In 2014 the European Medicines Agency included exon 2, 3 and 4 KRAS and NRAS testing for the selection of metastatic colorectal cancer (mCRC) patients eligible for the therapy with anti-EGFR monoclonal antibodies.
Hence, ligand-dependent tumor suppressor signaling using therapeutic ephA2 agonists might offer new therapeutic opportunities to clinically widen the use of cetuximab in NRAS-mutated and/or ephA2-dependent mCRC tumors.
FIRE-3 evaluated first-line FOLFIRI plus cetuximab (FOLFIRI/Cet) versus FOLFIRI plus bevacizumab (FOLFIRI/Bev) in mCRC patients with RAS-WT tumour (i.e. wild-type in KRAS and NRAS exons 2-4).
Analysis of KRAS/NRAS Mutations in a Phase III Study of Panitumumab with FOLFIRI Compared with FOLFIRI Alone as Second-line Treatment for Metastatic Colorectal Cancer.
Analysis of K- and N-RAS mutations is mandatory before planning treatment of metastatic colorectal cancer, because only RAS wild-type (WT) patients can benefit from treatment with anti-EGFR monoclonal antibodies (cetuximab and panitumumab).
Adding cetuximab to FOLFIRI (5-fluorouracil, leucovorin, irinotecan) significantly improved progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) in patients with KRAS or RAS (KRAS/NRAS, exons 2-4) wild-type (wt) metastatic colorectal cancer (mCRC) in the first-line CRYSTAL study.
Metastatic colorectal cancer (mCRC) patients with mutant KRAS or NRAS are ineligible for anti-epidermal growth factor receptor (anti-EGFR) therapy, as RAS mutations activate downstream pathways independently of EGFR and induce primary resistance.