Advisory Panel Votes 8 to 8 on Whether to Keep Weight Loss Drug on the U.S. Market
By Todd Zwillich
WebMD Health News
Reviewed by Laura J. Martin, MD
The decision likely imperils the drug's future. The FDA is currently deciding whether the modest weight loss the drug delivers to most patients is worth an increased risk of cardiovascular events like stroke or heart attack.
Meridia, also known as sibutramine, was first approved in the U.S. in 1997, but lately has been facing controversy. A large study released last November shows that people who took the drug had an 11% risk of cardiovascular events, while those who took a placebo had a 10% risk.
The study, called the SCOUT trial, prompted regulators to order the drug off the market in Europe. Calls quickly mounted for the drug to be banned in the U.S.
Meridia has been shown to reduce weight in many patients. The average patient who responds to the drug loses 4% more body weight below what they might lose with a placebo, an amount considered a modest benefit. About one-fifth of patients lose more. But the drug also causes increases in heart rate and blood pressure, both of which pose a danger to patients with cardiovascular disease.
The drug is already not supposed to be used in patients with known cardiovascular disease. But experts said they were troubled that many patients with undiagnosed disease could be at greater risk if they use the drug to lose weight.
That essentially caused a conflict: the cardiovascular benefits of modest weight loss vs. a slightly increased risk of heart attack or stroke caused by the body's metabolism of the drug.
"The question has always been, of these competing forces, which ones will win out in terms of cardiovascular risk?" says Eric Colman, MD, deputy director of the FDA's Office of Metabolism and Endocrinology Products.
The FDA's own monitoring linked 14 deaths to the use of Meridia. Patients who died were 43 years old, on average, and 71% were women.
Ultimately, the 16-member advisory committee was divided on the tradeoff. Half urged the FDA to ban Meridia outright, while half said the agency should keep it on the market but with new warnings and significant restrictions on who can prescribe it.
"It's one of the few ways that you can lose weight and not get any of the benefits from doing so. That concerns me," says Lamont G. Weide, MD, PhD, a professor of medicine and diabetes expert at the University of Missouri, Kansas City and a member of the panel.
The Public Citizen Health Research Group, which first petitioned FDA to ban Meridia in 2002, says the drug poses a "deadly tradeoff" between modest weight loss and the danger of heart attack and stroke.
Others say Meridia can be made safe by closely monitoring things like patients' pulses and blood pressure readings. "I think the risk is manageable under a physician's care," says Melanie Coffin, the panel's consumer representative.
Abbott, which manufactures Meridia, had pledged step up warnings and educational efforts for doctors and patients if the drug is allowed to stay on the market.
"The vote highlights the complexity of this scientific debate," Eugene Sun, MD, the company's vice president of global pharmaceutical development, said in a statement. "We continue to believe that there are appropriate and identifiable patients that derive benefit from sibutramine."
Meridia's popularity has plummeted in recent years, particularly since the release of the Scout trial's data in November. Only an estimated 280,000 prescriptions were filled last year in the U.S., according to the tracking firm IMS Health.
Some experts worried that the list of effective treatments available to patients had grown thin.
Banning Meridia "just takes one more option off the table," Coffin says.
Sanjav Kaul, MD, a panel member and cardiologist at Cedars-Sinai Medical Center in Los Angeles, suggests that Meridia had turned out to be a disappointment to patients hoping to use it to safely lose weight.
"It was touted to be a magic bullet, but in some cases it's more bullet than magic," he says.
Colman says the FDA now has to decide if the clear benefits of even modest weight loss to most patients is worth a rise in cardiovascular risk in some of them. The FDA will also likely consider what vital signs doctors should monitor, and how often they should monitor them, to minimize the drug's risks.
The advisory panel's split vote "certainly doesn't make it easier for us," Colman told reporters.
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