A US Senate committee has asked to interview the Bill & Melinda Gates Foundation’s top health official as part of an ongoing investigation into whether he and others at his former company attempted to intimidate a scientist who revealed dangers about Glaxo’s Avandia diabetes pill, The Seattle Times reports.

The Senate Finance Committee is reviewing allegations that Tadataka “Tachi” Yamada and other former SmithKline Beecham execs tried to stifle criticism from John Buse, a University of North Carolina diabetes expert, who told a medical conference that Avandia could cause potential fatal side effects, including heart attacks. Yamada, who is now president of the Gates Foundation’s global health program, was head of research for SmithKline - which later merged with Glaxo - when Avandia hit the market in 1999.

Chuck Grassley, the Senator from Iowa and the committee’s ranking Republican, is spearheading a broader investigation into whether several major drugmakers tried to suppress negative information about different meds in recent years, and whether FDA officials may have helped them. Grassley and Max Baucus, a Democrat from Montana and the committee chairman, sent a letter to Yamada on Friday asking him to discuss actions with staff lawyers, the Times writes.

The day before the letter was sent, the Finance Committee released a staff report (look here) calling the company’s actions “intimidation” and internal documents “reveal what appears to be an orchestrated plan to stifle the opinion” of Buse. Glaxo disputes the report, saying it did not try to silence Buse but was only “trying to correct inaccuracies about data on Avandia” made by Buse in a medical seminar.

In a written statement to The Seattle Times, Yamada claims his contact with Buse was prompted by those same concerns and that 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 adds through his personal spokesman, Dave 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 execs discussed how to suppress Buse’s alarms. In one, Yamada suggested that the company sue Buse or start a campaign to trumpet the benefits of Avandia. “One (course of action) is to sue (Buse) for knowingly defaming our product,” Yamada wrote in an e-mail. “The other is to launch a well-planned offensive on behalf of Avandia so that listeners begin to understand…there are two sides to this story.” Yamada recommended the latter action.

Meanwhile, Buse was proven correct. Last May, The New England Journal of Medicine reported a controversial meta-analysis that Avandia could increase the risk of heart attacks by 43 percent. And last week, the FDA added a new Black Box warning about heart-attack risks onto Avandia’s label; the first one warns of heart failure.

The Senate committee report said that had SmithKline considered the risks first raised by Buse more seriously, “instead of trying to smother an independent medical opinion, some of these heart attacks may have been avoided.” According to the committee report, FDA medical reviewers 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 statements he made about Avandia’s possible dangers. But Buse, who was named president of the American Diabetes Association in September, has been less vocal recently. 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 has just been named as one of 14 board members to the FDA’s new Reagan-Udall Foundation, which was created to foster drug research as part of a bill on FDA changes that passed Congress in September. Yamada’s involvement in the Senate investigation poses a dilemma for the Gates Foundation. The foundation is counting on cooperation with large drugmakers like Glaxo to realize its most ambitious goals, including developing the world’s first vaccine for malaria.

Yamada, who joined the foundation directly from Glaxo in 2006, is leading those efforts. When approached by a reporter at a recent Gates-sponsored malaria forum in Seattle, Yamada declined to discuss Grassley’s 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 (Glaxo),” Yamada said. “I have a job to do and I’m really committed to it.”

Yamada is the second Gates Foundation health chief whose past work has been questioned. Richard Klausner, the foundation’s previous director of global health, resigned after it was reported that he had been investigated by the Government Accountability Office for possible conflict-of-interest violations during his tenure at the National Cancer Institute. Klausner denied any wrongdoing. He is now a managing partner at a venture-capital firm focused on biotechnology.

Drug-safety expert Bruce Psaty, a professor of medicine at the University of Washington, says he isn’t surprised by the committee staff’s worries of a troubling pattern of behavior by drugmakers toward their critics. When a blockbuster drug is involved, marketing often winds up superseding science, he says. He called it the “It’s your child” syndrome. “People don’t like it when their children are criticized,” he says. “People are not going to want to hear that something is wrong with the drug.”

Source of breaking news: The Seattle Times