Inclusion Criteria:

          -  Patients must be greater than 18 years of age

          -  Patients must be able to provide informed consent

          -  Patients must have KRAS/NRAS/BRAF wild-type colorectal cancer

          -  Willing to abstain from sexual intercourse or to use an effective form of
             contraception during the study and for 120 days following the last dose of any study
             therapy). This applies to women of childbearing potential as well as fertile men and
             their partners

        Exclusion Criteria:

          -  Patients who have had previous pelvic radiation treatment

          -  Patients who are pregnant or lactating

          -  Patients who have untreated (primary) or uncontrolled Central Nervous System (CNS)
             (primary or metastatic) malignancies; patients with CNS metastases who have undergone
             surgery or radiotherapy or who have been on a stable dose of corticosteroids for at
             least 2 weeks and whose disease is stable prior to the first scheduled day of dosing
             will be eligible for the trial.

          -  History of any second malignancy in the last 3 years; patients with prior history of
             in-situ cancer or basal or squamous cell skin cancer are eligible.

          -  Patients who have received other recent antitumor therapy including any standard
             chemotherapy or radiation within 14 days and bevacizumab within 28 days (and having
             passed the time of any actual or anticipated toxicities) prior to the first scheduled
             dose of the study treatment