A heated three-year safety debate about a GlaxoSmithKline Plc diabetes pill reaches a climax this week as opponents and backers face off at a U.S. meeting that will help decide the drug's fate.
A panel of scientific experts meets later Tuesday and again Wednesday to consider if Avandia is too dangerous to stay on the market. The advisers to the U.S. Food and Drug Administration must sort through sharply conflicting data on whether the medicine causes heart attacks.
The recommendations of the panel, with 33 voting members, are expected to weigh heavily on the FDA in making its final decision in the coming months.
British-based Glaxo could face a new wave of lawsuits if the drug comes off the market.
The pill was once Glaxo's second-biggest drug but its sales have plunged since safety fears erupted three years ago. Revenues totaled 771 million pounds ($1.16 billion) in 2009, equivalent to 2.7 percent of Glaxo's group sales.
Added pressure is coming from the European Medicines Agency, which has launched a new review into Avandia's risks and benefits.
For the FDA, the case is seen as a test of how the agency will handle major controversies under Democratic President Barack Obama. Officials are facing heavy pressure from consumer groups and some lawmakers who say the FDA fumbled decisions in past administrations and failed to protect the public.
Some staff see the Glaxo drug as more dangerous to the heart than Takeda Pharmaceutical Co's rival diabetes pill, Actos, with no unique benefits. Others remain unconvinced Avandia raises heart-attack risk. The current warning on the drug, added in 2007, says the data is "inconclusive."
Glaxo has vigorously defended the medicine, based in part on a study called Record that found no higher rates of heart-related hospitalizations or deaths.
Company presenters will lead off Tuesday's session, scheduled to begin at 7:45 a.m. EDT (1145 GMT), followed by a parade of FDA staff and outside experts that will continue on Wednesday morning.
On Wednesday afternoon, the panel of cardiologists, endocrinologist and other experts will be asked to choose one of five options, ranging from keeping the drug on the market without a heart-attack warning to recommending a withdrawal. Restricting use or beefing up warnings are other choices.
"There is a question in some of the scientific community about whether there's a signal here," Dr. Janet Woodcock, head of the FDA's drug division, told reporters at a briefing ahead of the advisory panel meeting.
Many drugs faced scrutiny in the past for risks that later proved untrue, Woodcock said. She pointed to calcium channel blockers, widely used heart drugs that were tied to heart disease, cancer and other problems in the 1990s. Later studies concluded those risks did not exist, she said.