The US Food and Drug Administration (FDA) has approved revisions to the US prescribing information for the epidermal growth factor receptor (EGFr) class of antibodies, including panitumumab (Vectibix). This decision follows the FDA's December 2008 Oncologics Drugs Advisory Committee (ODAC) meeting where the clinical utility of the KRAS gene as a predictive biomarker in patients with metastatic colorectal cancer (mCRC) treated with anti-EGFr antibody was discussed.
The Indication and Usage section of the prescribing information has been updated to include that retrospective subset analyses of metastatic colorectal cancer trials have not shown a treatment benefit for panitumumab in patients whose tumors had KRAS mutations in codon 12 or 13. Use of panitumumab is not recommended for the treatment of colorectal cancer with these mutations.
The Clinical Studies section of the prescribing information has been updated to reflect results from retrospective analyses across seven randomized clinical trials with agents in this class. This includes the first phase III analysis that showed mCRC patients with mutated KRAS tumors do not respond to monotherapy with an EGFr-inhibiting antibody.