FRIDAY, July 1, 2011 (HealthDay News) -- Oncologists and even some breast cancer support groups are endorsing a U.S. health advisory panel's recommendation that the blockbuster cancer drug Avastin be removed for use in metastatic breast cancer.
The reason: There's still a lack of understanding of how the drug works or who it helps.
Avastin was given fast-track approval by the U.S. Food and Drug Administration in 2008 to be used, in combination with the chemotherapy drug Taxol, by women with metastatic HER2-negative breast cancer.
But a six-member FDA panel of cancer experts said Wednesday that the drug was not effective, caused dangerous side effects and its approval should be revoked.
The decision, which is non-binding, came at the end of a two-day hearing granted to Avastin maker Genentech after the FDA recommended last December revoking the drug's approval for metastatic breast cancer. The FDA cited the medication's poor performance in follow-up studies and its potential for serious side effects.
Karuna Jaggar, executive director of Breast Cancer Action, told HealthDay that "the panel made the right decision. We have been advocating for the FDA to take a critical stand on Avastin and really focus on overall survival," which hasn't been proven by any of the drug's studies so far.
Dr. Paula Klein, an oncologist specializing in breast cancer at Beth Israel Medical Center in New York City, said there may well be a subset of women for whom Avastin will extend life. But she faulted the drug maker for not trying to identify that group. "What Genentech has failed to do is spend the money necessary to find the subset of breast cancer patients that will benefit," she said.
Jaggar said she wished the evidence supporting Avastin had been stronger. She said she would support having Genentech doing a trial to try to identify women who would benefit from the drug. To date, any benefit from the drug has been based on anecdotal reports.
"But in the meantime, we do not believe Avastin should retain its approval on the hope we will eventually learn there are some women who do benefit from this treatment," Jaggar said. "We can't keep drugs on the market while we wait to see if they are effective."
Dr. Marc E. Lippman, deputy director of the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine, said he, too, supported the panel's decision. "I think they did a wise thing," he said.
But Lippman added that women should not stop taking Avastin based on the panel's recommendation. "I wouldn't, in my right mind, recommend discontinuing the drug from someone who is currently benefiting. It would be insane to stop the drug," he said.
And Klein said: "To women who are currently on the drug with advanced disease [and] doing well, you'd have to comfort them that there is a very good possibility that they will continue to do just as well with chemotherapy alone, if Avastin is no longer available. There is certainly a possibility of that."
In each trial of Avastin reviewed by the advisory panel, women who took the drug were also receiving chemotherapy, so it wasn't clear whether it was Avastin or the chemotherapy that was preventing their cancer from progressing. The trials also showed no benefit from the drug in extending life, despite the risk of serious side effects, including death.
"The gold standard has always been overall survival," Klein said. "This is one of the few drugs that was granted accelerated approval based on progression-free survival."
The hope was that studies would show the drug could extend overall survival, not just progression-free survival, Klein added, "but they failed to do it."
The advisory panel's decision now goes to FDA Commissioner Margaret Hamburg, who won't address the issue until the period for public comment ends July 28. Even if she revokes Avastin's use as a breast cancer drug, however, it will not be taken off the market because it is also used for advanced colon, lung, kidney and brain cancer.
And oncologists will still have the option of prescribing Avastin "off label" to their patients with metastatic breast cancer.
But Lippman noted that any FDA revocation of the drug's approval might prompt insurance companies to stop paying for Avastin, which can cost $80,000 a year. "I hope there would be some recommendation around that," he said.
Meanwhile, on Thursday, Don McLeod, a spokesman for the Centers for Medicare & Medicaid Services, said Medicare will continue to pay for the drug as a breast cancer treatment even if the FDA withdraws that approval.
However, Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City, said even the panel's recommendation may make some doctors less willing to prescribe Avastin.
"The hope is that patients getting the drug who are having a good response will still have access to the drug. And, that's what's being put in jeopardy," she said.
In the midst of all the action and reaction in the United States, pharmaceutical giant Roche, which owns Genentech, announced on Thursday that the European Commission had just broadened Avastin's existing use in metastatic breast cancer, allowing it in tandem with the chemotherapy drug Xeloda.
For more on breast cancer, visit the U.S. National Cancer Institute.