Avastin Raises Heart Failure Risk
Women
with advanced breast cancer who were treated with Roche's Avastin were more
likely to develop heart failure than other women, according to an analysis released
on Tuesday that raised more concerns about the already troubled drug.
A team led by Dr. Toni Choueiri of Dana Farber Cancer Institute
and Harvard Medical School in Boston analyzed data on advanced breast cancer
patients from five clinical
trials.
They found that 1.6 percent of the women who took Avastin
developed congestive
heart failure compared with 0.4 percent of women who got a placebo.
"Overall,
the risk is small, but it is definitely more than the placebo," Choueiri
said in a telephone interview.
He
said the findings, published in the Journal of Clinical Oncology, add to concerns
about Avastin, the world's best-selling cancer
medicine with annual sales of $6 billion.
Last
month, U.S. regulators recommended that Avastin should no longer be approved
for breast cancer. European authorities recommended restricting its use in
breast cancer for only one type of chemotherapy.
Avastin, or bevacizumab, has been approved for fighting breast and other cancers, but the drug failed to extend survival in four clinical trials of patients with breast cancer.
Roche's
Genentech unit said in a statement heart failure is not a new safety signal for
Avastin and is already made clear on the drug's prescribing information.
Choueiri
said his study is the first to show the drug increases the risk of heart
failure in breast cancer patients.
His
team analyzed results of five clinical trials involving nearly 4,000 women with
advanced breast cancer that collected data on heart failure. Three of the
studies were published in peer-reviewed medical journals, while two were presented
at a breast cancer conference.
He
said there was a statistically significant increase in heart failure in women
who were treated with Avastin.
That
may be due in part to the way the drug works. Avastin blocks vascular
endothelial growth factor, or VEGF, which is needed to form blood vessels to
feed tumors.
But
VEGF is also needed to maintain the heart's structure, Choueiri said, and it
may be that blocking VEGF is having a negative effect on women with breast
cancer, whose hearts may have already been compromised by other cancer
treatments.
Drs.
Nitin Verma and Sandra Swain of Washington Cancer Institute and Washington
Hospital Center said in a commentary the results should be interpreted with
"extreme caution."
They
said the analysis adds little to what has already been known about the heart
failure risk associated with breast cancer patients taking Avastin.
Many
breast cancer groups and U.S. lawmakers expressed outrage at the FDA's decision
on Avastin, charging the agency based its decision on cost, something the FDA
is forbidden from doing.
Avastin
costs about $8,000 a month in the United States, although Roche caps the annual
price at $57,000 per patient.
The
company has asked the FDA to reconsider its decision on the drug. Doctors can
still prescribe Avastin for breast cancer, but without FDA approval, insurance
companies are less likely to pay for it.
"Genentech
continues to believe Avastin is an important option for women with metastatic
breast cancer," the company said.
...
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