The U.S. Senate's Finance Committee has asked to interview the top health official at the Bill & Melinda Gates Foundation as it investigates whether he and other people he worked with at SmithKline Beecham tried to stifle criticism about Avandia, a popular diabetes drug.
Sen. Chuck Grassley, the ranking Republican on the finance committee, is conducting a wider investigation about whether several pharmaceutical companies have tried to suppress criticism of their drugs in recent years and how the Food and Drug Administration has responded.
Grassley and Sen. Max Baucus, the committee's senior Democrat, sent a letter to Tadataka "Tachi" Yamada, who is now president of the Gates Foundation's global health program, on Friday asking him to discuss SmithKline's actions with staff lawyers.
Yamada was head of research for SmithKline when it began selling Avandia in 1999. The company became GlaxoSmithKline when Glaxo Wellcome and SmithKline Beecham merged in 2000.
Earlier this week, the committee released a staff report calling the company's actions "intimidation." Internal company documents, the report said, "reveal what appears to be an orchestrated plan to stifle the opinion" of John Buse, a University of North Carolina doctor who said at a 1999 medical conference that Avandia could cause heart attacks.
‘Trying to correct inaccuracies’
GlaxoSmithKline has objected to the Senate committee's report, saying it did not try to silence Buse but was only "trying to correct inaccuracies about data on Avandia" voiced by Buse in the medical seminar.
In an e-mailed statement, GlaxoSmithKline spokeswoman Nancy Pekarek said the company apologized to Buse eight years ago for the way it handled interactions with him.
"GlaxoSmithKline understands that there is a fundamental difference between engaging in scientific debate to ensure the accuracy of public statements, and trying to inappropriately influence or silence a critic," Pekarek said. "The company does not support or condone efforts to silence critics."
In a written statement, Yamada said his contact with Buse was prompted by those same concerns. Yamada said he made a phone call to Buse's boss, who was "an old friend, so I felt comfortable calling him to probe informally about his opinion of Dr. Buse."
Yamada said through his personal spokesman, David Marriott, that he would be happy to talk with the committee staff.
The committee report cited several internal e-mails in which Yamada and company executives discussed how to suppress Buse's alarms.
FDA warns of heart-attack risk
Last May, the New England Journal of Medicine reported that Avandia could increase the risk of heart attack by 43 percent. Last week, the FDA added its highest-level "black box" warning about heart-attack risks to Avandia's label.
According to the committee report, FDA scientists estimated that "Avandia caused approximately 83,000 excess heart attacks since coming on the market."
In testimony to the House earlier this year, Buse said he was characterized as a "liar" and threatened with a lawsuit if SmithKline's stock dropped because of his statements about the drug's safety.
Buse, who was named president of the American Diabetes Association in September, has toned down his criticism since then. In an interview last month with the journal Nature, Buse said, "I don't think Dr. Yamada is the bad guy in this story."
Yamada was recently named to an FDA commission set up to enhance drug safety.
His involvement in a Senate investigation could pose a dilemma for the foundation, which is counting on cooperation from large pharmaceutical companies like GlaxoSmithKline to develop a vaccine for malaria.
When approached by a Seattle Times reporter at a recent Gates Foundation-sponsored malaria forum in Seattle, Yamada declined to discuss the Senate probe.
Asked whether it would affect his work at the Gates Foundation, Yamada replied, "I hope not.
"I'm not with that company anymore. It's something for GSK," Yamada said. "I have a job to do and I'm really committed to it."