U.S. Food and Drug Administration officials are pushing for a "black box" warning of the risk of heart attack on GlaxoSmithKline Plc's diabetes drug Avandia, the Wall Street Journal reported on Wednesday, citing unnamed sources.
The drug already carries one FDA black box warning for another condition, heart failure — when a weakened heart cannot pump blood effectively. A warning for the risk of heart attack would be more serious.
Another black box label warning — the strongest given by the FDA — would be a further blow to the once-top-selling diabetes drug, which came under pressure last May when an analysis linked Avandia to a 43 percent higher risk of heart attack.
Sales have plummeted since, to the benefit of rival drug Actos, sold by Takeda Pharmaceutical Co (4502.T: Quote, NEWS , Research).
Glaxo Chief Executive J.P. Garnier said the London-based company has not heard anything from the FDA about further warnings. "In terms of further changes to the label, we will have to wait and see," Garnier said during a conference call about the company's latest quarterly results.
A spokesman for the FDA said the agency could not comment.
Shares of Glaxo fell about 2 percent after the company reported third-quarter sales below analysts' average estimate and on concern about the growth in another Glaxo product, Advair.
Industry analysts said such a strong warning on Avandia would not be surprising, given the sentiment at an FDA advisory panel meeting in July.
"This issue has been discussed in detail at the last FDA panel, so it's sort of expected," Shaojing Tong, an analyst at Mehta Partners, said. Avandia's market share could fall even more, he said.
The European Medicines Agency last week recommended a tighter label for Avandia but said the benefits outweighed risks for the drug and for a similar one, Actos.
Avandia posted global sales of $3.24 billion last year, making it the company's second-biggest seller. (Reporting by Kim Dixon in Washington, with additional reporting by Dane Hamilton in New York and Michael Kahn in London).