Treatment sequence with either irinotecan/cetuximab followed by FOLFOX-4 or the reverse strategy in metastatic colorectal cancer patients progressing after first-line FOLFIRI/bevacizumab: An Italian Group for the Study of Gastrointestinal Cancer phase III, randomised trial comparing two sequences of therapy in colorectal metastatic patients

Abstract

Introduction: The optimal treatment strategy for RAS wild type (WT) mCRC is controversial. Our phase III study investigated the effect of introducing earlier (second-line) or later (third-line) cetuximab in patients progressed after FOLFIRI/bevacizumab first-line.

Patients and methods: mCRC patients progressing after FOLFIRI/bevacizumab first-line were randomised to receive second-line irinotecan/cetuximab followed by third-line FOLFOX-4 (arm A) or the reverse sequence (arm B). Primary end-point was progression-free survival (PFS).

Results: About 54 and 56 patients were randomised in arm A and in arm B, respectively. After a median follow-up of 37.5 months, 100 PFS events were recorded. Median PFS was 9.9 months in arm A and 11.3 months in arm B (Hazard ratio [HR] 1.04, 95% confidence interval [CI]: 0.69-1.56, p = 0.854), while median overall survival was 12.3 months in arm A and 18.6 months in arm B (HR 0.84, 95% CI: 0.55-1.28; p = 0.411). No overall difference in side-effects were observed between the two treatment arms.

Conclusions: This trial did not meet the primary end-point (PFS). Like other preclinical and clinical evidences, our study seems to suggest a reduced activity of cetuximab after a first-line bevacizumab-based therapy.

Keywords: Cetuximab; K-RAS wild type; Metastatic colorectal cancer; Treatment sequence; Treatment strategy.