Cetuximab biweekly plus mFOLFOX6 as first-line therapy in patients (pts) with KRAS wild-type (wt) metastatic colorectal cancer (mCRC): An interim analysis of the CEBIFOX trial.

e14502 Background: Combination of mFOLFOX6 with weekly cetuximab is a standard first line regimen in pts with KRAS wt mCRC. Weekly application of cetuximab increases the in-hospital time of pts with negative impact on quality of life. This multicentric phase II trial evaluates the efficacy of mFOLFOX6 + biweekly cetuximab as first line therapy in KRAS wt mCRC. Methods: Pts with KRAS wt mCRC who were not candidates for primary metastasectomy received cetuximab (500 mg/m2 every 2 weeks) in combination with mFOLFOX6 (oxaliplatin 85 mg/m2, folinic acid 400 mg/m2, 5-FU 400 mg/m2 bolus and 2,400mg/m2 over 46 h q14d). Primary endpoint was objective response rate (ORR) per RECIST 1.0, secondary endpoints were safety, secondary resection rate, quality of life (QoL), progression-free survival (PFS) and overall survival. Data of a pre-specified interim analysis are presented in which 13 responders were needed in the first 37 pts (Simon stage I). Results: As of Dec 2012, 46 pts were registered. Fourty three pts received ≥1 course of treatment, and 34 pts were evaluable for response. Baseline characteristics of the ITT population and efficacy data are listed in the Table. Median follow-up was 14.6 months. Grade 3/4 adverse events occurred in 39% of pts, including leukocytopenia (11%), gastrointestinal toxicity (11%), and rash (9%). Median PFS was 9.6 months (95% CI: 5.0 to 14.1). QoL data will be presented. Conclusions: This pre-specified interim analysis supports efficacy and safety of biweekly cetuximab given in combination with mFOLFOX6 in pts with mCRC. A high rate of objective responses and secondary hepatic resections was achieved. Based on these results enrolment in CEBIFOX is continued. Clinical trial information: NCT01051167. [Table: see text]