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Health official speaks out about row over drug critic

Fresh light is shed on dispute over diabetes pill.

The former drug-company official who heads global health at the Bill and Melinda Gates Foundation has broken his silence over accusations of acting inappropriately eight years ago, when a physician raised questions about the safety of one of the company's drugs.

The drug, Avandia (rosiglitazone), has come under scrutiny this year after two meta-analyses1, 2 concluded that it significantly increases the risks of heart attack. So far, both US and European regulators have kept Avandia on the market, although US officials are considering regulatory action.

Fresh questions arose last month after Senator Charles Grassley (Republican, Iowa) made public a 1999 e-mail exchange between Gates official Tachi Yamada — who was then chief of research and development at Avandia's maker, SmithKline Beecham — and William Claypool, the company's director of worldwide clinical development.

Avandia had just won regulatory approval. But speaking at a scientific meeting 5 days before the exchange, John Buse of the University of North Carolina noted that there were about 50% more cardiovascular deaths in subjects who took Avandia than in those on other diabetes drugs, although the difference was not statistically significant. Buse then mis-stated the cardiovascular death rate of trial subjects taking a placebo drug, saying it was lower than in those on Avandia. He later corrected this in a statement that the company showed to investors.

Experts have quarrelled over Avandia's safety record. Credit: J. SULLIVAN/GETTY

But Claypool wrote to Yamada that Buse had "repeatedly and intentionally misrepresented Avandia data from the speaker's dais". He suggested that Buse be warned to stop, "with the punishment being that we will complain up his academic line". He added that a lawsuit could be "reserved for a later approach".

Yamada replied: "I think that there are two courses of action. One is to sue him for knowingly defaming our product even after we have set him straight as to the facts. The other is to launch a well-planned offensive on behalf of Avandia." Yamada recommended the latter.

In an interview with Nature last week, Yamada said that after receiving Claypool's e-mail he called Buse's boss "to be certain that he was a legitimate academic". He said that he was reassured to learn that Buse was "a qualified scientist making the best of the data that he had". A careful reading of the e-mails released by Grassley, Yamada added, shows that "I did not initiate any discussion of a lawsuit [against Buse]". He added: "Nor did I ever discuss a lawsuit with anybody else … I wouldn't want the media to think it's some diabolical plot hatched by me against Dr Buse, because nothing could be further from the truth."

"I don't think that Dr Yamada is the bad guy in this story," Buse says. "He did his job and he did it in a fairly sensitive way." He adds that he didn't have a problem, then or now, with Yamada calling his chairman to check his credentials. "That wasn't the disturbing bit. The most disturbing part was the veiled threat of a lawsuit."

Buse said that the threat came from one of many other company officials who deluged him with phone calls — prompting him to write to Yamada, asking him to "call off the dogs".


  1. 1

    Nissen, S. E. & Wolski, K. N. Engl. J. Med. 356, 2457–2471 (2007).

  2. 2

    Singh, S. et al. 298, 1189–1195 (2007).

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Congressional Record transcript of Claypool-Yamada email exchange 12 September 2007

Tachi Yamada biography

John Buse

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Wadman, M. Health official speaks out about row over drug critic. Nature 449, 952–953 (2007).

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