Inclusion Criteria:

• Histologically confirmed locally advanced or metastatic colorectal cancer.
• Measurable or evaluable disease according to the Response Evaluation Criteria in Solid Tumors (RECIST)
• ECOG performance status ≤ 2
• Age 18 - 72 years
• Patients with de novo refractory disease (progression of disease as best response at 1st line therapy with FOLFOX/Avastin)
• Adequate liver (Bilirubin ≤ 1.5 UNL, SGOT/SGPT ≤ 4 UNL, ALP ≤ 2.5 UNL),renal (Creatinine ≤ 1.5 UNL) and bone marrow (ANC ≥ 1,500/mm3, PLT ≥100,000/mm3) function
• Patients must be able to understand the nature of this study
• Written informed consent

Exclusion Criteria:

• History of serious cardiac disease (unstable angina, congestive heart failure, uncontrolled cardiac arrhythmias).
• History of myocardial infarction or stroke within 6 months.
• Clinically significant peripheral vascular disease.
• History of abdominal fistula, gastrointestinal perforation or intraabdominal abscess within 28 days prior to Day 0.
• Presence of central nervous system or brain mets.
• Evidence of bleeding diathesis or coagulopathy.
• Patients with known hypersensitive reaction to cetuximab
• Blood pressure > 150/100 mmHg.
• Pregnant or lactating woman.
• Life expectancy < 3 months.
• Previous radiotherapy within the last 4 weeks or > 25% of bone marrow.
• Metastatic infiltration of the liver >50%.
• Patients with chronic diarrhea (at least for 3 months) or partial bowel obstruction or total colectomy.
• Active infection requiring antibiotics on Day 1.
• Second primary malignancy, except for non-melanoma skin cancer and in situ cervical cancer.
• Psychiatric illness or social situation that would preclude study compliance.