Inclusion Criteria:

          1. Signed and dated written informed consent prior to any study specific procedure;

          2. Age: ≥18 years;

          3. Evidence of newly diagnosed stage IV metastatic colorectal cancer. Primary tumor
             location on the left side of the Colon (including left splenic flexure) or rectum;

          4. Demonstrated wild-type RAS mutation status in the tumor (primary tumor or metastasis)
             by local assessment;

          5. Tumor tissue specimen shows high ανβ6 integrin expression, as determined by central
             laboratory assessment;

          6. Tumor tissue specimen (formalin-fixed, paraffin-embedded block) preferably from
             primary resection and/or if available from a surgical sample from metastatic site must
             be available for central laboratory based ανβ6 integrin expression analysis. (No Fine
             Needle Aspiration [FNA] will be accepted);

          7. At least 1 radiographically documented measurable lesion in a previously
             non-irradiated area according to RECIST (Version 1.1), i.e., this lesion must be
             adequately measurable in at least 1 dimension (longest diameter to be recorded) as ≥2
             cm by conventional techniques or ≥1 cm by spiral CT scan;

          8. Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-1;

          9. Females of childbearing potential must have a negative pregnancy test at screening and
             be willing to have additional pregnancy tests during the study;

        Exclusion Criteria:

          1. Demonstrated any RAS or BRAF mutation;

          2. Prior anti-EGFR or other targeted therapy;

          3. Prior chemotherapy of the colorectal cancer, except for (neo) adjuvant therapy
             completed at least 6 months before randomization;

          4. Radiotherapy (localized radiotherapy for pain relief is allowed to non-target
             lesions);

          5. Investigational drug treatment for the treatment of malignancies in the past;

          6. Concurrent participation in another interventional clinical study;

          7. Pregnancy (exclusion confirmed with beta-hCG test) or lactation;

          8. Any history or evidence of brain metastases or leptomeningeal metastases;

          9. History of secondary malignancy within the past 5 years, except for basal cell
             carcinoma or carcinoma in situ of the cervix uteri, if treated with curative intent;

         10. Concomitant chronic systemic immune or hormone therapy not indicated in this study
             protocol (except for physiologic replacement; steroids up to 10 mg per day of
             prednisone equivalent or topical and inhaled steroids are allowed);

         11. Clinically relevant coronary artery disease (New York Heart Association [NYHA]
             functional angina classification III/IV), congestive heart failure (NYHA III/IV), or
             clinically relevant cardiomyopathy;

         12. Uncontrolled hypertension defined as systolic blood pressure >160 mmHg and/or
             diastolic blood pressure >100 mmHg under resting conditions;

         13. History of myocardial infarction in the last 12 months, or a high risk of uncontrolled
             arrhythmia, coagulation disorder associated with bleeding or recurrent thrombotic
             events, with the exception of arterial fibrillation treated with anti-coagulants;

         14. Recent peptic ulcer disease (endoscopically proven) within 6 months of randomization,
             chronic inflammatory bowel disease, or acute/chronic ileus;

         15. Active infection (requiring IV antibiotics and/or antiviral therapy), including active
             tuberculosis, active or chronic Hepatitis B or C, or ongoing HIV infection, AIDS;

         16. Presence of any contra-indications or known hypersensitivity to treatment with
             abituzumab, cetuximab, and FOLFIRI, or to any of the excipients of these drugs;

         17. Concomitant treatment with prohibited medications;

         18. Medical or psychological conditions that would not permit the patient to complete the
             study.