On Feb. 1, 2004, the U.S. Food and Drug Administration (FDA) announced it had approved Cetuximab, a recombinant human/mouse chimeric epidermal growth factor receptor (EGFR) monoclonal antibody, to be used in combination with irinotecan for the treatment of EGFR-expressing, metastatic colorectal cancer in patients who had failed to improve with irinotecan-based chemotherapy.

Cetuximab was also approved for administration as a single agent in the treatment of patients with EGFR-expressing, metastatic colorectal cancer who are intolerant to irinotecan-based chemotherapy.