FDA panel divided over new diet drug
March 13, 1998
Web posted at: 11:44 p.m. EST (0444 GMT)
GAITHERSBURG, Maryland (CNN) -- A federal advisory panel could not reach a decision Friday on whether the Food and Drug Administration should approve the use of Xenical, a new anti-obesity drug, because of concerns of a possible link between the drug and breast cancer.
The 5-to-5 vote by the FDA advisory panel means that it will be up to the FDA to make a final decision, which is likely to come in May.
Xenical works by preventing the body from absorbing about one-third of the fat in the food a person eats. In a one-year trial of the drug, the average patient lost 10 percent of his or her body weight.
The drug does have uncomfortable side effects. The more fat people eat while taking Xenical, the more likely they are to suffer cramping and diarrhea.
Still, doctors think Xenical, while not for the casual dieter, could be a short-term crutch for the truly obese so that they can change bad eating habits and start an exercise program.
Concerns about breast cancer
But the advisory panel had questions about the drug's possible link to breast cancer, not Xenical's side effects.
In a study of 4,000 women conducted by the drug's manufacturer, Hoffman-La Roche, nine women taking the drug developed breast cancer, compared to one woman on a similar group taking a placebo.
Despite that finding, the same FDA advisory panel recommended the drug's approval in May 1997.
But Roche held up the application to study the breast cancer issue further. In the interim, it found two new cases in Xenical patients and two more in the placebo group.
Roche officials argue that because Xenical only works in the digestive system, there is no strong biological explanation of how it could cause cancer. Some panel members said while they too were unsure about a connection, they didn't want to take a chance on approving the drug.
"I do not know what accounts for the finding in the trial, but I know I can't discount it," said panel member Bruce Stadel.
"I'm not certain that it causes breast cancer, but I'm not certain it doesn't have something to do with it as well," said panelist Robert Siegel of George Washington University.
Medical Correspondent Linda Ciampa and Reuters contributed to this report.