Phase II portion is an open-label, single arm study. Based on the results of the Phase I portion, weekly KRN330 (0.5 mg/kg) and biweekly irinotecan (180 mg/m2) will be used in the Phase II portion. To be eligible for the Phase II portion, a patient will have recurred or progressed within 6 months of the last cycle of FOLFOX/CapOx +/- bevacizumab (first-line or adjuvant regimen for metastatic colorectal cancer). Patients will continue the treatment until disease progression.