Inclusion Criteria:

- Histologically verified adenocarcinoma in colon or rectum

- Age >18

- Metastatic colorectal cancer progressed after chemotherapy regimens containing
fluoropyrimidines, oxaliplatin and irinotecan.

- KRAS mutation in primary tumour or metastasis.

- Measurable disease according to RECIST

- ECOG performance status 0, 1 or 2

- Adequate function of liver, kidneys and bone marrow measured by biochemistry (max. 2
weeks before enrolment)

- EDTA clearance: Uncorrected GFR > 45 ml/min.

- Neutrophilocytes ≥1.5 x 10^9/l, leukocytes ≥3.0 x 10^9/l, thrombocytes ≥100x10^9/l

- ALAT ≤ 3 x upper normal value (ULN), bilirubin ≤ 3 x upper normal value, Aptt and INR
normal (or 2-3 at AC treatment). (ALAT and basic phosphatase ≤ 5 x upper normal value
in case of liver metastases).

- Blood samples and paraffin embedded tissue from primary tumour and/or metastases for
translational research.

- Fertile men and women (women <2 year after last menstruation) must use efficient
birth control.

- Signed informed consent.

Exclusion Criteria:

- Clinically significant other concurrent disease making the patient unfit for
participation in the study according to the investigator.

- Other malignant disease within 5 years prior to study enrolment, except from
planocellular and basal cell carcinomas in the skin or carcinoma-in-situ cervix.

- Other experimental treatment within 30 days prior to treatment start.

- Pregnant or breastfeeding women.

- Clinical or radiological signs of CNS metastases.

- Planned radiation of target lesions.

- Concurrent vaccination against yellow fever.