Almost all — some 94 percent — of the researchers who published favorable medical journal studies and commentaries on the controversial diabetes drug rosiglitazone had financial ties with pharmaceutical companies that manufacture it or similar drugs, a Mayo Clinic study has found.
The study, which appeared in the March 18 online issue of the British Medical Journal, also found that the disclosure rates for financial conflicts of interest were “unexpectedly low.”
“One-fourth of the folks who were having an opinion on this debate were not disclosing that they had a financial relationship,” said Victor Montori, MD, a Mayo Clinic endocrinologist and one of the authors of the study, in a telephone interview last week.
“This debate” — about whether or not rosiglitazone is safe — has been a heated one, which is not surprising given the huge amounts of money at stake. Rosiglitazone (sold as Avandia by GlaxoSmithKline) was once one of the most heavily marketed and biggest-selling drugs in the world — until, that is, a 2007 review linked it to a significant increased risk of heart attacks. Since then, sales have plummeted, from $3 billion in 2006 to $1.2 billion in 2009, according to Reuters.
As reported earlier this year in the New York Times, an internal battle is now raging within the Food and Drug Administration about whether rosiglitazone should be withdrawn from the market. A confidential FDA report obtained by the Times said that hundreds of cases of heart attacks and heart failures could be averted each month if diabetes patients were switched to other medications.
Widely conflicting views
Letters, commentaries, systematic reviews and meta-analyses about rosiglitazone flooded peer-reviewed journals following the publication of the 2007 review. It was that deluge of papers that triggered the Mayo Clinic study, said Montori.
He and his research group wanted to know if the often diametrically opposed views expressed in those papers — and in other journal articles published before the review — were connected in any way to financial ties between the authors and the pharmaceutical industry.
Numerous other studies have found an association between researchers’ pro-industry study conclusions about various drugs and medical devices and financial conflicts of interest.
So, said Montori, he wasn’t all that surprised that his team, after carefully assessing possible conflicts of interest among the authors of more than 200 scientific papers on the safety of rosiglitazone and similar drugs, “found a significant association between financial relationships and the positions the people held in the controversy.”
A “wimpy” conclusion?
Despite that finding — that more than 90 percent of the authors of positive papers about rosiglitazone had financial ties to the pharmaceutical industry — Montori and his colleagues say their study doesn’t prove a “causal link between the position taken on the cardiac risk of rosiglitazone in patients with diabetes and the authors’ financial conflicts of interest.” (That conclusion was called “wimpy” by Jerome Kassirer, MD, former editor of the New England Journal of Medicine and a outspoken critic of the influence of drug companies on researchers and physicians. “What else could that association be related to?” he asked a Canadian reporter.)
“I’m not making a statement about whether those relationships are appropriate or not,” Montori told me. But, he added, the argument made by some that the push for more industry-physician disclosure has gone too far is misguided.
“I would say our findings highlight the fact that whatever is considered too much right now is actually insufficient to guarantee the public that they are getting the transparency they need,” he said.