Cetuximab biweekly plus mFOLFOX6 as first-line therapy in patients (pts) with KRAS wild-type (wt) (exon 2) metastatic colorectal cancer (mCRC): Primary endpoint and subgroup analysis of the CEBIFOX trial.

3568 Background: The multicenter, single-arm, phase II CEBIFOX trial (Simon`s two stage minimax design) evaluated the efficacy of mFOLFOX6 + biweekly cetuximab (500 mg/m2) as 1st line therapy in KRAS wt (exon 2) mCRC. Final efficacy data as well as extended molecular and clinical subgroup analyses are presented. Methods: Primary endpoint was objective response rate (ORR) per RECIST 1.0, secondary endpoints were safety, metastasectomy rate, quality of life, progression-free (PFS) and overall survival (OS). Extended molecular profiling was performed using NGS-based panel sequencing including NRAS (exon 2-4), KRAS (exon 2-4), BRAF (exon 15) and PI3KCA (exon 10 and 21). Clinical parameters included: tumor localisation (right sided vs. left sided-LCRC), liver-limited disease (LLD), early tumor-shrinkage (ETS), depth of response (DPR), metastasectomy and inflammation markers (neutrophil/lymphocyte ratio-NLR). Differences in ORR, PFS and OS were calculated for subgroups using chi-square and logrank tests. Hazard...