New Avandia study sheds little light on heart risk

WASHINGTON (Reuters) - An early analysis from an ongoing study of GlaxoSmithKline Plc's Avandia was unable to show whether there was any increase in heart attacks among patients, but several experts said the evidence still suggested the popular diabetes drug raised the risk of heart attack.

Glaxo and three independent heart experts had sharply different views on what the results of the study meant.

The interim analysis of the study, funded by the drugmaker and published in the New England Journal of Medicine on Tuesday, was hastily published after another report last month suggested Avandia raised the risk considerably.

The study by Dr. Steven Nissen of the Cleveland Clinic in Ohio created a stir, and a U.S. House of Representatives committee will hold a hearing on Wednesday about whether the U.S. Food and Drug Administration can properly police such drugs.

Dr. Philip Home of Britain's Newcastle University and a team from around the world looked at the ongoing study of 4,400 patients to see if they could find any evidence that patients taking Avandia, known generically as rosiglitazone, were more likely to have a heart attack.

Their conclusion: they could not tell. "Because the mean follow-up was only 3.75 years, our interim analysis had limited statistical power to detect treatment differences," Home's team wrote.

"Patients and physicians should find these data reassuring," Moncef Slaoui, Glaxo's research and development chairman, said in a statement. Millions of diabetes patients take Avandia.

But Dr. Bruce Psaty of the University of Washington in Seattle and Dr. Curt Furberg of Wake Forest University said all the trials studied so far, pooled with this one, suggest a 33 percent higher risk of heart attack.

"Rosiglitazone ... appears to be associated with an increase rather than a decrease in the risk of myocardial infarction (heart attack)," they wrote in a commentary.

HARD TO INTERPRET

Dr. David Nathan, a diabetes expert at Massachusetts General Hospital and Harvard Medical School, said the data were hard to interpret.

"The interim results of the Record trial do not provide any assurance of the safety of treatment with rosiglitazone," Nathan wrote in a second commentary.

Glaxo accused the experts of bias. "We believe the NEJM editorials are selective in their use of data to support a biased view, and therefore do a disservice to patients, physicians, science and public health," the company said in a statement.

Nissen's study was not conclusive and most experts agree the continuing trial, called Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of glycemia in Diabetes, or Record for short, should provide a more authoritative answer.

Record is only halfway finished and was not specifically designed to detect an increased rate of heart attack.

"There were no statistically significant differences between the rosiglitazone group and the control group regarding (heart attack) and death from cardiovascular cause or any cause," Home's team wrote.

"The data were insufficient to determine whether the drug was associated with an increase in the risk of (heart attack)," they added. A final analysis is not expected until the trial concludes in 2009.

Psaty and Furberg also noted that Avandia is associated with a risk of weight gain and fractures, and raises low density lipoprotein or "bad" cholesterol levels. They said patients should consult with their doctors about whether to take Avandia.

(With additional reporting by Lisa Richwine in Washington and Ransdell Pierson in New York)