Bayer AG's heart surgery drug Trasylol appears to increase the risk of kidney failure and the risk of death, U.S. regulators said in documents released on Monday.
A U.S. Food and Drug Administration advisory panel will once again review the safety of Trasylol on Wednesday, following emergence of troubling data just days after another FDA advisory panel met last year over the drug's safety.
That first advisory panel found the drug, used to stem bleeding and the need for blood transfusions during surgery, was acceptable for some patients undergoing heart surgery.
German drugmaker Bayer says it mistakenly withheld a study of 67,000 hospital records suggesting the drug could increase the risk of death, serious kidney damage, congestive heart failure and stroke.
Drug's risks studied
FDA staff, in briefing documents ahead of Wednesday's advisory panel, said the totality of three recent studies support the risk of renal failure and dysfunction, and noted a "mortality disadvantage detected" in the Bayer study.
A Bayer spokeswoman said the company looks forward to discussing the drug's merits at the advisory panel meeting.
The drug, approved in 1993, is given by injection to prevent blood loss during cardiac bypass surgery. It is the only FDA-approved drug for that use, though doctors often turn to two older generic drugs for the same purpose, experts have said.
Wall Street analysts originally forecast that Trasylol could generate sales of more than $500 million, but those estimates have greatly diminished amid the safety issues and after an FDA label warning was added last year.
"There is still no new clinical data, so the question is whether (Bayer's) observational study is enough of an alarm," said Ira Loss, an analyst at the investor research firm Washington Analysis.
"My assumption is this drug is being put into the dead-end of drug land," he added.
Of that withheld Bayer study, FDA staff said that "use of this study alone would be inappropriate for drawing any firm conclusions" regarding the drug's safety in coronary artery bypass graft surgery patients.
Bayer has said it did not share the findings with the FDA because they were preliminary, though it has suspended two senior staffers over the issue.
The first FDA panel in September 2006 was reviewing data from medical journals that suggested the drug might increase the chance of kidney damage, heart attacks and strokes.
In European trading, Bayer's stock eased 0.44 percent.