Arena obesity pill wins over U.S. advisers

An experimental obesity pill from Arena Pharmaceuticals Inc won the support of U.S. advisers on Thursday, as public health advocates push for new solutions to the nation's growing obesity epidemic.

A panel of outside experts to the Food and Drug Administration voted 18 to 4 to recommend approval of lorcaserin, bringing the drug a step closer to U.S. approval as one of the first new weight-loss treatments in over a decade.

Lorcaserin is Arena's most important product.

Shares of Arena, which were halted pending the panel vote, nearly doubled in value to $6.92 after closing at $3.66 on Wednesday.

Arena's pill is one of three new potential obesity treatments vying to gain U.S. approval and be the first new weight-loss treatment on the market after initial rejections over safety issues.

The FDA first rejected lorcaserin, which is being developed in partnership with Japanese drugmaker Eisai Co Ltd, in October 2010, citing potential cancer risks.

Arena resubmitted its application with more data after the 2010 rejection to show that the previous findings of tumors in rats did not apply to people, which seemed to soothe some of the FDA's concerns.

The advisory committee members still had some concerns about side effects, especially uncertainty about heart valve problems, but most said these concerns could be addressed in post-approval studies.

The panelists were also concerned about the drug's modest weight loss, but said overweight and obese patients needed more options.

"Currently the options available to obese patients are very limited, and severely obese patients are willing to accept a high degree of risk," said panel member Dr. Daniel Bessesen, chief of endocrinology at the Denver Health Medical Center.

"And while it isn't an ideal drug... I think it will be a useful adjunct," said Bessesen.

The FDA often follows panel recommendations, although it is not required to. It is due to make a final decision by June 27.

After the panel vote, Arena and Eisai said they were expanding their partnership.

If the drug is approved, Arena will manufacture lorcaserin at its facility in Switzerland, then pass it to Eisai for distribution in most of North and South America, including Canada, Mexico and Brazil.

Obesity, a leading cause of diabetes, heart disease and other serious health problems, has reached epidemic proportions in the United States with nearly a third of the population falling into the category.

The pricetag of obesity has also soared, with the condition contributing an additional $190 billion a year in healthcare costs, or one-fifth of all healthcare spending.

But the FDA has set a very high approval bar for weight loss drugs because such a large portion of the general population is likely to want to take them.