Cetuximab weekly (q1w) versus every two weeks (q2w) plus FOLFOX4 as first-line therapy in patients (pts) with KRAS wild-type (wt) metastatic colorectal cancer (mCRC).

3580 Background: FOLFOX4 + q1w cetuximab is a standard 1st-line regimen in KRAS wt mCRC. This trial evaluated FOLFOX4 + q1w cetuximab (Arm A) and FOLFOX4 + q2w cetuximab (Arm B) as 1st-line therapy in KRAS wt mCRC. Methods: Pts with KRAS wt mCRC were randomized to q1w cetuximab (400 mg/m2initial dose then 250 mg/m2/wk) or q2w cetuximab (500 mg/m2 every 2 wks). Both arms received FOLFOX4 (folinic acid 200 mg/m2, then 5-FU 400 mg/m2 bolus, then 5-FU 600 mg/m2 over 22 h on days 1+2, plus oxaliplatin 85 mg/m2 on day 1 q2w). Primary endpoint was objective response rate (ORR). Secondary efficacy endpoints were disease control rate (DCR), progression free survival (PFS) and overall survival (OS). Results: 152 pts with KRAS wt tumors (22 centers in 12 countries) were randomized to arm A (n=75) and arm B (n=77). Baseline characteristics were well balanced. Median follow up for PFS analysis was 16.5 months. Overall ORR (55% vs 59%) and PFS (9.5 mo vs 9.3 mo) were similar in patients with EGFR detected and nondetect...