FDA Panel Asked To Consider Avastin's Use In Breast Cancer
First Published Tuesday, 20th July 2010 08:44 pm - © 2010 Dow Jones
By Jennifer Corbett Dooren
Of Dow Jones NEWSWIRES
WASHINGTON -(Dow Jones)- A Food and Drug Administration panel is being asked to weigh whether Roche Holding AG's (RHHBY, ROG.VX) top-selling cancer drug, Avastin, should continue to be marketed for use in breast cancer.
Avastin is approved to treat several types of cancer, including colon, lung and kidney cancer, and had global sales of nearly $6 billion last year. Analysts estimate if the breast cancer indication were to be removed it could cut about $1 billion off annual sales.
The FDA in 2008 approved Avastin, under a mechanism known as accelerated approval, to treat the most common type of advanced, or metastatic, breast cancer in combination with the chemotherapy drug paclitaxel. That accelerated mechanism allows the drugs to be approved based on initial positive studies. For full approval, companies then have to submit additional data, which Roche's Genentech unit did last year.
Along with asking the FDA to convert Avastin's accelerated approval to regular approval, Genentech is seeking FDA approval for Avastin's use in combination with other types of chemotherapy drugs.
However, the FDA has questioned whether the benefit of Avastin shown in the two additional studies is clinically meaningful and is asking its oncology drugs panel for advice.
The original study that supported Avastin's accelerated approval showed adding the drug to paclitaxel added 5 1/2 months to median progression-free survival, or the average amount of time patients lived without the cancer getting worse. The new studies show a smaller impact on progression-free survival.
Richard Pazdur, the director of the FDA's oncology products office, said Avastin was "associated with considerable toxicity." He noted that no study has shown Avastin prolongs overall survival, although the studies have shown an improvement in so-called progression-free survival, or the time before cancer starts growing again.
Many cancer researchers have argued that it's difficult to demonstrate an improvement in overall survival among patients with advanced cancer and that looking at a drug's impact on progression-free survival is a better measure of a treatment effect.
The FDA's panel of non-FDA medical experts is being asked to vote later Tuesday on whether it thinks the two studies show a "favorable-risk benefit" for Avastin and whether the data provide confirmation of Avastin's benefit seen in the original study. The panel is also being asked whether Avastin's indication for the treatment of metastatic breast cancer should be removed.
The FDA said the additional two studies "failed to confirm the magnitude" of the benefit in the first study that supported Avastin's approval. One study showed women lived less than a month longer without their disease progressing compared with women not receiving the drug as part of their treatment, while the other study showed a difference of no more than 2.9 months, the FDA said. The agency also said there were more serious side effects, such as bleeding among women being given Avastin.
Sandra Horning, a Genentech senior vice president, said the data shows a "reliably consistent and significant improvement" in progression-free survival.
"We believe that Avastin combined with chemotherapy is an important option for physicians and metastatic breast cancer patients to consider," she said.
The FDA will take the panel votes into consideration as it weighs Avastin's fate. The options include requiring additional studies of Avastin in breast cancer, or removing the breast cancer indication entirely. The agency could also decide to grant full approval of Avastin as well as allow its use in combination with other chemotherapy drugs. A decision in expected in September.
Avastin is designed to inhibit tumors by interfering with a protein that forms blood vessels in the tumors. Chemotherapy is an older, standard treatment for cancer that kills cancer cells, but it also kills healthy cells throughout the body.
Avastin is usually given in combination with chemotherapy drugs.
-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; firstname.lastname@example.org