Bias Seen in Some Avandia StudiesFeb 24, 2010 | Parker Waichman LLP
Have the financial relationships between the drug industry and medical researchers influenced findings in Avandia studies? A new analysis of such research indicates that they have.
Avandia’ label has borne a black box warning – the Food & Drug Administration (FDA’s) strongest safety warning – detailing its possible association with myocardial ischemia since 2007. As we reported over the weekend, a two-year investigation of Avandia by the Senate Finance Committee found that in July 2007 the FDA’s own scientists estimated that Avandia was responsible for more than 80,000 heart attacks. According to the report, two of the FDA’s own doctors wrote in an October 2008 memo that Avandia should be removed from the market because it poses serious heart-related dangers to patients. The report included emails from GlaxoSmithKline officials and drew on interviews with Glaxo and FDA officials and anonymous whistleblowers.
This new analysis of Avandia research papers is only going to add to the controversy surrounding the drug. According to a report on TheHeart.org, the Avandia study was presented as a poster by Dr Mohammed Hassan Murad of the Mayo Clinic at the American College of Preventive Medicine’s (ACPM) annual meeting.
Murad and colleagues performed a review of 202 articles that addressed the possible association between the risk of heart attacks and use of Avandia in diabetes patients. Of the articles reviewed, 107 (53%) included a conflict-of-interest statement and 90 (45%) had a conflicting financial relationship. Two reviewers who were blinded to the authors’ financial relationships evaluated each article and classified it as being favorable (supporting the argument that the drug does not increase the risk of heart attack), neutral, or unfavorable (questioning Avandia’s safety), TheHeart.org said.
Ninety-one percent of the authors who reached favorable conclusions on Avandia and heart risks had financial relationships with antihyperglycemic agent manufacturers. What’s more, 86% had a financial relationship with GlaxoSmithKline, the maker of Avandia. Contrast this with the authors who presented unfavorable conclusions: Only 5% had financial relationships with antihyperglycemic agent manufacturers and 18% had such a relationship with Glaxo that was disclosed.
However, Murad and colleagues also found through an online search that some authors listed financial conflicts in other publications that were not disclosed in their Avandia paper, TheHeart.org said.
Since the release of the Senate report, calls have increased for FDA to pull Avandia off the market. Earlier this week, the FDA said it would again review Avandia for heart risks. According a notice posted on the FDA’s Web site, the agency is reviewing the primary data from a Glaxo-funded study called RECORD, as well as a number of observational studies of the cardiovascular safety of Avandia that have been published. The results of the review will be discussed at a public meeting in July, the FDA said.