New evidence suggests the risks outweigh the benefits of Avastin for treating metastatic breast cancer, according to officials at the U.S. Food and Drug Administration. The agency has now begun the process of withdrawal of the popular advanced breast cancer treatment.
The FDA granted an accelerated conditional approval for Avastin in February 2008 to treat late-stage breast cancer patients. The drug, it had been suggested, slowed the progression of the disease or improved overall survival.
But results from four new trials that enrolled more than 3,000 women found no significant reduction in disease progression or death among those who took Avastin along with chemotherapy.
"These trials were intended to confirm progression-free survival, and they did not," Dr. Janet Woodcock, director of the FDA's Center of Drug Evaluation and Research, said at a news conference. "There was no symptomatic benefit and no effect in overall survival."
Avastin is still available to patients, but the announcement is the beginning of a regulatory withdrawal of the drug from the market. And some cancer specialists say the basis of the announcement has huge implications for the way their patients will be treated.
"This decision removes an option for patients," said Dr. Edith Perez, clinical oncologist at Mayo Clinic.
According to American Cancer Society's deputy medical officer Dr. Len Lichtenfeld, the FDA's announcement "will come as a disappointment to many breast cancer patients who may have benefited from the drug."
Some doctors even reported seeing a benefit in their patients who took Avastin.
"We will be working hard to make sure that patients who are getting Avastin and seeing good control of their cancer, will continue to get Avastin with their treatment," said Dr. Gretchen Kimmick, medical oncologist at Duke University Medical Center.
Still, the studies showed no overall benefit from the drug, and even suggested some patients had an increased risk of death because Avastin is, in some ways, toxic.
"We don't doubt that this drug provides a response to the breast cancer, but it doesn't translate to prolonging survival," said Woodcock, who agreed that in some individualized cases Avastin may have helped patients manage their breast cancer.
However, it is unknown which women may benefit from the drug while others do not.
"We would encourage at this time patients to discuss with their physician what the appropriate action should be," said Dr. Richard Pazdur, director of the FDA's Office of Oncology Drug Products.
The agency sent a letter to Avastin's manufacturer, Genentech, offering the company 15 days to request a public hearing where a non-voting advisory committee will review the data and provide recommendations to the commissioner.
"We believe women living in the United States with metastatic HER2-negative breast cancer should also have Avastin as a treatment option, and, therefore, we will request a hearing with the FDA," Dr. Hal Barron, chief medical officer and head of global product development at Genentech said in a written statement.
Should Genentech move forward to request a hearing, it will be the first time a manufacturer chose not to withdraw an accelerated approved drug voluntarily, according to Dr. Patricia Keegan, director of the FDA's Division of Biologic Oncology Products.