Background: In PEAK, progression-free survival (PFS) was similar and overall survival (OS) was improved with pmab + FOLFOX6 relative to bev + FOLFOX6 in patients (pts) with WT KRAS exon 2 mCRC. In an extended RAS analysis (exons 2, 3, and 4 of KRAS/NRAS), this improvement was enhanced in pts with WT RAS. This analysis evaluates pts who received subsequent biologic therapy in PEAK. Methods: Kaplan-Meier medians for OS were estimated for pts receiving pmab/subsequent anti-VEGF tx and pts receiving bev/subsequent anti-EGFR tx. Analyses were performed on pts with WT KRAS exon 2 and WT RAS from an exploratory, updated analysis (03Jan2013). Results are from the time of randomization. Results: Demographic and baseline characteristics were generally similar with differences of < 20% between arms. Results are shown (Table). Prespecified analyses suggest that individual RAS exons that are WT favor the pmab arm and will be presented. Conclusions: In this exploratory analysis, the time and % of pts to biologic subsequent tx were similar between the arms. Median OS was observed to be longer for pts receiving pmab/subsequent anti-VEGF tx relative to pts receiving bev/subsequent anti-EGFR tx and the improvements were similar to that in the total populations of the WT KRAS exon 2 and WT RAS groups. Clinical trial information: NCT00819780.