Two U.S. Food and Drug Administration (FDA) advisory committees voted on January 23rd to recommend that the regulatory agency approve GlaxoSmithKline's petition to sell a half-dose version of the diet drug Xenical (orlistat) without a prescription.

The FDA advisory committees, following an all-day meeting at which they heard arguments both for and against approving the proposed six-month treatment with an over-the-counter (OTC) version of Xenical which would be marketed as alli, voted 11-to-3 in favor of non-prescription sale of the drug.

If the FDA, which generally follows the nonbinding recommendations of its advisory panels of outside experts, ultimately approves alli, it will be the only FDA-endorsed weight-loss drug available without a prescription. But final FDA approval may still take months.

If approved, Glaxo said alli (pronounced Al-eye) could cost consumers $12 to $25 a week, and that an estimated 5 million to 6 million Americans a year would buy the over-the-counter drug.

Members of the FDA advisory panels concluded unanimously that the proposed over-the-counter version helped patients lose an extra 5 to 6 pounds during the six months they would take it. They also voted 12-to-3 that the drug appeared generally safe, although some members voiced concerns about repeated and long-term use.

Dr. Alastair Wood, chairman of the Nonprescription Drugs Advisory Committee, said risks with low-dose Xenical were low, and people would be better off taking alli than any of the countless, unapproved dietary supplements on the market.

"Is it better to be taking caffeine compounds or this? Probably this," said Wood, a professor of medicine and pharmacology at Vanderbilt University. "I think the drug is safe enough to be OTC. It's an OTC indication. Although there are some i's that need to be dotted and t's crossed, it's suitable for OTC use."

But Dr. Ruth Parker, a professor of medicine at Emory University, said she was concerned about "use and abuse" of the drug among teenagers and others who should not take the drug.

"I am concerned that this, while in the short term may be useful, in the long term it may not be," added FDA panel member Dr. Neal Benowitz of the University of California, San Francisco. "Is there any prospect six-month treatment is going to produce long-term benefits?"

But Benowitz, who ultimately voted to recommend approval of the drug, said "one benefit might be that people take less dietary supplements."

The FDA first approved Xenical, which works in the intestines where it blocks some of the fat people eat from being absorbed and digested, for sale as a prescription drug in 1999.

In 2004, GlaxoSmithKline paid Roche, developer of Xenical, $100 million for the right to try to get a half-dose version of the drug approved for over-the-counter sale in the United States.

"There is no magic pill for weight loss and orlistat is not a magic pill," Glaxo's senior vice president John Dent told the FDA panels. "Orlistat is a tool that will help people control their calorie intake and modify their diet."

But Dr. Sidney Wolfe of Public Citizen's Health Research Group, noting the decline in sales of prescription Xenical, urged the committees to reject the application, terming it a "desperate attempt to revive this barely effective drug by an OTC switch."

"The switch of orlistat to OTC status would be a serious, dangerous mistake in light of its marginal benefits," Wolfe added.

During Monday's meeting, FDA committee members questioned whether consumers would be able to distinguish alli from dietary supplements also sold as weight-loss aids which do not require regulatory approval.

The advisory committees ultimately conditioned their recommendation of approval on Glaxo's pledge to conduct longer-term studies on how alli is used once it is sold over-the-counter.

The Endocrinologic and Metabolic Drugs Advisory Committee, the other of the two committees meeting on alli, would also be the panel that would weigh in on the pending application by Sanofi-Aventis to sell a new prescription weight-loss drug, Acomplia (rimonabant). No date has been set for such a meeting.