Arena Pharmaceuticals Inc., the developer of an experimental obesity pill, said its drug passed a test showing it doesn't damage heart valves like fen-phen, the Wyeth combination treatment withdrawn in 1997.

Arena's product showed no increased heart risks compared with a placebo after a year of follow-up, in a study of almost 3,200 patients, the San Diego-based company said today in a statement. An independent monitoring group said the drug was safe to continue the trial. Detailed results on safety and effectiveness are expected early next year, Arena said.

The drug, lorcaserin, is designed to stimulate a protein in the brain that makes people feel full without boosting a similar protein that caused fen-phen to damage heart valves. If Arena's medicine can help people lose weight for a year, Arena said it will ask U.S. regulators for approval in 2009. The drug would be Arena's first marketed product and may generate more than $1 billion a year in sales, analysts said.

``This is a significant milestone for the company,'' said Dominic Behan, Arena's chief scientific officer, in a telephone interview. If the drug damaged heart valves, ``we would definitely expect to see an effect after one year,'' he said.

If Arena succeeds, it could tap into one of the most lucrative markets in the pharmaceutical industry. Medical expenses in the U.S. from obesity totaled $75 billion in 2003, half financed by taxpayers, according to the U.S. Centers for Disease Control and Prevention, and about two-thirds of American adults are overweight or obese.

More Heart Scans

Arena fell 13 cents, or 2 percent, to $6.31 March 14 in Nasdaq Stock Market composite trading. The stock dropped 19 percent since the beginning of the year through yesterday, underperforming an 11 percent decline in the Nasdaq Biotechnology Index.

Lorcaserin still needs to pass more heart scans, or echocardiograms, after patients in the study have been followed for 18 and 24 months, Behan said. The main goal of the trial, called Bloom, is to show that patients can lose 5 percent of their body weight if they take lorcaserin for a year.

An earlier clinical trial found that patients who took the same 10-milligram, twice-daily dose of lorcaserin being studied in the Bloom trial lost an average of 7.9 pounds over 12 weeks, compared with 0.7 pounds for those who took a placebo, Arena has said. The earlier study, which enrolled 469 patients, found no effect on heart valves.

Reducing Uncertainty

Passing the 12-month safety review could reduce uncertainty about the drug enough to stir interest among large drugmakers looking to form a partnership to co-market lorcaserin, Behan said. ``We think this can only help,'' he said.

If lorcaserin reaches the market, it would compete with Abbott Laboratories' Meridia and Roche Holding AG's Xenical, which have side effects that limit their use. Paris-based Sanofi-Aventis SA opted to withdraw its application to market another rival, Zimulti, in the U.S. in June after an FDA advisory panel raised questions about a link between the drug and suicides.

``Lorcaserin has the potential to be the best-in-class weight-loss agent, with $1+ billion in market potential if proven safe,'' said Carol Werther, an analyst with Summer Street Research Partners in Boston, in a Feb. 28 note to clients. Heart-valve damage with fen-phen was seen as early as three months, she said. Werther rates Arena a ``Buy'' with a $19 price target.

The drug is also being tested in two other one-year clinical trials enrolling a total of 3,750 patients. Results from those studies are expected in 2009, Behan said.

Enough Cash

Arena, founded in 1997, had an accumulated deficit of $479 million at the end of December, through developing lorcaserin, an insomnia treatment and other products. The company had $398 million in cash and investments at year-end, enough to pay for the ongoing lorcaserin clinical trials, Arena said.

The safety profile for a widely used obesity drug must be relatively benign to win approval from the U.S. Food and Drug Administration, said Arena Chief Executive Officer Jack Lief, in an interview in September.

``If we're doing bad things to heart valves, that's not acceptable,'' he said. ``If the drug increases headaches, that may be acceptable, because you can take a Tylenol and get rid of it.''

-bloomberg

__________________
Submissions | Hip-Hop 4 Obama