Avastin has been linked to 36 cases of eye inflammation, Genetech recently reported. The inflammation occurred when Avastin was used to treat an eye condition, an unapproved use of the drug.
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. Earlier this year, the FDA 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.
According to Genentech, its partner Roche Holding AG received 38 reports of eye inflammation linked to Avastin between November 4th and 20th, 2008, from four different reporting sites. According to Genentech, 32 of the cases were serious. In all of the cases, Avastin was being used off-label to treat wet macular degeneration, which can cause blindness.
Genentech sells another drug, Lucentis, which is similar to Aventis, to treat the eye condition. Apparently, some doctors have been dividing Aventis into multiple doses in order to use it as a low-cost alternative to Lucentis. Similar cases of eye infections are reported in about 2 percent of Lucentis patients, Genentech has said.
A Genetech spokesperson told Reuters.com that 25 of the eye inflammation cases came from one single lot of Aventis. A lot consists of 66,000 single-use vials.
Avastin has been linked to other safety worries. When the FDA approved Avastin for breast cancer patients earlier this 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 month, 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.