By: Patrick Totty
A U.S. Senate Finance Committee report released on February 20 says that Avandia, GlaxoSmithKline’s drug for type 2 diabetes, may have caused as many as 83,000 heart attacks between 1999, when the drug was introduced, and 2007. The Senate report, culminating a two-year inquiry into the drug, also says that Glaxo knew about the drug’s potential risks years before suspicions began to form regarding a connection between Avandia and heart problems.
The report, released under the names of Senators Max Baucus (D-Mont.) and Charles Grassley (R-Iowa), also questioned why the Food and Drug Administration allowed Glaxo to begin a six-year clinical comparison of Avandia to its commercial rival Actos in 2007, even after years of evidence had accumulated that Avandia seemed to increase the risk of heart attack and heart failure. Glaxo’s study, still underway, will eventually enroll 16,000 patients. In the meantime, Glaxo has defended Avandia, saying that the Senate committee took FDA data out of context and that the evidence does not establish increased cardiovascular risks.
According to the Senate report, 500 heart attacks and 300 instances of heart failure could be averted each month if patients currently taking Avandia switched to Actos, a drug manufactured by the Japanese pharmaceutical company Takeda. (In its story on the Senate report, the New York Times said that the FDA had evidence that linked Avandia to 304 deaths during the third quarter of 2009.)
Avandia is the commercial name for rosiglitazone, a member of the family of anti-diabetes drugs known as thiazolidinediones (TZDs), drugs that increase the body’s sensitivity to insulin. Actos, the commercial name for pioglitazone, is also a TZD. Both drugs carry warnings about possible side effects on patients’ hearts, but Actos has not generated the same level of concern.
Glaxo’s top year with Avandia was in 2006, when it sold more than $3 billion worth of the drug. By 2009, after reports began emerging about its possible link to increased risk of heart attack, sales dropped to $1.2 billion. (In contrast, sales of Actos from April 2008 through March 2009 were $4.4 billion.)
The FDA is now reviewing data on Avandia and will present its findings this summer to an advisory board that will decide whether Avandia can stay on the market. In 2007, when concerns that Avandia might cause harm to patients’ hearts were becoming public, an FDA oversight board voted eight to seven to allow the drug to remain on the market, but also ordered the agency to issue a warning. That warning was followed the next year by Avandia’s dramatic drop in sales.
The Senate report is posted here.
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