Mixed Criticism on Avandia Effectiveness

GlaxoSmithKline’s diabetes drug Avandia (rosiglitazone) stirred up a ton of news this week, as multiple studies were released, variously touting and trampling the embattled drug.

According to a study issued on Monday, patients taking Avandia have a higher risk of death, heart failure, and stroke than those taking Teva’s Actos. This study comes a scant two weeks before an FDA advisory panel is slated to decide the fate of GSK’s blockbuster drug, which has been under fire since similar results were revealed in a 2007 study.

But that’s not the last word. Complicating the matter are volumes of data for and against the drug. A second study, also released at the American Diabetes Association’s meeting on Monday, tells a different tale.

A post-trial study of 2,368 diabetes patients by the Washington University School of Medicine showed “no increased rate of heart attack or death” in patients treated with Avandia. The analysis went one step further by claiming that researchers actually showed that the drug reduced the rate of death, heart attack, and stroke against patients not taking the treatment.

In a press statement, GlaxoSmithKline maintains that it is aware of all the studies regarding Avandia, and recognizes the “strengths and limitations of each type of analysis that must be factored into their evaluation.”

“Randomized clinical trials remain the gold standard for evaluating scientific and medical questions,” stated Mary Anne Rhyne, director of GSK’s US media relations. “Results from six controlled clinical trials (RECORD, APPROACH, VICTORY, VADT, ACCORD and BARI-2D) have been reported since the Joint Advisory Committees reviewed questions about the cardiovascular safety of Avandia in 2007. Taken together, these trials show that Avandia does not increase the overall risk of heart attack, stroke, or death.

“GSK also has updated its prior meta-analysis to include data from 52 clinical trials and it does not show an increase in myocardial ischemia,” Rhyne continued. “There also have been several new observational studies published since 2007. Review of these studies with tighter confidence intervals have risk ratios that are very close to one, indicating no difference in the risk of myocardial infarction between rosiglitazone and pioglitazone.”

In 2007, an FDA review panel voted 22–1 to keep Avandia on the market. Since then, the number of people calling for FDA to stop the sale of the drug has grown, and a new administration in the White House might sway sentiment against the drug company. The FDA advisory panel is scheduled to meet on July 13.

Sales of Avandia were $3.2 billion in 2006, but have declined to about $1.2 billion since then.