Colorectal Cancer Coalition

FDA Approves Labeling Changes for Erbitux and Vectibix to Reflect KRAS Status

The Food and Drug Administration (FDA) has approved labeling changes for Vectibix and Erbitux to reflect studies that found the two drugs are not effective in patients whose tumors have mutated KRAS.

The FDA has updated the indication and usage for Vectibix™  (panitumumab) and Erbitux® (cetuximab) to include a statement that:

Retrospective subset analyses of metastatic or advanced colorectal cancer trials have not shown a treatment benefit for ERBITUX or VECTIBIX in patients whose tumors had K-ras mutations in codon 12 or 13 and that the use of ERBITUX or VECTIBIX is not recommended for the treatment of colorectal cancer with these mutations.

The American Society of Clinical Oncology (ASCO) recommends that patients whose treatment might include monoclonal antibodies against EGFR have their tumors tested for KRAS and that those with tumor KRAS mutations not be treated with those antibodies.

Provisional Clinical Opinion: Based on systematic reviews of the relevant literature, all patients with metastatic colorectal carcinoma who are candidates for anti-EGFR antibody therapy should have their tumor tested for KRAS mutations in a CLIA-accredited laboratory. If KRAS mutation in codon 12 or 13 is detected, then patients with metastatic colorectal carcinoma should not receive anti-EGFR antibody therapy as part of their treatment.

The National Comprehensive Cancer Network updated their guidelines for colorectal cancer treatment last November to include testing for KRAS mutations and not treating only those patients without mutations (wild-type) with Erbitux or Vectibix.

New to the NCCN Guidelines is the recommendation that a determination of the KRAS gene status of either the primary tumor or a site of metastasis should be part of the pre-treatment work-up for all patients diagnosed with metastatic colorectal cancer.

Another important update to the NCCN Guidelines is that the epidermal growth factor receptor (EGFR) inhibitors, cetuximab (Erbitux®, Bristol-Myers Squibb Company/ImClone Systems Incorporated) and panitumumab (Vectibix®, Amgen), either as single agents, or, in the case of cetuximab, in combination with other agents, are now recommended only for patients with tumors characterized by the wild-type KRAS gene.

Amgen, the manufacturers of Vectibix and ImClone Systems, who make Erbitux, announced the changes in press releases.

C3 has more information about KRAS mutations and the studies that showed no benefit for treatment with cetuximab or panitumumab for patients whose tumors had those mutations.

Disclosure: C3 has accepted funding for projects and educational programs from Amgen, Imclone Systems, Bristol Myers Squibb, and Eli Lilly in the form of unrestricted educational grants. C3 has ultimate authority over website content.

This news article was originally posted on July 21st, 2009 and was accurate at the time of publication. Since then, information may have changed or links may now be outdated. Please call our Answer Line 1-877-427-2111 for the latest information, or talk to your doctor before making any medical decisions.

Posted by Kate Murphy on July 21st, 2009
Tags: Erbitux, FDA, KRAS, Vectibix