Inclusion Criteria:

- Man or woman ≥ 18 years.

- Competent to comprehend, sign, and date an IEC-approved (Ethics Committee) informed
consent form

- Histologically-confirmed metastatic adenocarcinoma of the colon or rectum by the
investigator.

- Wild Type K-RAS colorectal cancer determined by the designated Central Laboratory
prior to inclusion in the study in the primary tumor and/or at least one metastasis.

- At least 1 uni-dimensionally measurable lesion of at least > 10 mm with spiral CT per
modified RECIST criteria 1.1. (Response Evaluation Criteria In Solid Tumors)

- Patients with the following characteristics will be included:

1. Recurrence after adjuvant treatment with 5-fluorouracil/folinic acid or
capecitabine +/- radiotherapy with a disease-free interval > than 6 months after
its completion.

2. Recurrence after adjuvant treatment with oxaliplatin +/- radiotherapy with a
disease-free interval > than 12 months

3. De novo diagnosis of the disease.

- Eastern Cooperative Oncology Group performance status of 0 or 1.

- Life expectancy ≥ 3 months

- Adequate bone marrow function

- Adequate Hepatic and metabolic functions

- Adequate Renal function

- Magnesium > LLN (Lower limit of Normal)

Exclusion Criteria:

- Patients they have received prior systemic therapy for the treatment of metastatic
colorectal carcinoma.

- Prior anti-EGFr antibody therapy (eg, cetuximab) or treatment small molecule EGFr
tyrosine kinase inhibitors (eg, erlotinib) or EGFR signal transduction inhibitors.

- Patients who had resection of metastatic disease

- Central nervous system/brain metastases

- Prior malignant tumor in the last 5 years, except a history of basal cell carcinoma
of the skin or pre-invasive cervical cancer.

- Unresolved toxicities from prior systemic therapy that, in the opinion of the
investigator, does not qualify the patient for inclusion

- Presence of peripheral neuropathy (Common Toxicity Criteria (CTC) version 3.0 > grade
1), and of serious nonhealing wound, ulcer, or bone fracture.

- Hormonal therapy, immunotherapy or experimental or approved proteins/antibodies (eg,
bevacizumab) ≤ 30 days before inclusion

- Significant cardiovascular disease including unstable angina or myocardial infarction
within 12 months before initiating study treatment or a history of ventricular
arrhythmia.

- History of interstitial pneumonitis or pulmonary fibrosis or evidence of interstitial
pneumonitis or pulmonary fibrosis on baseline chest CT scan

- Treatment for systemic infection within 14 days before initiating study treatment

- Acute or sub-acute intestinal occlusion and /or active inflammatory bowel disease or
other bowel disease causing chronic diarrhea (defined as > 4 loose stools per day).

- Known positive test for human immunodeficiency virus infection, hepatitis C virus,
chronic active hepatitis B infection

- Any investigational agent within 30 days before enrollment

- Subject who is pregnant or breast feeding

- Surgery (excluding diagnostic biopsy or central venous catheter placement) and/or
radiotherapy within 14 days prior to inclusion in the study.

- Woman or man of childbearing potential not consenting to use adequate contraceptive
precautions