Arena Pharmaceuticals Obesity Drug Shot Down by FDA Panel

Xconomy San Diego — 

San Diego-based Arena Pharmaceuticals (NASDAQ: ARNA) and its partner, Japan-based Eisai Pharmaceuticals, suffered a big-time setback today in their quest to bring a new obesity drug to the U.S. market.

The FDA’s expert advisory panel on endocrinology and metabolic drugs said today in a 9-5 vote that lorcaserin (Lorqess) shouldn’t be approved for sale in the U.S. While the FDA has the ultimate authority to decide whether to give the green light, it usually follows the advice of its expert panels. The FDA’s deadline to make its decision on the drug is Oct. 22.

“Arena and Eisai believe that lorcaserin has a positive benefit-risk profile. Arena will work closely with the FDA as the agency completes its review of the lorcaserin new drug application,” Arena CEO Jack Lief said in an e-mailed statement.

The FDA panel’s vote shouldn’t come as a big surprise. A competing obesity drugmaker, Mountain View, CA-based Vivus (NASDAQ: VVUS) suffered a similar setback at an FDA advisory panel in July. And FDA staff issued some critical briefing documents about Arena’s drug in advance of today’s meeting, pointing out the drug passed common effectiveness standards by a “slim margin” and there appeared to be a higher risk of cancer in rats who got very high doses of the drug. The rat tumor concerns surprised investors on Tuesday, and prompted Arena to lose about 40 percent of its value. For more background on what Arena has at stake in lorcaserin, check out our coverage from earlier this week.