GlaxoSmithKline has again sprung to the defence of Avandia and issued a 30-page rejection of claims made in a US Senate report which called for the withdrawal of the controversial diabetes drug.

The company was responding to Senate Finance committee report based on a two-year inquiry of Avandia (rosiglitazone), prompted by the publication in May 2007 of a meta-analysis in the New England Journal of Medicine which warned of the possible cardiovascular risk of the drug (see links below). In a ‘White Paper,’ GSK says the report “fails to present an accurate, balanced or complete view of the currently available information on Avandia” and “rejects any allegations of concealing safety information or acting inappropriately on behalf of patients”.

GSK goes on to say that “among its most glaring omissions”, the report does not include discussion of the final results of either the ADOPT, DREAM, or RECORD studies. The first two trials and the interim data for RECORD were evaluated by an independent US Food and Drug Administration advisory board in 2007, GSK notes, which voted 22-1 in favour of keeping Avandia available for patients.

The company argues that “RECORD provides the best, most reliable assessment of Avandia’s cardiovascular safety”, adding that the report also fails to mention “multiple other studies that all corroborate the ischaemic cardiovascular safety of rosiglitazone”. GSK goes on to say that “instead of reviewing the most recent and scientifically sound information”, the report relies on the aforementioned meta-analysis prepared by Steve Nissen in 2007, “an analysis which has been criticised widely, and contradicted by larger, more recent meta-analyses”.

The suggestion in the report that GSK did not actively monitor the safety of Avandia or inform the FDA of its investigations “is fundamentally flawed and contradicted by a record of extensive, on-going interactions” between the company and the agency, the company says. GSK concludes by saying that it “stands behind the safety of Avandia [and] welcomes the opportunity for an independent and scientific evaluation of the collective safety of rosiglitazone” at the upcoming FDA advisory committee in July.