month before the first administration.
* Presence of arterial embolism, severe bleeding (excluding bleeding caused by surgery) or tendency for existing embolism or severe bleeding within 6 months before the first administration.
* Combined symptomatic brain metastasis, meningeal metastasis, spinal cord tumor invasion, and spinal cord compression syndrome.
* Use of strong inhibitors or inducers of CYP3A4, CYP2C8 and UGT1A1 within 14 days before the first administration.
* Use other study drug within 1 month before the first administration.
* Patients who are not suitable to participate in this trial for any reason judged by the investigator.
