Safety of diabetes drug Avandia debated by federal scientists
Tuesday, July 13, 2010; 6:03 PM
Federal scientists disagreed sharply Tuesday about whether the diabetes drug Avandia is unsafe and should be removed from the market.
The conflicting analyses were presented during the opening day of a two-day meeting of scientific advisers that the Food and Drug Administration convened in Gaithersburg to evaluate the diabetes drug.
Approved in 1999, Avandia quickly became the world's most popular drug to treat Type 2 diabetes, which is the most common form of the disease. But in 2007, Cleveland Clinic cardiologist Steven E. Nissen published a study that concluded that the drug significantly increased the risk for cardiovascular problems, the leading cause of death among diabetics.
Sales of Avandia plummeted, and the FDA issued strong new warnings about the drug's safety. But after a panel of advisers voted later that year to keep the drug on the market, the FDA decided not to pull it.
Critics said the decision illustrated the agency's failure to protect the public from dangerous drugs, especially in the wake of high-profile drug safety concerns about the painkiller Vioxx and other medications.
There also have been allegations that GlaxoSmithKline, which makes Avandia, knew about the risks but hid them.
During Tuesday's hearing, the FDA's Thomas A. Marciniak presented a detailed critique of a study GlaxoSmithKline sponsored and has held up as the best evidence of the drug's safety. Marciniak said the company excluded important details about patients that would have shown that the drug increased the risk for heart attacks. Kate Gelperin, another FDA scientist, presented an analysis that concluded that Avandia increased the risk for heart attacks, heart failure and death.
But in an unusual display of conflict within the agency, other FDA researchers challenged Marciniak's analysis of the pivotal study, known as Record. Ellis F. Unger, for example, questioned Marciniak's interpretations of how the data were selected and agreed with the company's argument that the study showed the drug was safe. GlaxoSmithKline's Murray Stewart also defended the drug, arguing that other studies have found no increased risks.
The 33-member panel will vote Wednesday on a series of questions, including whether to allow Avandia to stay on the market, whether it should be removed and whether a study aimed at comparing Avandia to another diabetes drug should proceed.
FDA Commissioner Margaret A. Hamburg, who was named to the post last year by President Obama, will make the final decision. FDA commissioners usually follow the advice of their expert panels, but they don't have to. Hamburg has pledged to make drug safety a priority. Many observers are watching what the agency does about Avandia as a potentially defining moment for the FDA under the new administration.