July 17, 2010

Breast Cancer Drug Proves Ineffective

Federal health scientists said Friday that follow-up studies of a Roche breast cancer drug showed it failed to slow tumor growth or extend patient lives.

The Food and Drug Administration approved Roche's blockbuster Avastin in 2008 based on early-stage trials after it was seen that it shrank tumors caused by breast cancer.  The decision was controversial because drugs for cancer patients who have never been treated before must show evidence that they extend lives.

Avastin's so-called "accelerated approval" was based on the condition that later studies could prove a survival benefit.

However, FDA reviewers said two follow-up studies recently submitted by Roche failed to show that the drug "significantly extended lives compared to chemotherapy alone."

The FDA also said that more recent data did not confirm the tumor shrinkage seen in earlier studies.

Patients that took Avastin showed significantly more side effects, such as high blood pressure, fatigue and abnormal white blood cell levels.

The FDA will ask a panel of outside cancer experts on Tuesday to review the evidence on Avastin.  The panel's recommendations are not binding, but the FDA usually follows their guidance.

The FDA has the ability to remove the drug's approval for breast cancer.

Avastin is also approved for colon, lung, kidney and brain cancer.  The drug was Roche's top-selling cancer treatment last year.

Roche is headquartered in Basel, Switzerland, and its biotech unit Genetech is based in South San Francisco.

Avastin was the first drug to fight cancer by stopping nutrients from getting to tumors.  It was believed that these types of "targeted therapies" held promise for eliminating chemotherapy.  However, the two approaches are now used in combination.

The FDA has granted acceleration approval to drugs based on so-called surrogate endpoints since 1992.  For cancer drugs, tumor shrinkage is considered a predictor of increased survival.

Drugmakers favor the program because it helps them put their products on the market faster.

However, the program has not escaped criticism from government watchdogs.

The Government Accountability Office (GOA) issued a report last fall that said the FDA should do more to determine whether drugs approved based on preliminary results actually live up to their promise.

The GOA said the FDA has never once pulled a drug off the market because of missing or unimpressive follow-up data.


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