Dr. Weinberg on the Role of Cetuximab in Metastatic CRC

Benjamin Weinberg, MD, assistant professor of medicine, Division of Hematology and Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Medstar Health, discusses the role of cetuximab (Erbitux) in treating metastatic colorectal cancer (mCRC).

There was a common misconception that cetuximab was only effective in patients who had RAS and BRAF wild-type mCRC, says Weinberg. Patients with right-sided CRC—tumors that arise from the cecum, ascending colon, hepatic flexure, or beginning of the transverse colon—have a worse prognosis than patients whose disease originates on the left side, from the primary splenic flexure, descending colon, sigmoid, rectosigmoid, and rectum.

Even for patients with RAS wild-type tumors, the EGFR-directed drugs only work up front in those with left-sided primaries, says Weinberg. Patients with right-sided CRC who have RAS or BRAF wild-type mutations—not those with BRAF V600E mutations—should receive EGFR therapy in a much later-line setting, says Weinberg. Now, there are combination regimens that include cetuximab, but using EGFR-directed therapies without also inhibiting BRAF and/or MEK is not recommended, concludes Weinberg.