Inclusion Criteria:

- Written informed consent.

- Patients of an age ≥ 18 years and < 71

- Patients with an ECOG performance status ≤ 2

- Confirmed histological diagnosis of colorectal carcinoma with metastatic disease and
wild-type KRAS.

- Presence of at least one target lesion that is measurable one-dimensionally (not
located in an irradiated region).

- Life expectancy greater than 12 weeks.

- First evidence of chemotherapy-naïve metastatic disease. Adjuvant chemotherapy is
allowed if it has been more than 6 months since the treatment was finished and there
have been no signs of disease progression, neither during treatment nor during the 6
months following its completion.

- Adequate medullar reserve:

- Absolute neutrophil count ≥ 1.5 x 109/L

- Platelet count ≥ 100 x 109/L

- Haemoglobin ≥ 9 g/dL

- Adequate renal function: Creatinine clearance > 30 mL/min, calculated using the
Cockroff-Gault formula, or a serum creatinine < 2 mg/dL or 177 umol/L

- An adequate liver function: ASAT (SGOT) and ALAT (SGPT) ≤ 2.5 x ULN (≤ 5 x ULN if
there are liver metastases). Total bilirubin < 1.5 x ULN. Alkaline phosphatase ≤ 2.5
x ULN ( ≤ 5 x ULN in the case of liver metastases or ≤ 10 x ULN in the case of bone
metastases)

Exclusion Criteria:

- To have received prior systemic treatment for the metastatic disease

- Diagnosis or suspicion of brain or leptomeningeal metastases

- Major surgery or radiotherapy (except for antalgic surgery that does not include
measurable target lesions) during the 4 weeks prior to inclusion in the study.

- Previous administration of monoclonal antibodies, agents inhibiting EGFR signal
transduction or EGFR-targeted treatment.

- Participation in another clinical trial with drugs within the previous 30 days.

- Neoplasm in the 2 years prior to entering the study, except for non-melanoma skin
carcinoma or in situ cervix carcinoma.

- Evidence of previous acute hypersensitivity reaction of any degree to any of the
treatment's components.

- Clinically relevant peripheral neuropathy.

- Signs and symptoms, at the moment of entering the study, of acute or subacute bowel
obstruction.

- A history of an acute episode of ischemic heart disease (angina or acute myocardial
infarction) within the previous 12 months or an elevated risk of heart failure
decompensation or uncontrolled arrhythmia.

- Serious active infection, including active tuberculosis and HIV diagnosis.

- Chronic immunological or hormonal treatment, except for hormone replacement treatment
at physiological doses.

- Known drug or alcohol abuse.

- Legal incapacity or limited legal capacity.

- Pregnancy or breastfeeding. Premenopausal women must have a negative pregnancy test
in urine or blood before entering the trial. Patients and their partners must take
contraceptive measures (hormonal, barrier, or abstinence) if the possibility of
conception exists, during the study and for 3 months after the end of the treatment
thereof.

- Any geographical or social circumstance or any medical or psychological alteration
that, in the investigator's opinion, will not allow the patient to conclude the
study.