Cetuximab Works Better than Bevacizumab as Initial Treatment for Advanced Colorectal Cancer

ASCO Annual Meeting
June 1, 2013

According to a recent study, initial treatment with the drug cetuximab (Erbitux) plus the chemotherapy regimen FOLFIRI lengthens the lives of patients with metastatic colorectal cancer when compared with bevacizumab (Avastin) plus FOLFIRI. The chemotherapy regimen FOLFIRI includes the drugs leucovorin (Wellcovorin), fluorouracil (5-FU, Adrucil), and irinotecan (Camptosar).  

Cetuximab and bevacizumab are types of targeted therapy, a treatment that targets the cancer’s specific genes, proteins, or the tissue environment that contributes to cancer growth and survival. However, they each target a different method that a cancer can use to grow and spread. Cetuximab and bevacizumab are both commonly used as an initial treatment for colorectal cancer. Cetuximab is only approved for patients with no mutation (change) in the KRAS gene (often called KRAS wildtype), and bevacizumab works for patients with or without a changed KRAS gene, but researchers have not known which of these two drugs is better for patients who do not have a mutated KRAS gene.

As part of this study, 592 patients with a non-mutated KRAS gene received either initial treatment with FOLFIRI plus cetuximab or FOLFIRI plus bevacizumab. Researchers found that it took about the same amount of time for the cancer to worsen, regardless of the treatment used. However, those who received cetuximab lived around four months longer than those who received bevacizumab.

What this means for patients

“This survival benefit is similar to the survival benefit seen in the clinical trials that led to the approval of cetuximab and bevacizumab for colorectal cancer,” said Volker Heinemann, MD, PhD, Professor of Medical Oncology at the University of Munich in Germany. “We suspected that cetuximab would work better but we didn’t know this would translate into better survival.”

Questions to Ask Your Doctor

  • What type of colorectal cancer do I have?
  • What is the stage? What does this mean?
  • Will my tumor be tested for a KRAS mutation?
  • What are my treatment options?
  • What treatment plan do you recommend? Why?
  • What are the risks and benefits of this treatment plan?

For More Information

Guide to Colorectal Cancer

Understanding Targeted Treatments

What to Know: ASCO’s Guideline on Tumor Markers for Gastrointestinal Cancers