Inclusion Criteria:

- Patient has given written informed consent before any trial specific treatment

- Histological proven diagnosis of colorectal cancer, metastatic or inoperable
advanced, not amenable to curative therapy

- Measurable disease, defined as at least one lesion (outside of irradiated areas) that
can be measured in at least one dimension as ≥ 10 mm (≥ 15 mm in case of lymph nodes)
according to RECIST v1.1

- Tumour with wild-type KRAS and wild-type BRAF gene

- No previous systemic chemotherapy for metastatic disease (previous adjuvant
chemotherapy is allowed if completed >6 months before randomization, previous rectal
radio-chemo therapy if completed >1 month before randomization)

- WHO performance status 0 or 1

- Age >75 years; or: age ≥ 70 years with at least one of the following factors:

- Any functional dependence as measured by Instrumental Activities of Daily Life
(IADL). Significant comorbidity according to the Cumulative Illness Rating Scale for
geriatric patients (CIRS-G; any severe comorbidity > grade 3 or a total score > 5
qualifies)

- Neutrophils ≥ 1.5 x 109/L, platelets ≥ 100 x 109/L

- Bilirubin ≤ 2.0 x Upper Limit of Normal (ULN) (unless known Gilbert-Meulengracht
syndrome), aspartate aminotransferase (AST)<2.5xULN

- Calculated creatinine clearance ≥ 30 ml/min. (according to the formula of
Cockcroft-Gault)

- Patient is able to swallow oral medication

- Baseline Quality of Life forms have been completed

Exclusion Criteria:

- Documented or suspected cerebral and/or leptomeningeal metastases (no cerebral
baseline imaging required in asymptomatic patients)

- Risk of rapid deterioration due to tumor symptoms or tumor complications

- Synchronous or prior malignancy other than adequately treated non-melanomatous skin
cancer or in situ carcinoma of the cervix, other malignancies unless disease free > 2
years

- Prior anti-EGFR (Epidermal Growth Factor Receptor) antibody therapy

- Severe or uncontrolled cardiovascular disease (e.g. acute coronary syndromes, cardiac
failure NYHA (New York Heart Association) III or IV, clinically relevant myopathy,
history of myocardial infarction within the last 12 months, significant arrhythmias)

- Concurrent severe uncontrolled medical illness (judged by the investigator) which
could impair the ability of the patient to participate in the trial (e.g.
uncontrolled infection, uncontrolled diabetes mellitus, active autoimmune disease)

- Known dihydropyrimidine dehydrogenase (DPD) deficiency

- Known hypersensitivity to trial drugs or hypersensitivity to any other component of
the trial drug

- Definite contraindications for the use of corticosteroids or antihistamines as
premedication

- Lack of physical integrity of the upper gastrointestinal tract or malabsorption
syndrome or history of inflammatory intestinal disease, or other disease which could
alter drug absorption

- Psychiatric disorder precluding understanding of information on trial related topics,
giving informed consent, filling out QL forms, or interfering with compliance with
oral drug intake

- Any concomitant drugs contraindicated for use with the trial drugs according to the
Swissmedic approved product information

- Concurrent treatment with other experimental drugs or other anti-cancer therapy
and/or treatment in a clinical trial within 30 days prior to randomization