Influence of adjuvant pretreatment on outcome of FIRE-3 (AIO KRK-0306): A randomized phase III study of FOLFIRI plus cetuximab or bevacizumab as first-line treatment for wild-type (WT) KRAS (exon 2) metastatic colorectal cancer (mCRC) patients.

Abstract

515 Background: The FIRE-3 study (AIO KRK-0306) was designed to compare the efficacy of FOLFIRI + cetuximab (cet) to FOLFIRI + bevacizumab (bev) as first-line treatment in KRAS WT mCRC patients. FOLFIRI plus cet resulted in comparable overall response rates (ORR) and progression free survival (PFS) when compared to FOLFIRI + bev. Overall survival (OS) was significantly longer in the FOLFIRI + cet arm. Methods: In an exploratory subgroup analysis, patients pretreated with adjuvant chemotherapy were analyzed by Fisher's exact and log rank-test according to tumor response (ORR) and survival data. Patients of the ITT (n=592) and the final RAS wild-type population (n=400) were investigated. Results: See table. Conclusions: Results in patients treated with any adjuvant chemotherapy mirrored those in the whole study population. In adjuvant pretreated RASwt patients a significantly higher ORR was reached in the cet arm when compared to the bev arm (p=0.01). The role of adjuvant treatment on efficacy of first-line therapy remains to be further evaluated. Clinical trial information: NCT00433927. [Table: see text] [Table: see text]