Bevacizumab-containing Regimen for Metastatic Colorectal Cancer Failed to Cytotoxic Treatment

Inclusion Criteria:

* Signed informed consent obtained.
* Subjects must be able to understand and willing to sign a written informed consent.
* Subjects \> 18 years of age
* Subjects must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 2.
* Histological or cytological diagnosis of adenocarcinoma of the colon or rectum.
* Subjects have unresectable metastatic lesions.
* Subjects failed to respond to oxaliplatin, irinotecan and fluorouracil.
* Subjects have at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria measured within 4 weeks prior to registration.
* Leukocytes ≥ 3.0 x109/ L, absolute neutrophil count (ANC) ≥ 1.5 x109/ L, platelet count ≥ 100 x109/ L, hemoglobin (Hb) ≥ 9g/ dL.
* Total bilirubin ≤1.5 x the upper limit of normal (ULN).
* Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 5 x ULN.
* Amylase and lipase ≤ 1.5 x the ULN.
* Serum creatinine ≤ 1.5 x the ULN.
* Calculated creatinine clearance or 24 hour creatinine clearance ≥ 50 mL/ min.

Exclusion Criteria:

* Any previous or concurrent cancer that is distinct in primary site or histology from colorectal cancer within 5 years prior to this study.
* Extended field radiotherapy within 4 weeks or limited field radiotherapy within 2 weeks prior to randomization.
* Major surgical procedure, open biopsy, or significant traumatic injury within 4 weeks before start of study medication.
* Uncontrolled hypertension. (systolic blood pressure \> 150 mmHg or diastolic pressure \> 90 mmHg despite optimal medical management).
* Significant cardiovascular disease including unstable angina or myocardial infarction within 6 months before initiating study treatment or a history of ventricular arrhythmia
* Arterial or venous thrombotic or embolic events such as cerebrovascular accident (including transient ischemic attacks), deep vein thrombosis or pulmonary embolism within the 6 months before start of study medication.
* Any evidence of active infection.
* Known history of human immunodeficiency virus (HIV) infection.
* History of bleeding diathesis or coagulopathy.
* History of interstitial pneumonitis or pulmonary fibrosis
* Pregnancy or lactation at the time of study entry.
* Any history of or currently known brain metastases.
* Known dihydropyrimidine dehydrogenase (DPD) deficiency
* Any illness or medical conditions that are unstable or could jeopardize the safety of the subjects and his/her compliance in the study.
* Subjects with known allergy to the study drugs or to any of its excipients.
* Current or recent (within 4 weeks prior to starting study treatment) treatment of another investigational drug or participation in another investigational study.