Phase II trial of cetuximab (Cmab) plus irinotecan (CPT-11) for chemorefractory Japanese patients with advanced and/or metastatic colorectal cancer (mCRC), to evaluate the efficacy and safety based on KRAS, BRAF, PIK3CA, NRAS, and AKT1 mutation status (T-CORE0801).

e14597 Background: Mutations in the KRAS gene have been identified as negative predictors of response to anti-epidermal growth factor receptor (EGFR) antibody (mAb) therapy among patients with mCRC based on Caucasian studies. To date, few studies have examined the relationship between KRAS status and response to Cmab therapy in Asian populations. Therefore, this prospective study investigated the relationship between the mutation status of KRAS and other EGFR-related genes along with clinical outcomes in response to Cmab + CPT-11 therapy in Japanese patients with mCRC. Methods: Samples that had been collected from 43 chemo-refractory patients with mCRC, who had undergone Cmab + CPT-11 therapy at 11 medical centers in Japan, were subjected to direct DNA sequencing to determine their KRAS, BRAF, PIK3CA, NRAS, and AKT1 status. The response rate (RR) was the primary endpoint along with safety, median progression free survival (mPFS), and median overall survival (mOS) as secondary endpoints. Results: The clini...