There is some evidence that patients having a specific type of KRAS gene mutation may respond better to Erbitux® (cetuximab) chemotherapy than others who have KRAS-gene mutations.
Previous studies have shown that people with KRAS-mutated tumors did not respond to Erbitux®, and practice guidelines now recommend testing all tumor cells for the mutation before starting Erbitux therapy in patients with recurrent, advanced colorectal cancer.
The study, reported in the Oct. 27 Journal of the American Medical Association (JAMA), examined both the data and tissue samples of 579 patients in several studies who received Erbitux® between 2001 and 2008 for chemotherapy-refractory cancer. Those patients with “codon-13” mutations had longer overall and progression-free survival by several months than those with other KRAS mutated tumor cells. Laboratory tests of tumor cell responses also showed that codon-13-mutated cells responded to cetuximab when other KRAS-mutated cells did not.
The study authors concluded that “Evaluation of cetuximab therapy in these tumors in prospective randomized trials may be warranted.”
What it means for patients:
Current evidence has shown the codon-13 type of KRAS mutation to be relatively rare, and more research on therapy response is necessary. It is probably too soon to change recommendations for therapy for those having the codon-13 mutation.
Source: Journal of the American Medical Association, Oct. 27, 2010
Disclosure: The Colorectal Cancer Coalition has received funding from Eli Lilly & Company, Bristol-Myers Squibb and ImClone Systems, the companies that manufacture and market Erbitux, in the form of unrestricted educational grants. The Coalition has ultimate authority over website content.