- ≥18 years old - ECOG 0-2 - diagnosis of adenocarcinoma of the colon or rectum - only one prior chemotherapy regimen for mCRC consisting of first-line fluoropyrimidine-based chemotherapy - radiographically confirmed disease progression must have occurred during or within 6 months of prior first-line chemotherapy - at least one unidimensionally measurable lesion (≥20 mm) - a pretreatment paraffin-embedded tumor tissue from the primary tumor or metastasis had to be available for central analyses of EGFR and biomarker testing. Neither EGFR expression nor KRAS status was required for enrollment.

- all patients were required to have EGFR expression defined as at least 1  membrane staining in  1% of tumor cellsdc-return- had progressed on or following treatment with regimen(s) containing a fluoropyrimidine, oxaliplatin, and irinotecandc-return- had to have received at least two but no more than three prior chemotherapy regimens for metastatic colorectaldc-returncancerdc-return- had to have measurable disease

- histologically confirmed metastatic colorectal carcinoma, with bidimensionally measurable diseasedc-return- at least 18 years, an Eastern Cooperative Oncology Group (ECOG) performance status 8 of 0 or 1, a life expectancy of more than three months, and written informed consentdc-return- Adequate hematologic, hepatic, and renal function (including urinary excretion of no more than 500 mg of protein per day)