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Sunday, 20 November 2011

FDA withdraws approval of Avastin to treat breast cancer

Despite the return of an aggressive, incurable form of breast cancer, she is still kicking, and she credits Avastin - a medication the Federal Drug Administration revoked its approval for on Friday.


"It's just devastating," Turnage, 49, said of the FDA's decision. "It's very sad."


FDA Commissioner Dr. Margaret Hamburg explained the decision, saying that the drug has not been shown to be safe and effective for the treatment of breast cancer.


After reviewing the available studies it is clear that women who take Avastin for metastatic breast cancer risk potentially life-threatening side effects without proof that the use of Avastin will provide a benefit, in terms of delay in tumor growth, that would justify those risks. Nor is there evidence that use of Avastin will either help them live longer or improve their quality of life," she said in a statement.


The National Breast Cancer Coalition also does not support use of the drug as a metastatic breast cancer treatment.


But Turnage and others who suffer from the disease say Avastin has been a "miracle drug" for them.


"(The FDA's decision) is a death sentence for some," Turnage said.


Turnage, who worked as a nurse before retiring because of her illness, has triple-negative breast cancer - a rare but highly aggressive form of the disease.


The FDA approved Avastin for metastatic breast cancer in 2008 after a study in the New England Journal of Medicine showed that patients who took it in conjunction with a chemotherapy drug experienced six more months of progression-free survival than patients who took only the chemo drug. It was the first medicine to be OKd under an accelerated approval program that allowed it to be used while researchers gathered additional data to clarify its safety and efficacy.


The approval was controversial at the time, since an FDA advisory panel had voted against the drug in a 5-4 decision just a few months earlier.


Two subsequent studies showed that Avastin seemed to slow tumor growth significantly in breast cancer patients but did not extend survival.


That soured experts charged with monitoring new data on the drug's pros and cons. The FDA moved to withdraw Avastin's approval for breast cancer patients in December 2010, but the drug's manufacturer, Genentech Inc., challenged the agency.


Medications that are fast-tracked require rigorous continued review, and "withdrawal is an essential component of the accelerated approval program," Hamburg said.


Avastin's ability to help patients with advanced breast cancer live longer has always been in doubt, and few experts expressed surprise at the FDA's action.


"It does not improve survival," said Dr. Joanne Mortimer, director of the Women's Cancers Program at City of Hope in Duarte, who served on two of the three FDA advisory panels that debated Avastin's use for breast cancer. "Yes, it keeps your cancer under control longer. But … the risks are pretty huge."


Studies showed that women with advanced breast cancer taking Avastin had a higher risk of death from stroke or heart attack, and that the medication raised blood pressure and increased the risk of congestive heart failure. The risk of serious bleeding was five times higher among users of Avastin than it was for those on chemotherapy only.


Hopes that Avastin could prolong life for patients with advanced breast cancer rested on a 2007 study in the New England Journal of Medicine. Researchers found that patients who took the drug in combination with the chemotherapy agent paclitaxel experienced an 11.8-month window, on average, during which their cancer was not growing. That compared with an average of 5.9 months of progression-free survival in patients receiving standard chemotherapy alone.


But even in that study, patients on Avastin did not live longer, said Dr. Kerin Adelson, a medical oncologist at Mount Sinai School of Medicine in New York.


A later study confirmed Avastin's failure to extend survival, and brought the drug's risks into better focus, Adelson said. (One of her own breast cancer patients who took Avastin had a massive stroke, she said.)


"Many drugs will improve the amount of time it takes for a cancer to grow but don't improve the amount of time a patient lives," she said. "For Avastin, that was the situation."


The drug generated about $3.5 billion in sales in the United States in 2010. But sales have fallen this year since the FDA advisory committee recommended that approval for breast cancer patients be withdrawn. It's not known how many U.S. patients with breast cancer took the drug, but doctors said it was commonly prescribed in cases of metastatic disease.



Tags: 2 new breast cancer drugs,  Breast cancer patientsBone drug breast cancer,

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