arenas diet pill works by a slim margin,

Arenas Diet Pill Works by a Slim Margin, FDA Says

Sept. 14 (Bloomberg) -- Arena Pharmaceuticals Inc.s experimental diet pill works by a slim margin when taken twice daily, U.S. regulators said, sending shares down the most ever.
The medicine, lorcaserin, helps people lose 3 percent more weight than a placebo, short of the recommended 5 percent, Food and Drug Administration staff said in a report released today. Outside advisers to the agency will meet Sept. 16 in Adelphi, Maryland, to review the findings ahead of an FDA decision scheduled for late October.
Arena and partner Eisai Co. are racing against Vivus Inc. and Orexigen Therapeutics Inc. to introduce new treatments for the one-third of Americans who are obese. Lorcaserin is similar to fenfluramine, a component in the diet pill fen-phen that was withdrawn from the U.S. market in 1997 because of links to heart-valve damage.
Lorcaserin did not satisfy the guidances mean efficacy criterion, said Eric Colman, deputy director of the FDAs Division of Metabolism and Endocrinology Products, in a memo to the advisory panel included in the staff report. The proposed twice-daily dose did, by a slim margin, satisfy the categorical efficacy criterion.
Shares Plunge
Arena fell $2.68, or 39 percent, to $4.17 at 9:33 a.m. New York time in Nasdaq Stock Market composite trading. The decline was the most since shares began trading in July 2000. Before today, the San Diego-based company had almost doubled so far this year.
According to FDA recommendations released in 2007, medical products designed for weight management should help at least 35 percent of people lose at least 5 percent of their weight and double the proportion of the placebo-treated group, or they should work 5 percent better than placebo. Lorcaserin only barely satisfied the first criteria, and didnt meet the second, according to the FDA.
Lorcaserin is Arenas first product and has the proposed brand name Lorqess. Sales may reach $331.5 million a year by 2013, according to the average estimate of two analysts surveyed by Bloomberg. Eisai bought rights to sell the drug on July 1 and plans to give about a third of the revenue to Arena.
Brain Binder
The medicine binds to a receptor in the brain that controls appetite while avoiding a separate target thought to have contributed to irregular functioning of heart valves in about 30 percent of people who took Wyeths fen-phen. The drugmaker, now part of Pfizer Inc., set aside more than $21 billion to resolve almost 200,000 lawsuits involving the recalled diet pill.
Lorcaserin will be scrutinized for any potential effects on heart valves given the history of fenfluramine, said Thomas Wei, an analyst at Jefferies & Co. in New York, in a Sept. 9 note to clients. The FDA requested Arena rule out a 50 percent increased risk in valve damage.
It remains unclear if the company has met this threshold, Wei said in the note.
Ten milligrams of lorcaserin twice a day helped 47.1 percent of patients lose at least 5 percent of their weight after 52 weeks, compared with 22.6 percent on a placebo, in pooled data from more than 6,000 patients released in June. According to FDA recommendations, medical products designed for weight management should help at least 35 percent of people lose at least 5 percent of their weight, and is double the proportion of the placebo-treated group.
Overweight Americans
Two-thirds of American adults are overweight, raising their risk of diabetes, heart disease, high blood pressure and cancer, according to the 2008 National Health and Nutrition Examination Survey. More than one-third of American adults are obese, measured as a ratio between height and weight.
Sales of prescription weight-loss drugs fell 11 percent last year to $153.7 million, according to the research firm IMS Health Inc. in Norwalk, Connecticut. Of the almost 7.5 million prescriptions dispensed, four of every five were for generic phentermine, a component of fen-phen still sold as a short-term appetite suppressant.
The last prescription diet pill approved by the FDA, Basel, Switzerland-based Roche Holding AGs Xenical in 1999, has been linked to liver damage, and Abbott Park, Illinois-based Abbott Laboratories 13-year-old Meridia was tied to heart attacks, strokes and deaths in an FDA staff review yesterday.
Decision Dates
The agency is scheduled to decide on lorcaserin by Oct. 22, Vivuss Qnexa by Oct. 28, and Orexigens Contrave by Jan. 31. Orexigen, of San Diego, announced a licensing agreement with Osaka, Japan-based Takeda Pharmaceutical Co., Asias biggest drugmaker, on Sept. 2. Vivus, of Mountain View, California, failed to win the advisory panels backing for Qnexa.
I think all three of these pending drugs for weight loss will eventually be approved, Ira Loss, an analyst at Washington Analysis who has followed the FDA for more than three decades, said in a telephone interview on Sept. 9. The two drugs that are approved are really not very good. These cant be any worse and theyre all safer.
To contact the reporter on this story: Catherine Larkin in Washington at [email protected] .