Metastatic colorectal patients benefit from cetuximab vs bevacizumab

18 Aug 2014

Patients with a specific type of metastatic colorectal cancer ("KRAS exon 2 wild type") achieved longer overall survival by receiving cetuximab vs bevacizumab.

FOLFIRI and cetuximab vs FOLFIRI and bevacizumab

In particular, the longer survival was achieved through FOLFIRI+cetuximab compared to FOLFIRI+bevacizumab. These are the conclusions of a phase 3 trial (which researchers call "FIRE-3" trial) published in the journal "Lancet Oncology".

While cetuximab and bevacizumab have both been shown to improve outcomes in patients with metastatic colorectal cancer when added to chemotherapy regimens, their comparative effectiveness when partnered with first-line "fluorouracil, folinic acid, and irinotecan" (FOLFIRI) is unknown.

Phase 3 trial recruited 752 metastatic colorectal patients

In the open-label, randomized, phase 3 FIRE- 3, trial Professor Volker Heinemann, from the University of Munich, and colleagues set out to explore whether cetuximab or bevacizumab was a more effective partner for FOLFIRI in first-line treatment of metastatic colorectal cancer.

Patients were initially recruited without regard to KRAS tumor mutation status.

However, following reports that cetuximab was not active in patients with tumor KRAS exon 2 mutations (so-called codon 12 or 13) enrollment was restricted to patients without KRAS exon 2 mutations (i.e. "wild type").

Between January 2007 and September 2012, 752 patients from 116 centers in Germany and Austria were randomly assigned to a treatment group.

For the 593 patients with KRAS exon 2 wild-type tumors, 297 were assigned to FOLFIRI plus cetuximab and 295 to FOLFIRI plus bevacizumab.

Results: slightly higher benefit from cetuximab vs bevacizumab

Results showed that 184 patients in the cetuximab group (62%) achieved an objective response compared with 171 in the bevacizumab group (58%).

Furthermore, median progression free survival was 10 months in the cetuximab group versus 10.3 months in the bevacizumab group.

However, median overall survival was 28.7 months in the cetuximab group compared with 25 months in the bevacizumab group.

The most common grade 3 or worse adverse events in both treatment groups were

hepatotoxicity (affecting 25% of cetuximab patients versus 21% of bevacizumab patients),
skin reactions (affecting 26% of cetuximab patients versus 2% of bevacizumab patients) and
diarrhea (affecting 11% of cetuximab patients versus 14% of bevacizumab patients).

“Our data suggest that FOLFIRI plus cetuximab should be the chosen first-line treatment regimen for patients with RAS wild-type metastatic colorectal cancer,” wrote the authors.

Source: eCancer News

Metastatic colorectal patients benefit from cetuximab vs bevacizumab