JULIA MEDEW – February 22, 2010 – The Age
Australian authorities are closely monitoring a common diabetes drug after allegations its manufacturer, GlaxoSmithKline, knew of heart attack risks years before evidence of a link became public.
A spokeswoman for the Therapeutic Goods Administration said yesterday that it was waiting to see how the US Food and Drug Administration reacted to a US Senate report released on Saturday that highlighted safety concerns about the drug, commonly used to treat type 2 diabetes.
The TGA spokeswoman said it had strengthened warnings about the drug’s side effects several times since 2007, and that as of October last year, there were about 80,000 Australians using the drug. ”The TGA is monitoring this medicine and will look at any action taken by the FDA”, she said.
The Senate report, which followed a two-year inquiry, said GlaxoSmithKline knew of possible heart attack risks tied to Avandia – also known generically as rosiglitazone in Australia – years before such evidence became public. The US senators who released the report, Max Baucus and Chuck Grassley, are also asking the FDA why it allowed a clinical trial of Avandia to continue even after the agency estimated that the drug caused 83,000 heart attacks between 1999 and 2007.
Both the FDA and the TGA in Australia ordered warnings to be included on Avandia’s label in 2007, saying that it might increase the risk of heart attacks, though the data on the risk was inconclusive.
Soon afterwards, Senator Grassley disclosed that the FDA’s own safety experts came within one vote of recommending a withdrawal of Avandia.
The Senate report suggests sharp disagreements remain at the FDA over how to handle Avandia’s risks.
In a letter to FDA commissioner Margaret Hamburg also released on Saturday, the senators said their report was based on studies of Avandia, internal GlaxoSmithKline documents and FDA documents. Investigators had also interviewed GlaxoSmithKline and anonymous whistleblowers.
Based on its knowledge of heart attack risks, GlaxoSmithKline ”had a duty to sufficiently warn patients and the FDA of its concerns in a timely manner”, the report said. Instead, the company tried to play down findings the drug could increase cardiovascular risks, it said.
GlaxoSmithKline said in a statement that the drug was safe. It said the committee report took data out of context.
In May 2007, The New England Journal of Medicine published an analysis of dozens of studies on nearly 28,000 people who had taken Avandia. The journal said there was a 43 per cent higher risk of heart attack for those taking Avandia compared with people taking other diabetes drugs or no diabetes medication.
The findings raised concerns because two-thirds of the people with type 2 diabetes die of heart problems.
”Contrary to the assertions in the report, and consistent with the FDA-approved labelling, the scientific evidence simply does not establish that Avandia increases cardiovascular ischaemic risk or causes myocardial ischaemic events,” GlaxoSmith Kline said.
FDA spokesman George Strait said the agency was reviewing new data.
Deputy president of the Australian Medical Association Dr Steve Hambleton said he was confident the TGA would manage safety concerns appropriately.