Erbitux and Vectibix

ErbituxBristol-Myers Squibb, Eli Lilly, and Amgen are now able to state that colon cancer patients with a mutation to the KRAS gene do not respond to two of their drugs. The FDA has approved revised labeling for cetuximab (Erbitux, Bristol-Myers Squibb/ImClone) and panitumumab (Vectibix, Eli Lilly and Amgen), which is in the same drug class. Merck KGaA markets Erbitux outside the U.S.

Although companies usually want their medications to be used by as many patients as possible, they are recognizing the value of tailoring drug therapy to specific patients based on genetic or other biologic markers. The labeling changes apply to patients who should not receive cetuximab and panitumumab.

In January, the American Society of Clinical Oncology recommended that patients with a mutated form of KRAS not be treated with this drug class for advanced colon cancer drugs. Not using cetuximab as a first-line treatment for these patients could save about $600 million a year.

Sources: Amgen, July 17, 2009