Arena Pharmaceuticals in deal to fund commercialization of obesity drug

Arena Pharmaceuticals in deal for obesity drug

Arena Pharmaceuticals Inc. said Thursday it has an agreement with Japan’s Eisai Inc. in a deal worth potentially more than $1.3 billion to fund commercialization of an obesity drug that could become Arena’s first product.

Arena’s lorcaserin is part of a wave of potential new treatments for a tough-to-treat problem that’s become an epidemic in developed countries.

San Diego-based Arena said Eisai will pay $50 million upfront for rights to sell lorcaserin in the U.S. In addition, Arena could get as much as $160 million in payments for reaching certain development targets and getting the drug approved by regulators, plus a $1.16 billion one-time payment in the future based on the level of annual sales.

Arena will manufacture the drug and Eisai will distribute it in the U.S.

Arena keeps the rights in other countries, Chief Executive Jack Lief told The Associated Press.

“That allows us to maximize our international opportunities,” he said.

Arena, which has no products on sale yet, reported at a medical conference Saturday on a late-stage weight-loss study of lorcaserin that included more than 6,000 patients. The company said that 47 percent of patients in the group taking lorcaserin lost at least 5 percent of their body weight, compared with 23 percent who lost that much in a comparison group taking dummy pills.

Doctors generally say that weight loss of 5 percent or more brings significant health benefits.

“With Esai, we have the right company to market lorcaserin in the United States, the right type of agreement to optimize lorcaserin’s medical and commercial potential” at the right time, Lief said.

The drug works by interacting with a brain receptor involved in appetite control and feelings of satiety, according to the company.

Lorcaserin, which has not yet been given a brand name, is part of a new wave of promising experimental obesity drugs. Three drugs are poised to reach what could be a very large and lucrative market around the same time — late this year or early next year.

The other two medicines are Qnexa, developed by Vivus Inc. of Mountain View, and Contrave, developed by Orexigen Therapeutics, also of San Diego.

All three drug candidates are being developed by small companies and are under review by the U.S. Food and Drug Administration.

Qnexa will be the first to be reviewed by an FDA panel of experts, at a meeting scheduled for July 15.

Lorcaserin is set for review by an FDA panel on Sept. 16, with a tentative deadline of Oct. 22 for the FDA to rule on approval.

Contrave is scheduled for a panel review on Dec. 7, and the agency is set to make a ruling on that drug by Jan. 31, 2011.

Finding a successful obesity treatment has been difficult, with numerous past drugs failing because of limited effectiveness, safety problems or unpleasant side effects such as loose stool.

But with Americans and people in many other countries getting fatter and fatter, any treatment that works well would be a blockbuster.

The market for obesity drugs alone is likely to be worth billions a year, and the new drugs might also turn out to help in treating diseases related to obesity, such as Type 2 diabetes and sleep apnea.

Qnexa, the Vivus drug, has been tested in multiple studies of patients with either diabetes or sleep apnea.

Multiple studies on research by the companies, including the latest on lorcaserin, were presented during the American Diabetes Association medical conference in Orlando, Fla., that wrapped up at the beginning of this week.