The US Food and Drug Administration yesterday approved a new type of cancer drug, which works by preventing the growth of new blood vessels that feed tumors. Avastin was approved for use in conjunction with standard chemotherapy for patients with colon cancer that has spread to other parts of the body.
In tests that led to the FDA action, the drug extended the lives of patients with the deadly cancer by about five months on average.
"The approval of Avastin is the result of many years of research and development exploring a promising new approach to fighting cancer," said Dr. Mark B. McClellan, the FDA commissioner, in a statement. He said the drug, along with several other new treatments, significantly improves doctors' ability to treat colon cancer, which afflicts about 150,000 Americans a year and now kills about 57,000.
Avastin grew out of a new cancer-fighting theory first proposed in 1970 by Dr. Judah Folkman, a surgeon at Children's Hospital Boston. In 1983, Dr. Harold Dvorak of Beth Israel Deaconess Medical Center identified a protein in the body that seemed to allow tumors to tap into blood vessels. Six years later, Genentech scientist Napoleone Ferrara cloned the protein, which he called vascular endothelial growth factor, and discovered that it actually spurs growth of blood vessels around tumors. Company scientists then genetically engineered an antibody that attaches to the growth factor and stops it from working. The drug essentially starves the tumor.
Speaking of Genentech's work, Ferrara said, "It is almost incredible that work initiated over 15 years ago, trying to isolate a protein from pituitary cells, may have led to Avastin. The thought that Avastin may help alleviate some suffering is great."
Ferrara said Genentech is now focused on examining other uses for Avastin, both in cancer and in many other diseases characterized by abnormal growth of blood vessels. Scores of similar drugs are being developed by pharmaceutical and biotechnology companies across the country.
"Avastin turns a theory into a therapy," said Folkman. "That's exciting to see. I'm very proud of this effort."
Avastin is already in late-stage clinical tests for cancer of the lung, kidney, and breast, and is being tested with other combinations of chemotherapy for colon cancer. So far, the drug has not worked as well in late-stage breast cancer patients.
In the tests that led to Avastin's approval, only 45 percent of patients responded to treatment with Avastin, but that was better than the 35 percent who responded to standard chemotherapy.
Company officials said the drug, which is administered intravenously, would be sold for $4,400 per month.