Background:
- Cetuximab (CTX) and Panitumumab (PMB) therapies directed at EGFR have been restricted to left-sided CRC harboring wildtype KRAS (KRASWT), limiting their utility.
- Approximately 50% of mCRC fail to respond to EGFRi, thus identification of predictive biomarkers is an unmet need.
- Here we evaluate a prespecified 203 gene expression score measuring cetuximab sensitivity (CTX-S) in a large, real-world population of RAS/BRAF mutant vs wild-type and in right- vs left-sided tumors.