Inclusion Criteria:

- Histologically or cytologically proven colorectal cancer

- Unresectable stage IV disease

- K-Ras wild type tumour

- Patients scheduled to undergo chemotherapy with irinotecan and cetuximab

Exclusion Criteria:

- Prior abdominal/pelvic radiotherapy, surgery or chemotherapy within 3 months prior to
inclusion in the study

- Poorly controlled diabetes

- Concomitant serious illness, such as uncontrolled angina pectoris, myocardial
infarction, heart failure, uncontrolled hypertension, infection

- Symptomatic brain metastases

- Pregnancy or participants of reproductive potential who are sexually active and not
willing/able to use medically appropriate contraception