Controversy over diabetes drug Avandia heated up Wednesday as experts pointed to studies linking it to greater heart attack risk, while a GSK study claimed rosiglitazone is safe.
The GlaxoSmithKline study published online Tuesday by the New England Journal of Medicine (NEJM) gave preliminary results of a four-year clinical study of 4,446 patients showing Avandia did not increase the rate of heart attacks or death.
Among the sub-group of patients who took Avandia, 29 died from heart attacks, against 35 who died from a control group taking two other drugs for adult-onset, type 2 diabetes, GSK said in the study.
In a study that analyzed 42 clinical trials published May 21 by NJEM, eminent cardiologist Steven Nissen of the Cleveland Clinic, in Ohio, said Avandia increased the risk of heart attacks by 43 percent.
The initial results of the GSK-funded research, the Record Study Group, which challenges Nissan's conclusions, failed to convince several well known US medical experts, said an NEJM editorial.
"The interim results of the Record trial do not provide assurance of the safety of treatment with rosiglitazone (Avandia).
If anything, it shows the opposite," said Massachusetts General Hospital diabetes expert David Nathan.
In a separate editorial in Tuesday's NEJM, Bruce Psaty of the University of Washington in Seattle and Curt Furberg of Wake Forest University, North Carolina, re-evaluated the heart risks in GSK's Record study using Nissen's methodology.
They found Avandia raised the risk of heart attack by 33 percent.
"In my mind, its not small," wrote Furberg, who said that extrapolating the results to the millions of diabetes patients taking Avandia meant thousands more people would have heart attacks.
The Committee on Oversight and Government Reform of the House of Representatives on Wednesday held a hearing on Avandia, focusing on the US Food and Drug Administration's role in its approval in 1999.
The FDA has come under fire for approving Merck's anti-inflammation drug Vioxx, which was taken off the shelves in 2004 after it was linked to increased heart attacks and death.
"By examining Avandia ...
we can learn a lot about the drug approval and the post-market surveillance process," Democratic Representative Henry Waxman, of California, told the hearing.
"Avandia is a case study of the need for reform of the nation's drug safety laws," he added.
The House panel was keen on hearing from Rosemary Johann-Liang, from the FDA Office of Drug Safety, who in an NEJM interview said she had approved in March 2006 a recommendation from FDA inspectors to toughen a warning label on Avandia to stress its increased risk for heart attacks.
Johann-Liang said she was pressured to go back on her decision after FDA officials were contacted by GSK.
FDA Commissioner Andrew von Eschenbach, Nissan, and a GSK representative are expected to testify at the House hearing on Wednesday.