Study used to support diabetes drug Avandia is denounced in FDA review
WASHINGTON — A federal drug official dealt a severe blow Friday to the popular diabetes drug Avandia, issuing a scathing review of a major clinical trial that its manufacturer has been using to argue that the drug was safe.
The reviewer, Dr. Thomas Marciniak of the Food and Drug Administration, found a dozen instances in which patients taking Avandia appeared to have serious heart problems that were not counted in the study’s tally of adverse events.
Such repeated mistakes “should not be found even as single occurrences” and “suggest serious flaws with trial conduct,” Marciniak wrote.
The detailed report could prove crucial next week, when a panel of experts meets to consider whether to recommend to the FDA that the manufacturer, GlaxoSmithKline, withdraw Avandia from the market or restrict its sale.
The panel’s decision will have broad consequences for the company, the FDA and perhaps even the entire process by which medical products are approved. The agency rarely does clinical trials on its own, depending on drug companies to conduct them appropriately.
Avandia, which helps patients get better control of their blood sugar levels, has already come under intense criticism. It has been shown to increase the risks of bone fractures and to cause swelling that can lead to heart failure and eye problems. And a number of studies, including some by GlaxoSmithKline, suggest that it could increase the risks of heart at- Dr. Thomas Marciniak of the FDA said he found omissions in a drug trial report that suggest Avandia raises the risk of stroke and heart problems. tack, stroke and death.
GlaxoSmithKline has relied heavily on the major clinical trial, nicknamed Record, to demonstrate that those risks are exaggerated.
Marciniak’s review of the Record study calls that assertion into question. He found one case in which a seizure patient was hospitalized for bleeding in the brain, but all mention of the episode was deleted from records. Another patient was hospitalized for 67 days after a severe stroke, but the study record showed no sign of a cardiovascular problem.
Another patient died after being hospitalized for a serious heart problem, but the death was listed as arising from an unknown cause and not as being heart-related.
Correctly interpreted, he concluded, the study actually supports critics’ contentions that Avandia may cause heart attacks and strokes.
“One does not have to be a mathematician or to perform calculations,” he wrote, to come to the conclusion that a combined look at all the trials of Avandia would demonstrate that it causes heart attacks.
Mary Anne Rhyne, a spokeswoman for GlaxoSmithKline, said, “The Record study was conducted according to good clinical practices, and the data are reliable.”
Marciniak’s review is part of a reassessment of Avandia’s safety by FDA medical officers to educate the panel meeting Tuesday and Wednesday.
Debate about Avandia’s safety and how to handle reports of its dangers has split the food and drug agency and led to fierce recriminations, staff departures and questions from Congress.
It was the FDA’s delay in issuing stronger warnings about Avandia that led Congress in 2007 to give the agency greater powers over drug makers.
Within the FDA, some officials insist that the evidence is mixed and others say it is strong enough to merit the drug’s withdrawal. An advisory meeting in 2007 concluded that Avandia did increase heart attack risks but that it should stay on the market.
Although endocrinologists have advised against its use, Avandia remains popular — with nearly 2 million prescriptions last year. If the drug were to be withdrawn, GlaxoSmithKline — already facing lawsuits claiming Avandia caused injuries — would likely see its liability soar.