Dalotuzumab is a humanized monoclonal antibody (mAb) that targets the insulin-like growth factor type 1 receptor-1 (IGF-1R). Dalotuzumab may act through inhibition of insulin-like growth factor-1 (IGF-1)-mediated cell signaling to cause reductions in tumor growth and spread antibody dependent cell-mediated cytotoxicity.
In preclinical studies, dalotuzumab improved the activity of an anti-epidermal growth factor receptor (EGFR) mAb and the activity of erlotinib, a small molecule inhibitor of EGFR.
All eligible participants will receive cetuximab 400 mg/m\^2 infusion over 120 minutes followed by weekly infusions of cetuximab 250 mg/m\^2 over 60-120 minutes along with irinotecan infusion over 30-90 minutes. Dosage of irinotecan will be the same as most recent pre-study therapy. Participants will then be assigned to one of three treatment double-blind arms.
