A fiery US House of Representatives committee hearing on GlaxoSmithKline’s diabetes treatment Avandia® (rosiglitazone) has heard that regulators had decided to call for a strengthening of the drug’s label as early as 23 May, two days after a meta-analysis called the treatment’s safety into question.
In a written statement to the hearing, FDA Commissioner Andrew von Eschenbach revealed that the US regulator requested on May 23 “a more prominent warning” for Avandia, as well as for Takeda and Eli Lilly’s Actos® (pioglitazone), because “despite existing warnings, these drugs were being prescribed to patients with significant heart failure”. Takeda confirmed it would add a boxed warning, while GSK says it is discussing the request with the FDA.
The hearing is looking at why such a warning had not been applied to Avandia years before, when fears of the risk of congestive heart failure surfaced first. The FDA was also criticised for waiting until yesterday to go public with its request, two weeks after the New England Journal of Medicine published the meta-analysis authored by Dr Steven Nissen which suggested the drug might significantly increase the risk of heart attacks.
Mr von Eschenbach’s letter explained that all the studies “are inconsistent and conclusions are not clear” on Avandia’s possible contribution to heart attacks, so the FDA “is not at present justified in taking additional regulatory action or recommending that patients stop using it”.
The committee also heard from GSK R&D chairman Dr Moncef Slaoui, who said the company “strongly believes that the overall safety of Avandia is comparable to other available oral anti-diabetes medicines”. The firm also released yet more new data to support this view, this time from a large-scale observational study of 33,000 patients with type 2 diabetes in a real-world setting and published in Pharmacoepidemiology and Drug Safety.
However there was more to come when endocrinologist Dr John Buse, who is soon to take over as president of the American Diabetes Association, claimed he was threatened in 1999 by employees of SmithKline Beecham (which later merged with Glaxo Wellcome to form GSK) after he had raised concerns about Avandia.
Dr Buse said SmithKline officials called him a “liar” and challenged his integrity by saying he was “for sale”, then threatened him with a lawsuit. “The market capitalisation of the company had declined by $4bn and there were people in the company who felt I might be liable for that.”
After that, Dr Buse wrote to Tachi Yamada, then SmithKline’s head of R&D, saying: “Please call off the dogs. I cannot remain civilised much longer under this type of heat.” He then signed a statement, drafted by the firm, which clarified his views on Avandia and agreed to work with SmithKline to study the drug further. A GSK statement said: “We regret if, at any time, Dr Buse felt the conduct of any GSK employee was contrary to the spirit of open, scientific debate regarding his views on Avandia.”