CHICAGO, May 21: Avandia, GlaxoSmithKline's widely used drug for treating type 2 diabetes, raises the risk of heart death by 64 per cent and the risk of heart attack by 43 per cent, US researchers said on Monday.
The news about Avandia, a $3 billion a year drug also known as rosiglitazone, triggered a free fall in GSK's shares, which closed off more than five per cent on the London Stock Exchange.The slide continued on the New York Stock Exchange, with shares falling more than eight per cent.
Glaxo said it strongly disagreed with the conclusions of the report, which was based on an analysis of other studies.
“Unfortunately, rosiglitazone appears to increase, rather than decrease, the most serious complication of diabetes, heart disease,” Dr. Steven Nissen, chairman of cardiovascular Medicine at the Cleveland Clinic, said in a statement.
Writing in the New England Journal of Medicine, Nissen and colleagues said they analysed 42 clinical trials involving close to 28,000 patients and said more than 65 percent of the deaths among diabetic patients in the trials of the drug could be attributed to heart disease.
“Unless this can be refuted, which I rather doubt, then this is going to seriously damage one of the cornerstones of Glaxo going forward,” said Paul Diggle, an industry analyst at Nomura Code Securities in London.
But Glaxo disagreed. “GSK stands firmly behind the safety of Avandia when used appropriately, and we believe its significant benefits continue to outweigh any treatment risks,” the company said in a statement.
CALL FOR FDA ACTION: Drs. Bruce Psaty of the University of Washington and Curt Furberg of Wake Forest University, in an accompanying commentary, said the case shows that stronger drug-safety legislation is needed.
“Unless new data provide a different picture of the risk-benefit profile, regulatory action by the Food and Drug Administration is now warranted,” they wrote.
The report by one of the leading U.S. cardiologists caught the eye of lawmakers, heaping new pressure on the FDA to beef up surveillance of drugs once they reach the market. One congressional committee scheduled a hearing on the drug's safety and another questioned why diabetics weren't warned earlier.
The FDA said it had not confirmed the study but said it was continuing to evaluate data and urged diabetics with heart risks to consult their doctors.
The agency said other data provide contradictory evidence about the risks of Avandia, for which some 60 million prescriptions have been written.
Nissen said the study was limited because it did not include access to original data, which would have shown how long it took for patients to have a heart-related problem.
About 21 million people in the United States have diabetes, with 95 percent having type 2 diabetes, which is on the rise in the United States. Diabetes raises the risk of heart disease, kidney failure and other serious complications.
Avandia and Actos, a drug made by Japan's Takeda Pharmaceutical Co. Ltd., are part of a class of drugs known as thiazolidinediones or glitazones.
The first drug in the class, Rezulin, was pulled from the market in March 2000 after about 63 people who took it died from acute liver failure.
Another study in 2003 suggested that Avandia might cause heart failure, and Glaxo warned doctors in February that Avandia increased the risk of bone fractures.
Avandia competes with Merck & Co. Inc.'s Januvia, the first in a new class of diabetes drugs. Merck's shares rose $1 or nearly two per cent on Monday.
