A new class of anti-cancer drugs, called tyrosine kinase inhibitors or anti-EGFR drugs, selectively targets cells within the body that have a specific molecular defect that is believed to cause dangerous cell behaviors such as uncontrolled proliferative growth and high metastatic potential – behaviors that typically are associated with aggressive cancer.  The defect occurs within the interior of the cell in a region that is called the tyrosine kinase domain and it involves a complicated chemical process called EGFR signaling. 

When tyrosine kinase inhibitors work, they can be highly beneficial, causing tumor shrinkage or promoting stable disease and extending survival.  However, as with most of the newer, targeted therapy drugs, tyrosine kinase inhibitors only work for a small percentage of the patients who receive them.  In various studies, response rates in single agent and combined anti-EGFR drug therapy ranged from around 10% to 66%, depending upon the cancer type and the patient population involved.  Further, the drugs are expensive and have been associated with toxic side effects.  Finally, to make matters worse, no molecular (gene-based) test has been proven to tell reliably who will benefit from anti-EGFR treatment.

In contrast, the Weisenthal Cancer Group EGFRx™ profile has been shown to correlate highly with patient response to anti-EGFR treatment and with overall patient survival.  Reported prospectively, EGFRx™ profile results reliably identified patients who did or did not respond to treatment with anti-EGFR drugs and also those who achieved superior survival after treatment.  

Dr. Weisenthal presented data (click here) describing his EGFRx assay at the 2006 annual meeting of ASCO (American Society of Clinical Oncology) and other international cancer symposia. 

The EGFRx™ targeted therapy profile includes analysis of the following targeted drugs: erlotinib (Tarceva), gefitinib (Iressa®), sorafenib (Nexavar®), and sunitinib (Sutent®).  For certain types of cancer, a drug called imatinib (Gleevec®), which works in a very different way, may be tested.