Molecular analysis is now underway to characterize subsets of patients who performed better or worse on either treatment.
For patients with KRAS wild-type untreated colorectal cancer, adding cetuximab or bevacizumab to combination chemotherapy offers equivalent survival, researchers said at the European Society for Medical Oncology 16th World Congress on Gastrointestinal Cancer in Barcelona, Spain.
"The CALGB/SWOG 80405 trial was designed and formulated in 2005, and the rationale was simple: we had new drugs, bevacizumab and cetuximab, and the study was designed to determine if one was better than the other [as a first-line treatment] for patients with colon cancer," said lead study author Alan P. Venook, MD, distinguished Professor of Medical Oncology and Translational Research at the University of California, San Francisco.
The CALGB/SWOG 80405 trial studied patients whose tumors were KRAS wild-type at codons 12 and 13. Patients received mFOLFOX6 or FOLFIRI at the discretion of their doctor and were randomized to cetuximab (578 patients) or bevacizumab (559 patients).
"There was no meaningful difference in outcome between treatment arms," said Venook. "In both arms patients lived close to 30 months. About 10% of patients lived more than 5 years. Overall patients did much better than anticipated and it was indifferent to the type of treatment."
Original report: http://bit.ly/1s4yyhU