Avastin, Erbitux Combo Proves DangerousFeb 5, 2009 | Parker Waichman LLP
Combining Avastin and Erbitux with chemotherapy to treat colon cancer may actually make patients sicker, and cause their tumors to grow faster. According to a new Dutch study, using Avastin and Erbitux to increase the effectiveness of chemotherapy is a complete failure, and could actually cut the survival time of patients by as much as a month.
Avastin was approved by the Food & Drug Administration (FDA) in 2004 to treat colon cancer, and in 2006, the agency approved it as a treatment for non-small cell lung cancer. Last year, the FDA also approved Avastin as a breast cancer treatment. Avastin was the first approved therapy designed to inhibit angiogenesis, the process by which new blood vessels develop and carry vital nutrients to a tumor.
Erbitux is indicated for the treatment of patients who have colorectal cancer that has spread to other parts of the body and whose tumor expresses a protein called an Epidermal Growth Factor Receptor. Erbitux was approved by the FDA to treat advanced colon cancer in 2004, and again in 2006 for treating squamous cell carcinoma of the head and neck
It was theorized that adding Erbitux and Avastin to chemotherapy could boost benefits, but unfortunately, the Dutch study has proven the opposite to be true. The study looked at 732 patients; 378 patients where treated with chemo plus Avastin. The remaining patients received chemo along with Avastin and Erbitux.
Median progression-free survival was 10.7 months among those receiving only Avastin with their chemo. That figure dropped to 9.4 months in patients treated with both Avastin and Erbitux. Likewise, median over-all survival in the Avastin plus chemo group was 20.3 months, but fell to 19.4 months in those who received both drugs with chemo.
The combo also appeared to have caused more adverse effects among patients, primarily skin conditions. Nearly twice as many patients given the Avastin - Erbitux company reported skin problems, with an acne-like rash being the most common.
This is not the first time an Avastin drug combo has disappointed. Last summer, trials involving the use of Avastin with Sutent - one of the most widely used medicines for the treatment of advanced kidney cancer - was stopped after patients developed a dangerous type of anemia.
Avastin has been linked to other safety worries. When the FDA approved Avastin for breast cancer patients last year, it did so against the recommendation of its own advisory panel. In late 2007, the panel voted 5-4 to recommend that the agency reject Genentech’s application to expand the approved uses of the drug to include advanced breast cancer.
The FDA advisory panel vote came after agency staffers posted documents on the FDA website noting that while Avastin did extend the period prior to patients’ breast cancer becoming worse, treatment with the drug did not markedly increase survival time. The FDA documents also pointed out that Avastin caused serious side effects, including cardiovascular problems, bowel perforations, and a few deaths. The FDA staff said that those side effects included several patient deaths that were “probably or definitely” due to Avastin.
Last June, researchers at Stony Brook University Cancer Center in New York released a study of an analysis of 15 clinical trials involving nearly 8,000 patients that indicate those taking Avastin were at a higher risk of blood clots. The Stony Brook study showed that about 12 percent of people who took Avastin developed blood clots in the veins, a rate that’s about 30 percent higher than among other cancer patients who are not taking it. These types of blood clots put patients at a higher risk of death, because they can travel to the lungs. Clots are already a common problem faced by cancer patients.
In December, Genentech also reported that some Avastin patients had experienced eye inflammation when it was used off-label to treat an eye condition.