Six months after American Home Products Corp. recalled Redux over safety concerns, the company is releasing new data suggesting the diet pill is far less dangerous than previously thought.
Last September, the U.S. Food and Drug Administration shocked doctors and diet-drug patients by reporting that about 30% of people using Redux, or a combination of diet pills called "fen-phen," suffered damage to their heart valves -- a rate significantly higher than the 2% to 6% of heart-valve problems found in the general population. American Home quickly pulled Redux off the market, upsetting many overweight people successfully using the drug. The recall led to numerous lawsuits against American Home, caused many worried users to have their hearts examined and fueled debates questioning the FDA data as well as the medical community's aggressive use of the diet pills.
The new study of 1,072 people is the first of several sponsored by American Home in an effort to exonerate its pills, which include both Redux and a chemical cousin called Pondimin that was also recalled. Performed by cardiologists at Georgetown University in Washington, D.C., the new research found 6.5% to 7.3% of 676 patients who had taken one of two forms of Redux had heart-valve problems, compared with 4.5% of patients who had taken a dummy pill. The study only looked at short-term use of the drug.
The researchers, who delivered the new data late Tuesday at a meeting of the American College of Cardiology in Atlanta, said the difference between Redux users and the control group is "not statistically significant." Neil Weissman, a Georgetown cardiologist who led the study, described the difference as "small," noting that while the results are "reassuring" to Redux users, further studies will be needed to assess the danger to people who took Redux longer or with other diet medicines.
Some diet-pill doctors urged caution interpreting the new results. "I don't think any single study is going to be definitive," said Richard Atkinson, a researcher at the University of Wisconsin, who said a third of his diet-drug patients developed heart-valve leaks. "We don't know what's going on here. It's very mysterious," he said.
American Home officials said that even if its studies exonerate Redux, it would never seek to market the drug again because of the liability situation. But the substantial difference between the FDA survey and the new Georgetown results should provide a boost to American Home in fighting its lawsuits.
Wall Street seemed to expect the good news. American Home's shares surged on the New York Stock Exchange on Monday and closed Tuesday in composite trading at $95.375, up $3.625. In addition, shares of Interneuron Pharmaceuticals Inc., a small Lexington, Mass., company that licensed the drug to American Home, jumped $2.0625, or 25%, to $10.4375 in composite trading on the Nasdaq Stock Market.
American Home's legal opponents were unimpressed by the new study. "This isn't science, it's American Home buying a legal defense," said John Cummings III, a lawyer at Cummings, Cummings, Dudenhefer & Martin who is helping to coordinate diet-drug lawsuits. "All of these studies sponsored by American Home are suspect."
The study didn't include any patients on fen-phen, the popular diet-drug combo used by millions of Americans in recent years. Fenfluramine, a chemical cousin of Redux, was also marketed by American Home as Pondimin, while phentermine is marketed by several companies. Only Redux and Pondimin were recalled. The FDA never approved the use of fenfluramine with phentermine.
Moreover, patients in the new study were on Redux about 2.5 months, far shorter than the six to 12 months of use among many patients in last year's FDA survey.
"That's a very short period of time considering that the drug was marketed for longer-term use" of up to a year, said Michael Myers, an obesity specialist in Los Alamitos, Calif., who has opposed use of Redux. "I hope the results are true, but you can't form a conclusion from such limited data."
The FDA, which reviewed the study, said the new data are good news for patients who took Redux for three months or less. But the agency pointed out that the results don't apply to the large numbers of people who took it longer. American Home said the new study is valid because its market data suggest that 86% of Redux users stayed on the drug for 90 days or less.
Mehmood Khan, chief of endocrinology at Hennepin County Medical Center in Minneapolis, said he still stands by his preliminary findings, released last fall, that about 25% of patients taking appetite-suppressant drugs developed valve leaks, compared with only 1% in a placebo group.
Nevertheless, some obese patients feel the medications should be back on the market. Randy Voss, a 46-year-old livestock farmer from LaValle, Wis., said he took fen-phen for a year without side effects, allowing him for the first time in his adult life to maintain a normal weight and control his severe diabetes problem. He has gained 25 pounds since the drugs were recalled.
Morton Maxwell, a Los Angeles diet doctor, said the drugs should be marketed again for some patients because even if they cause some valve problems, their benefit to severely overweight people outweighs their risks.
The American Home study was actually begun before the recall to determine the weight-loss effects of a new long-acting form of Redux. Patients either received the long-acting Redux, normal Redux or a dummy pill. The study was stopped when the drug was recalled. But following the recall, patients had echocardiograms, or heart ultrasounds, performed on them to see if they had any heart problems. The study was blinded, meaning that neither the patients nor the doctors performing or reading the echocardiograms knew who had received Redux and who had received a dummy pill.
The potential side effects of the diet drugs surfaced last summer when researchers from the Mayo Clinic published results in the New England Journal of Medicine showing that 24 previously healthy woman developed rare heart-valve lesions within a year after they started taking fen-phen; five required surgery. American Home at the time said the results were inconclusive and only applied to Pondimin, not Redux. Nevertheless, sales of both drugs began to drop precipitously.
Just weeks before the recall, American Home officials still argued the diet drugs were as safe as other prescription medications on the market. But in early September, the FDA informed American Home that a survey of five clinicians had found that nearly one-third of 291 fen-phen and Redux patients had heart problems, and asked it to withdraw the drugs. Faced with the new evidence, American Home recalled the drugs on Sept. 15, at a cost of over $100 million.
The original FDA findings, while alarming, weren't considered definitive because they didn't result from a controlled study but from a survey in which several doctors specifically looked for heart problems among diet-drug users. The new study, despite its limitations, has the benefit of being blinded and controlled, suggesting it may be more reliable.
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