EZN-2208 will be administered by i.v. infusion weekly for 3 weeks in 4-week cycles. The cetuximab infusion will be administered before the EZN-2208 (Arm B) or irinotecan (Arm C) infusion. Study treatment will be continued until evidence of disease progression, unacceptable toxicity, or withdrawal of the patient's consent for participation in the study.
Approximately 220 patients will be enrolled in this study: approximately 100 patients in the K-RAS mutated arm and approximately 120 patients in the wild-type K-RAS arm.