FDA to review first of 3 new weight loss drugs

July 12, 2010 By MATTHEW PERRONE , AP Business Writer

(AP) -- Dieters, doctors and investors get their first extensive look at the first of a trio of new weight loss drugs this week. The hope is that the new drugs can succeed where many others have failed: delivering significant weight loss without risky side effects.

With U.S. nearing 35 percent of the adult population, expectations are high for the first new prescription drug therapies to emerge in more than a decade. Even a modestly effective drug has blockbuster potential.

None of the three medicines represents a breakthrough in research. Drugmakers have made little headway in understanding and treating the causes of overeating. Two of the drugs submitted for approval simply combine existing drugs - an and an amphetamine - but have worrying side effects. The third, a new medication, is safer but less effective.

The quest for a blockbuster weight loss drug has been plagued for decades by safety issues. The most notable was Wyeth's diet pill fen-phen, which was pulled off the market in 1997 due to links to heart valve damage and lung problems.

The FDA is expected to post its review of Vivus Inc.'s pill Qnexa on Monday and will hold a public meeting Thursday to review the data. Orexigen Therapeutics Inc.'s Contrave is set for review in October, and Arena Pharmaceuticals Inc.'s lorcaserin is set for December.

"There's no obvious clear winner," said Leerink Swann analyst Steve Yoo. "If you look at different aspects, each drug shines."

To be considered effective, obesity drugs should reduce total body weight by at least 5 percent after one year, according to FDA guidance to companies.

Qnexa showed the best weight loss results in clinical trials, with patients losing between 13 percent and 15 percent of their body weight. But the drug also had the highest rate of patient dropouts due to side effects, which include memory and concentration problems.

Qnexa is a combination of two older drugs: the amphetamine phentermine and topiramate, an anticonvulsant drug sold by Johnson & Johnson as Topamax. According to the company, phentermine helps suppress appetite, while topiramate makes patients feel more satiated.

Contrave is also a combination pill, mixing an antidepressant with an anticonvulsant drug. The drug has shown weight loss between 5 percent and 10 percent with side effects such as nausea.

University of Liverpool Professor Jason Halford said drug companies are taking a multi-pronged approach to obesity therapies because science has shown there are multiple brain signals that drive food intake.

"We're using combinations of old drugs with a very broad spectrum of pharmacotherapy, it's very much the shotgun approach," said Halford, a health psychologist who has consulted for drug companies on obesity treatments.

The one truly novel drug under FDA review showed the weakest results in clinical trials. Arena Pharmaceuticals' lorcaserin is a first-of-a-kind drug that acts on serotonin, a brain chemical associated with feelings of well-being and satiation. But patients in company trials lost just 5 percent of their body weight.

While Arena's drug trails its competitors in weight loss, it appears to have the least side effects, an important factor in FDA approval.

Investors clearly favor Vivus in the three-way race. Shares of Vivus have nearly doubled over the past year to close Friday at $11.52.

Arena Pharmaceuticals shares have fallen nearly 4 percent over the past year on lackluster results for its drug. Orexigen shares have fallen 21 percent over the past year, to close Friday at $4.17, marking a bouncy descent from a June 2007 peak of $17.70 a share.

Decision Resources, a drug industry analysis firm, believes all three drugs could eventually win approval and find a place in the global obesity market. The firm expects the global market to soar from $500 million to $3.4 billion a year by 2018.

Still, the history of diet drugs is littered with stumbling blocks.

The diet drug fenfluramine, which was half of the fen-phen combination, was withdrawn in 1997 after it was linked with heart damage. The drug's combination with phentermine was popular but never approved by FDA.

Two years ago Sanofi-Aventis SA discontinued studies of its highly anticipated pill Acomplia due to psychiatric side effects, including depression and suicidal thoughts.

have kept the small number of weight-loss drugs currently on the market from being blockbuster sellers. Abbott Laboratories' appetite suppressant Meridia was pulled from the market in Europe last November due to data showing increased heart attack risks. And in May, the FDA warned consumers that the over-the-counter pill alli, which has been sold for years at a higher dose as the prescription drug Xenical, could cause severe liver damage. The drug works by limiting the amount of fat the body can absorb.

Derek Lowe, a pharmaceutical researcher and blogger, says the new combination drugs under review hold promise because they work on multiple brain chemicals that drive overeating.

"No single agent is going to shut down this behavior," said Lowe, whose blog "In the Pipeline" focuses on drug development. "But if you can come in and hit two or more of these different pathways at the same time, maybe then you'll get somewhere."

Explore further: FDA probes liver damage with weight loss pill alli


Related Stories

Researchers find clue to safer obesity drugs

November 25, 2008

(PhysOrg.com) -- Once hailed as a miracle weight-loss drug, Fen-phen was removed from the market more than a decade ago for inducing life-threatening side effects, including heart valve lesions. Scientists at UT Southwestern ...

Experimental weight-loss drug cuts appetite, burns more energy

January 8, 2008

The first clinical studies of an experimental drug have revealed that obese people who take it for 12 weeks lose weight, even at very low doses. Short-term studies also suggest that the drug, called taranabant—the second ...

New promising obesity drug may have huge potential

October 23, 2008

According to trials, a new obesity drug, Tesofensine, which may be launched on the world market in a few years, can produce weight loss twice that of currently approved obesity drugs. The Danish company Neurosearch and a ...

FDA panel backs 3 psychiatric drugs for kids

June 11, 2009

(AP) -- Advisers to the Food and Drug Administration said Wednesday that three blockbuster psychiatric drugs appear safe and effective for children and adolescents, despite side effects that can increase the risk of diabetes.

FDA drug approvals mostly flat in 2009

January 5, 2010

(AP) -- Drug approvals from the Food and Drug Administration were flat last year compared with 2008 and warnings fell, even as the agency's new leadership struck a tougher stance on safety.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Cow embryos reveal new type of chromosome chimera

May 27, 2016

I've often wondered what happens between the time an egg is fertilized and the time the ball of cells that it becomes nestles into the uterine lining. It's a period that we know very little about, a black box of developmental ...

Shaving time to test antidotes for nerve agents

February 29, 2016

Imagine you wanted to know how much energy it took to bike up a mountain, but couldn't finish the ride to the peak yourself. So, to get the total energy required, you and a team of friends strap energy meters to your bikes ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.