Cetuximab with chemotherapy (CT) as first-line treatment for metastatic colorectal cancer (mCRC): Analysis of the CRYSTAL and OPUS studies according to KRAS and BRAF mutation status.

Abstract

3506 Background: The CRYSTAL and OPUS studies showed that adding cetuximab to CT in the first-line treatment of mCRC significantly improved treatment outcome compared with CT alone, in patients (pts) with KRAS wild-type (wt) tumors. This pooled analysis of the CRYSTAL and OPUS pt populations evaluated overall survival (OS), progression-free survival (PFS), and best overall response (OR) using updated data. Methods: The analysis was performed on individual pt data from both studies for all efficacy endpoints according to KRAS/BRAF mutation status. KRAS and BRAF mutation status was determined by quantitative PCR. Treatment arms were compared according to mutation status using log rank and Cochran-Mantel-Haenszel tests. Results: The data with respect to KRAS wt and BRAF tumor mutation status are presented in the Table. Conclusions: This analysis confirms that the addition of cetuximab to CT first line in pts with KRAS wt tumors achieves a statistically significant improvement in OR rate, PFS, and OS compared...