Approval of the first weight-loss drug in more than 20 years cameMonday afternoon when the FDA cleared dexfenfluraminehydrochloride (Redux), a product that's been available for years inEurope but had trouble getting clearance in the U.S.

Interneuron Pharmaceuticals Inc., of Lexington, Mass., licensed U.S.rights to Redux in 1990 from Paris-based Les Laboratoires Servier,which already is marketing the product in 65 countries. Interneuroninitially filed a new drug application in 1990, a process that's beenslowed by safety concerns.

Redux will be sold by Wyeth-Ayerst Laboratories, a Philadelphia-based subsidiary of American Home Products Corp., as a prescriptiontherapy. Redux, in combination with a reduced-calorie diet, isindicated for weight loss and management of that loss.

The organic molecule acts by stimulating production of serotonin, aneurotransmitter that influences appetite. Those taking Redux feelfull faster, thereby reducing calorie intake. The product will beavailable this summer and available in 15 mg tablets to be takentwice daily.

Interneuron will get royalties of up to 12 percent, Servier will get alittle less than 12 percent and Wyeth-Ayerst will pocket the rest. Thesignificant U.S. market for the product _ 45 million to 47 millionpeople if going strictly by approved labeling _ should mean Reduxwill be a big one for all three companies. Treatment will cost about$2 per day.

The news was released late Monday afternoon. NASDAQ haltedtrading right around the time the news came out. Still, Interneuron'sstock (IPIC) gained $3.63 to close at $37.13.

FDA approval "is the single most important decision in thecompany's history, especially for a small biotech company with noapproved products or revenues," said William Boni, Interneuron'svice president for corporate communications. "It means we have asource of revenue to look forward to over the coming years.Dexfenfluramine is the right product at the right time.

"Obesity clearly has been shown to have a physiological basis, ratherthan being will-power dependent," Boni said. "If that's the case itmakes sense to treat that condition with a drug, if that drug is safeand effective."

Redux is recommended for those with an initial body mass of 30kg/m2 (or 30 percent above healthy body weight) and those with 27kg/m2 (20 percent overweight) who have other risk factors, such ashypertension, diabetes and high cholesterol levels.

Boni said studies proved patients taking the drug lost and kept offtwice as much weight as those on placebo treatment, which involvedbeing put on a strict diet and behavior modification program. Thedrug group had the same diet and behavior modification programs.One-year studies showed Redux patients had significant weight lossduring the first four to six months and maintained that loss as long astherapy continued, up to 12 months. Studies haven't been doneassessing results after one year.

Boni said post-marketing studies will be conducted, although they arenot required by the FDA. Another important part of the approval forInterneuron, he said, is the company will implement a small salesforce, probably numbering several dozen, directed at physicianspecialists, such as those who treat diabetics.

For more on FDA advisory panel meetings on the drug, seeBioWorld Today issues of Sept. 29, 1995, and Nov. 17, 1995. n

-- Jim Shrine

(c) 1997 American Health Consultants. All rights reserved.