Inclusion Criteria:

- Histologically confirmed, potentially resectable rectal adenocarcinoma staged as
uT3/4 N0/1 by endosonography or cT3/4 by MRI of the pelvis with or without local
lymph node metastases.

- Wild-type KRAS.

- ECOG-performance status 0 or 1.

- Age ≥ 18 years.

- Laboratory requirements:

- Haematology: Leucocyte count > 3,000/mm³, neutrophil count ≥1.5x109/L,
hemoglobin ≥ 8 g/dL, platelet count ≥100x109/L.

- Hepatic Function: Total bilirubin ≤ 1.5 time the upper normal limit (UNL),
ASAT ≤ 2.5xUNL in absence of liver metastases or ≤ 5xUNL in presence of liver
metastases, ALAT ≤ 2.5xUNL in absence of liver metastases or ≤ 5xUNL in presence
of liver metastases

- Renal Function: Creatinine clearance ≥50 mL/min or serum creatinine ≤1.5xUNL

- Metabolic Function: Magnesium ≥ lower limit of normal, Calcium ≥ lower limit of
normal.

- Negative ß-HCG-serum pregnancy test (females of child bearing potential).

- Willing to use double-barrier contraception during study and for 6 months after the
end of treatment.

- Ability of patient to understand character and individual consequences of clinical
trial

- Written informed consent (must be available before enrollment in the trial)

Exclusion Criteria:

- Prior EGFR targeting or prior chemo- or radiotherapy or tumor surgery.

- Evidence of any distant metastases.

- Manifest or previous secondary malignancies within the last 5 years.

- Uncontrolled infection.

- Clinically significant cardiovascular disease NYHA classification III or IV
(including myocardial infarction, unstable angina, symptomatic congestive heart
failure, serious uncontrolled cardiac arrhythmia) ≤ 1 year before
enrollment/randomization.

- History of interstitial lung disease e.g. pneumonitis or pulmonary fibrosis or
evidence of interstitial lung disease on screening chest CT scan.

- Diabetes mellitus

- Subject pregnant or breast feeding, or planning to become pregnant within 6 month
after the end of treatment.

- Subject (male or female) is not willing to use highly effective methods of
contraception (per institutional standard) during treatment and for 6 months (male or
female) after the end of treatment.

- Active serious illness which renders the patient unsuitable for study entrance,
multiple blood sampling or the above mentioned biopsies.

- History of hypersensitivity to the investigational medicinal product or to any drug
with similar chemical structure or to any excipient present in the pharmaceutical
form of the investigational medicinal product.

- Participation in other clinical trials or observation period of competing trials,
respectively.