FDA OKs test to assess effectiveness of colorectal cancer drug
The U.S. Food and Drug Administration earlier this month approved the first genetic test that can help some colorectal cancer patients and their doctors determine if the drug Erbitux (cetuximab) would be an effective treatment.
The therascreen KRAS RGQ PCR Kit can provide information about the KRAS gene mutation in patients whose colorectal cancer has spread to other parts of their body. Studies have found that Eribitux is not effective in those who have the mutation.
“This test helps clinicians determine whether this specific treatment is an effective option,” said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostic Device Evaluation and Safety in the FDA’s Center for Devices and Radiological Health.
Colorectal cancer is the third leading cause of cancer death in the United States. According to the American Cancer Society, there were more than 141,000 new colorectal cancer cases in 2011, and nearly 50,000 deaths resulted from colorectal cancer.
Erbitux targets the epidermal growth factor receptor (EGFR) on the surface of colorectal cancer cells. When certain chemicals in the body bind to EGFR, the receptor starts a complex chain of biochemical reactions inside the cell that signals the cancer cell to reproduce. Erbitux blocks EGFR, interrupting a signal to reproduce which can stop the growth of colorectal cancer cells. However, when colorectal cancer cells have a mutation in the KRAS gene, they continue to reproduce even when Erbitux blocks EGFR.
The FDA first approved Erbitux in 2004 to treat EGFR-expressing late-stage colorectal cancer after patients stopped responding to chemotherapy. In 2009, the FDA approved updated recommendations for Erbitux, based on studies that found the drug is not effective in patients whose tumors have a mutated KRAS gene.
The therascreen KRAS RGQ PCR Kit was developed by QIAGEN Manchester Ltd., of Manchester, England.
Erbitux is co-marketed by New York City-based Bristol-Myers Squibb and Eli Lilly and Co. of Indianapolis.
— The Food and Drug Administration