New obesity pills try to shed past problems

The first of three new fat-fighting pills faces public scrutiny by U.S. regulatory advisers next week, as small biotechs target the growing number of obese Americans despite a checkered past for weight-loss drugs.

Vivus Inc, Arena Pharmaceuticals Inc, and Orexigen Therapeutics Inc are trying to succeed where earlier efforts flopped after several weight-loss drugs were linked to serious side effects.

The U.S. Food and Drug Administration will seek input from outside advisers July 15 on Vivus’ pill, Qnexa, for use with diet and exercise. If approved, it would be the first new prescription weight-loss drug in a decade in the United States, where two out of every three people are overweight.

The FDA’s review by a panel of outside experts follows a troubled history with obesity pills that either never gained approval, were pulled from the market after sales began, or were slapped with severe warnings.

“The history of weight-loss drugs is such that it’s a no-brainer that the FDA is going to take each and every one to an advisory panel,” said analyst Ira Loss, who follows the agency for Washington Analysis Corp.

An advisory panel is one of the last hurdles in a drug’s route to market. The FDA will make the final decision, but usually follows the advice of its advisers.

Qnexa, which combines the appetite suppressant Phentermine with the anti-seizure drug topiramate, aims to treat obese people and overweight patients with related health problems.

Vivus is trying to improve on the notorious “fen-phen” diet drug that combined fenfluramine with Phentermine. While fenfluramine was withdrawn, Phentermine is generally considered safe at low doses. Topiramate, sold generically and as Johnson & Johnson’s Topamax, is an anticonvulsant that can curb appetite.

MORE WEIGHT-LOSS DRUGS AHEAD

Rival products are not far behind.

Arena is seeking FDA approval for lorcaserin, a new type of drug that targets the part of the brain that controls metabolism and appetite. A public FDA meeting has been tentatively scheduled for Sept. 16, according to the company.

Orexigen has said the FDA will hold a Dec. 7 public review of its candidate, Contrave. A combination of naltrexone, used to fight alcohol and drug addiction, and the antidepressant bupropion, Contrave aims to target cravings, curb appetite and boost metabolism.

A TROUBLED PAST

Roughly 68 percent of U.S. adults, or nearly 211 million, are overweight or obese, according to the U.S. Centers for Disease Control and Prevention. Of those, more than 105 million are considered obese.

Weight can be managed through diet and exercise, but some medicines also can help.

American Home Products Corp, later renamed Wyeth and since last year part of Pfizer Inc, marketed fen-phen until 1997, when fatal heart valve problems forced the diet cocktail off the market.

Thousands of lawsuits followed, costing Wyeth some $21 billion in legal expenses. The company’s other drug, Redux, also contained a related chemical dexfenfluramine and was also taken off the market in 1997.

Shortly after, the FDA approved Meridia, now sold by Abbott Laboratories. That drug carries warnings about High Blood Pressure and a risk of heart attack and stroke in cardiovascular patients. It is no longer sold in Europe.

Roche Holding AG’s Xenical has been available since 1999, and GlaxoSmithKline markets a lower-dose, over-the-counter version called Alli. But it can cause serious liver problems, uncontrolled bowel movements and gas.

Last year, widely used Hydroxycut-brand diet supplements were pulled from store shelves after reports of liver damage.

The current options “are not that effective by themselves,” said Dr. Lawrence Cheskin, director of the Johns Hopkins Weight Management Center in Baltimore. He has served on an advisory board that provides input to Vivus.

SMALL COMPANIES TAKE ON BIG PROBLEM

The companies offering the new generation of pills hope theirs offer better results.

Side effects of the three potential new drugs include headaches, infection, nausea, constipation and dry mouth.

Orexigen Chief Executive Officer Michael Narachi said he was keeping an eye on the July 15 Vivus meeting to get a sense of the FDA’s latest stance on obesity products.

“The best-case scenario is all of these drugs get approved for some appropriate population,” he said. Each drug may be able to target a niche group, such as Contrave’s potential for obese patients who are also depressed.

Arena is pinning its hopes on the fact that its drug is the only one of the three to use an entirely new chemical.

“There’s clearly a need for better agents,” said Dominic Behan, Arena’s chief scientific officer and co-founder.

Representatives for Vivus declined to comment, except to say they expected the FDA to make its final decision by Oct. 28.

All three companies must prove their therapies will not repeat the past.

“Obesity is the Cape Hatteras of drug development,” Morningstar analyst Damien Conover said, “where all these ships wanted to go and they sunk.”

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By Susan Heavey and Lisa Richwine

WASHINGTON (Reuters)